Separate opinion of Judge Xue

Document Number
154-20230713-JUD-01-02-EN
Parent Document Number
154-20230713-JUD-01-00-EN
Date of the Document
Document File
Bilingual Document File

SEPARATE OPINION OF JUDGE XUE
TABLE OF CONTENTS
Paragraphs
I. PROCEDURAL FAIRNESS FOR THE GOOD ADMINISTRATION OF JUSTICE 2-9
II. SUBSTANTIVE ISSUES IN THE PRESENT CASE 10-49
A. Continental shelf under customary international law as reflected in
Article 76 11-19
B. Relationship between the régimes of the continental shelf and of the
exclusive economic zone 20-36
C. State practice with regard to CLCS submissions 37-49
III. NICARAGUA’S SUBMISSIONS ON AN EXTENDED CONTINENTAL SHELF 50-60
1. I have voted in favour of the operative paragraph of the Judgment but on entirely different
legal grounds. I have serious reservations about the Court’s findings on the applicable law in the
present case. The legal ramifications it may exert on the régime of continental shelf are hard to tell.
I am obligated to place my position on the record.
I. PROCEDURAL FAIRNESS FOR THE GOOD
ADMINISTRATION OF JUSTICE
2. My reservation about the procedural fairness in the organization of oral proceedings has
been largely reflected in the joint declaration appended to the Order of 4 October 2022 in the present
case (Question of the Delimitation of the Continental Shelf between Nicaragua and Colombia beyond
200 Nautical Miles from the Nicaraguan Coast (Nicaragua v. Colombia), Order of 4 October 2022,
joint declaration of Judges Tomka, Xue, Robinson, Nolte and Judge ad hoc Skotnikov). With this
final decision settling the case, the oral proceedings on the merits were closed and, consequently, the
Parties did not have an oral hearing to make their final arguments on all the issues that still divided
them and to submit their final submissions to the Court. Procedurally, this practice is unprecedented
in the Court’s judicial history.
3. According to Article 48 of the Statute, the Court shall make orders for the conduct of the
case and decide the form and time in which each party must conclude its arguments. This power,
however, must be exercised in accordance with the principle of juridical propriety for the good
administration of justice. Article 31 of the Rules of Court provides that “[i]n every case submitted to
the Court, the President shall ascertain the views of the parties with regard to questions of procedure”.
Procedurally, the Court must ensure that each party is free to choose and follow its own judicial
strategy and to fully develop all its arguments. In this regard, the Court should exercise great caution
when controlling the oral proceedings so as to avoid jeopardizing the rights of the parties (ibid.,
para. 11, note 3, citing Mohammed Bedjaoui, “The ‘Manufacture’ of Judgments at the International
Court of Justice”, Pace Yearbook of International Law, 1991, Vol. 3, p. 44; Eduardo Jiménez de
Aréchaga, “The Amendments to the Rules of Procedure of the International Court of Justice”,
American Journal of International Law, 1973, Vol. 67 (1), p. 7).
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4. In its final written pleadings, Nicaragua has made three submissions. The first submission
concerns maritime delimitation between the continental shelf beyond 200 nautical miles (also
referred to as the “extended continental shelf”) as claimed by Nicaragua and Colombia’s maritime
area within 200 nautical miles from Colombia’s mainland baselines. The second and third
submissions relate to the maritime entitlements of Colombia’s maritime features that may overlap
with Nicaragua’s entitlement to an extended continental shelf. Apparently, Nicaragua’s submissions
concern both maritime entitlements of the Parties and delimitation. The legal questions posed by the
Court in the 4 October 2022 Order primarily address the issue of entitlement. Without hearing the
Parties on all the issues, both in law and in fact, and without making the entire case file accessible to
the public, the judicial process did not fully run its course. This is particularly questionable when the
Applicant has specifically requested the Court to proceed to a hearing on the merits.
5. Procedurally, even supposing that the answers to the legal questions were decisive for the
resolution of the whole case, the present approach adopted by the Court at this phase should still be
called into question. As the Applicant indicated, the legal questions posed by the Court had already
been substantially argued by the Parties in the course of the written proceedings of this case and
during the Territorial and Maritime Dispute (Nicaragua v. Colombia) case.
6. The first legal question posed by the Court initially arose from Nicaragua’s submission I (3)
in the Territorial and Maritime Dispute case, where Nicaragua requested the Court to define “a
continental shelf boundary dividing by equal parts the overlapping entitlements to a continental shelf
of both Parties”, which means that Nicaragua’s claim to a continental shelf extends beyond
200 nautical miles, as the distance between the mainland coasts of the Parties extends more than
400 nautical miles (Nicaragua v. Colombia, Judgment, I.C.J. Reports 2012 (II) (hereinafter the
“2012 Judgment”), p. 636, para. 17). The Court rejected Nicaragua’s request for the delimitation of
its extended continental shelf with Colombia’s maritime entitlements on the ground that Nicaragua
had not established that it has a continental margin that extends far enough to overlap with
Colombia’s 200-nautical-mile entitlement to the continental shelf, measured from Colombia’s
mainland coast. The Court stated that it was not in a position to delimit the continental shelf boundary
between Nicaragua and Colombia, as requested by Nicaragua, even using the general formulation
proposed by it (ibid., p. 669. para. 129). In this regard, the Court especially mentioned that it saw no
need to address the issue raised by the Parties as to whether a delimitation of overlapping entitlements
which involves an extended continental shelf of one State can affect a 200-nautical-mile entitlement
to the continental shelf of another State (ibid., pp. 669-670, paras. 129-130), a legal question that the
Court now considers has been answered by customary international law.
7. Moreover, during the oral proceedings in that case, Judge Bennouna posed the following
questions to the Parties:
 “Is the legal régime of the continental shelf for the portion located within the 200-nautical-mile
limit different from that for the portion located beyond this limit?”
 “Can the rules laid down in Article 76 of the 1982 United Nations Convention on the Law of the
Sea concerning the determination of the outer limit of the continental shelf beyond 200 nautical
miles today be considered as rules of customary international law?”
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In answering Judge Bennouna’s questions, the Parties went some way in answering the first question
posed by the Court in the Order of 4 October 2022 and gave their views on the criteria under
customary international law for the determination of the limit of the continental shelf beyond
200 nautical miles.
8. At the preliminary objections phase in the present case, Colombia contended that
Nicaragua’s first submission was a “reincarnation” of Nicaragua’s claim contained in its final
submission I (3) in the Territorial and Maritime Dispute case, in so far as it concerned delimitation
of extended continental shelf. It argued that, by virtue of res judicata, the Court was prevented from
entertaining it in the present case. The Court rejected Colombia’s objections, including its claim
based on res judicata, and upheld the admissibility of Nicaragua’s first submission. During the
written proceedings, the Parties significantly developed their arguments on Nicaragua’s entitlement
to an extended continental shelf and its relationship with Colombia’s entitlements within 200 nautical
miles.
9. From a procedural point of view, there seems to be no sound reason for the Court to depart
from its established practice by holding an oral proceeding to hear the views of the Parties only on
two legal questions. The Parties could have addressed them together with the factual and other legal
aspects of the case during the oral proceedings on the merits. If the settlement of the dispute between
the Parties on Nicaragua’s entitlement to an extended continental shelf indeed hinges entirely on the
answers to the legal questions, as recalled above, the matter should have been resolved much earlier
for the sake of judicial economy. As a judicial organ, the Court is supposed to know the law 
iura novit curia  and apply it to settle a dispute whenever it is called for. If the Court considers
that, under customary international law, maritime entitlements within 200 nautical miles of one State
take precedence over an extended continental shelf of another State, it should have decided, either in
the 2012 Judgment in the Territorial and Maritime Dispute case or in the Judgment of 17 March
2016 on preliminary objections in the present case (hereinafter the “2016 Judgment”), that, by virtue
of customary international law, Nicaragua’s claim of an extended continental shelf should be rejected
outright because Nicaragua is not entitled to such a claim and consequently no issue of delimitation
arises between the Parties. The dispute would thus have been settled there. Having unduly prolonged
the judicial process and having left unexamined all the technical and scientific evidence submitted
by the Parties, the Court’s approach, for whatever reason, cannot be deemed in conformity with the
principles of judicial propriety and has doubtfully facilitated judicial economy.
II. SUBSTANTIVE ISSUES IN THE PRESENT CASE
10. I agree with the majority that the negotiation and conclusion of the United Nations
Convention on the Law of the Sear (hereinafter “UNCLOS”) has, to a large extent, codified and
contributed to the progressive development of customary international law of the sea. However, I do
not share the reasoning given in the Judgment on the contemporary régime of the continental shelf.
The legal issue before the Court ultimately boils down to a question that often arises in continental
shelf delimitation, namely, the relationship between the extended continental shelf of one State and
maritime entitlements within 200 nautical miles from the baselines of another State. It bears on the
fundamental concept of natural prolongation in contemporary customary international law and the
“package deal” that was negotiated and eventually worked out at the Third United Nations
Conference on the Law of the Sea (hereinafter the “Law of the Sea Conference”). The reasoning of
the Judgment on the current state of the law, in my view, is neither persuasive nor reflective of general
State practice and opinio juris.
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A. Continental shelf under customary international law
as reflected in Article 76
11. The first question that the Court posed to the Parties in the Order of 4 October 2022
(hereinafter the “first question”) reads as follows:
“(1) Under customary international law, may a State’s entitlement to a continental
shelf beyond 200 nautical miles from the baselines from which the breadth of its
territorial sea is measured extend within 200 nautical miles from the baselines of another
State?”
This question basically asks an issue of entitlement on the basis of the relationship between two
criteria as set forth in Article 76, paragraph 1, of UNCLOS. If the two criteria are of equal
applicability, Nicaragua may be entitled to an extended continental shelf which overlaps with
Colombia’s entitlements within 200 nautical miles, provided its physical existence is established.
The case then calls for delimitation. If the answer to the question is in the negative, it means that the
distance criterion takes precedence over natural prolongation. Colombia’s 200-nautical-mile
entitlements prevail over Nicaragua’s claim; Nicaragua is not entitled to an extended continental
shelf that extends within 200 nautical miles of Colombia. Consequently, there is no issue of
delimitation between the Parties. The answer to the first question apparently has to be found in
customary international law.
12. Under customary international law, the continental shelf régime originates from the
concept of natural prolongation. The doctrine of the continental shelf was first recalled by the Court
in the North Sea Continental Shelf cases (North Sea Continental Shelf (Federal Republic of
Germany/Denmark; Federal Republic of Germany/Netherlands), Judgment, I.C.J. Reports 1969,
pp. 32-33, para. 47), in which the Court considered that the essential basis of the continental shelf is
the extended sovereign rights of the coastal State over the natural prolongation or continuation of its
land territory under the sea. Such rights exist ipso facto and ab initio (ibid., p. 22, para. 19). This
pronouncement was reiterated by the Court in subsequent cases. In the Tunisia/Libyan Arab
Jamahiriya case, for example, the Court stated that
“[t]he concept of natural prolongation . . . was and remains a concept to be examined
within the context of customary law and State practice. While the term ‘natural
prolongation’ may have been novel in 1969, the idea to which it gave expression was
already a part of existing customary law as the basis of the title of the coastal State.”
(Continental Shelf (Tunisia/Libyan Arab Jamahiriya), Judgment, I.C.J. Reports 1982,
p. 46, para. 43.)
13. Admittedly, contemporary customary international law on the definition of the continental
shelf was much influenced by the negotiations of the Law of the Sea Conference that lasted for nine
years. Not long after the Court delivered its Judgment in the North Sea Continental Shelf cases, the
United Nations General Assembly adopted a resolution in which it was stated
“that the definition of the continental shelf contained in the Convention on the
Continental Shelf of [1958] does not define with sufficient precision the limits of the
area over which a coastal State exercises sovereign rights for the purpose of exploration
and exploitation of natural resources, and that customary international law on the
subject is inconclusive” (resolution 2574 (XXIV) of 15 December 1969, adopted with
65 votes in favour, 12 against, and 30 abstentions; emphasis added).
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This resolution was adopted against the backdrop of the upcoming negotiations on the law of the sea
and growing concern over the prospects of deep sea-bed mining. The definition found in Article 1 of
the 1958 Convention did not provide a definitive limit of continental margin, leaving it open to
technical exploitability. The relevant article reads as follows:
“For the purpose of these articles, the term ‘continental shelf’ is used as referring
(a) to the seabed and subsoil of the submarine areas adjacent to the coast but outside the
area of the territorial sea, to a depth of 200 metres or, beyond that limit, to where the
depth of the superjacent waters admits of the exploitation of the natural resources of the
said areas; (b) to the seabed and subsoil of similar submarine areas adjacent to the coasts
of islands.”
Apparently, when the United Nations General Assembly disapproved of this definition as imprecise,
the focus of its attention was on the limits of the continental shelf but not its foundation; it was feared
that by recognizing an exploitability criterion, coastal States may, with the continuous advancement
of technology and science, extend their claim unrestrictedly, thus encroaching upon the common area
of the deep sea-bed and its resources, which were subsequently proclaimed as the “common heritage
of mankind” at the Law of the Sea Conference. It was this common interest that eventually led to the
new regulation of the continental shelf régime under Part VI of UNCLOS.
14. The outcome of the negotiations on Part VI of UNCLOS is a balanced solution between
the individual interest of coastal States and the common interest of the international community.
From the text of Part VI, it is not difficult to observe that the fundamental basis of the continental
shelf régime remains intact under the “package deal”; natural prolongation as the physical criterion
for the determination of the continental shelf is not replaced by a distance criterion, the criterion
applicable to the régime of the exclusive economic zone. There is no basis in customary international
law to suggest that restrictions imposed on the extent and use of the continental shelf beyond
200 nautical miles imply that the continental shelf is now under two régimes: the régime of
continental shelf within 200 nautical miles and the régime of the extended continental shelf. Either
based on the natural prolongation of its land territory or a distance of 200 nautical miles, every coastal
State is entitled to a single continental shelf; the substantive rights of the coastal State in the
continental shelf within and beyond 200 nautical miles from the baselines are generally the same,
which is affirmed by subsequent judicial and arbitral decisions, including the present Judgment
(Delimitation of the maritime boundary in the Bay of Bengal (Bangladesh/Myanmar), Judgment,
ITLOS Reports 2012, p. 96, para. 361; Bay of Bengal Maritime Boundary Arbitration (Bangladesh v.
India), Award of 7 July 2014, United Nations, Reports of International Arbitral Awards (RIAA),
Vol. XXXII, p. 38, para. 77; the present Judgment, para. 75).
15. The equal relationship between the two criteria can be further observed from the text of
Article 76, paragraph 1, which is considered by the Court as reflective of customary international
law (Territorial and Maritime Dispute (Nicaragua v. Colombia), Judgment, I.C.J. Reports 2012 (II),
p. 666, para. 118).
Article 76, paragraph 1, provides:
“The continental shelf of a coastal State comprises the sea-bed and subsoil of the
submarine areas that extend beyond its territorial sea throughout the natural
prolongation of its land territory to the outer edge of the continental margin, or to a
distance of 200 nautical miles from the baselines from which the breadth of the
territorial sea is measured where the outer edge of the continental margin does not
extend up to that distance”.
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By virtue of this provision, a distance criterion is added alongside the natural prolongation criterion
to the definition of the continental shelf. A coastal State whose continental margin does not extend
up to 200 nautical miles may extend its entitlement to 200 nautical miles, irrespective of geological
and other geophysical conditions. This entitlement provision, by its ordinary meaning, nowhere
indicates that the two criteria apply respectively to two distinct parts of the continental shelf, that is
to say, that the distance criterion applies to the continental shelf within 200 nautical miles while
natural prolongation criterion is only applicable to the extended continental shelf, as suggested in the
Judgment (para. 75). For any single continental shelf, it may be defined by either one of the criteria,
depending on the physical circumstances of the continental margin concerned. Between the two
criteria, there is neither priority nor precedence (Delimitation of the maritime boundary between
Guinea and Guinea-Bissau (Guinea/Guinea-Bissau), Award of 14 February 1985, RIAA, Vol. XIX,
p. 191, para. 116). If the distance criterion were indeed given precedence over natural prolongation
within 200 nautical miles, the text of Article 76, paragraph 1, must have been written differently to
indicate such a hierarchy, because it would otherwise annul the entitlement to certain extended
continental shelves that coastal States enjoy ipso facto and ab initio and would fundamentally change
the basis of continental shelf entitlements under customary international law. Apparently, no such
understanding can be found in the text of Article 76.
16. In analysing the terms of the continental shelf under Article 76, the Court infers an
assumption of negotiating States from the mechanism established under Article 76, paragraph 8, of
UNCLOS that an extended continental shelf would only extend into maritime areas that would
otherwise be located in the “Area”, hence denying the possibility that an extended continental shelf
of one State may extend within 200 nautical miles from the baselines of another State (Judgment,
para. 76). In this regard, it refers to Article 82 on payments and contributions to the International
Seabed Authority in respect of exploitation of the non-living resources of the extended continental
shelf and states that “[s]uch a payment would not serve the purpose of this provision in a situation
where the extended continental shelf of one State extended within 200 nautical miles from the
baselines of another State”. Furthermore, it observes that the issue before the Court with regard to
the extended continental shelf of one State extending within 200 nautical miles of another State “was
not debated” during the Law of the Sea Conference (Judgment, para. 76).
17. In the present case, Nicaragua’s claim obviously does not concern the Area, nor did the
Parties refer to it during the proceedings. It is true that the limitation on the continental shelf beyond
200 nautical miles and the Article 82 mechanism are designed to protect the Area and its resources
as the common heritage of mankind, but they are irrelevant to the present situation. It is questionable
whether an inference could be drawn from this treaty mechanism that the distance criterion was
provided as the primary entitlement to a continental shelf within 200 nautical miles to trump an
overlapping entitlement based on natural prolongation. The assumption inferred from Articles 76
and 82 of UNCLOS, even if established, does not necessarily lead to the conclusion that the
mechanism under Article 82 has the consequential effect of restricting a State’s entitlement to an
extended continental shelf from extending within 200 nautical miles of another State. What has been
agreed by the States in the “package deal” remains in the text of the treaty. What is not included
should continue to be governed by customary international law. The absence of discussions of the
issue during the negotiations at the Law of the Sea Conference does not reinforce the Court’s
reasoning. On the contrary, that fact weakens it. The negotiating parties did not debate the issue
simply because they saw no need to do so. As is observed,
“[t]he establishment of a maritime area in which the States concerned have shared rights
is not unknown under the Convention. The Convention is replete with provisions that
recognize to a greater or lesser degree the rights of one State within the maritime zones
of another.” (Bay of Bengal Maritime Boundary Arbitration (Bangladesh v. India),
Award of 7 July 2014, RIAA, Vol. XXXII, pp. 148-149, para. 507.)
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Overlapping continental shelf entitlements based on different criteria could well have been envisaged
when the distance criterion was introduced into Article 76, paragraph 1. Unless otherwise provided,
a hierarchical relationship between the two criteria cannot be construed from the simple fact that
there are a very large number of States parties to UNCLOS. Moreover, to what extent the relevant
treaty rules have passed into the corpus of customary international law is still a question to be
determined under customary international law. In other words, the Court has to ascertain whether
there is a general State practice and acceptance of such practice as law (opinio juris) that support a
customary rule as identified by the Court. In this regard, “two conditions must be fulfilled. Not only
must the acts concerned amount to a settled practice, but they must also be such, or be carried out in
such a way, as to be evidence of a belief that this practice is rendered obligatory by the evidence of
a rule of law requiring it.” (North Sea Continental Shelf (Federal Republic of Germany/Denmark;
Federal Republic of Germany/Netherlands), Judgment, I.C.J. Reports 1969, p. 44, para. 77; see also
Conclusions 2 and 9 of the Draft conclusions on identification of customary international law, with
commentaries, adopted by the International Law Commission in 2018 (hereinafter “ILC
Conclusions”, UN doc. A/73/10, pp. 122-156).
18. In determining the existence and content of a customary rule that may have evolved from
a treaty rule, the Court in the North Sea Continental Shelf cases highlighted an indispensable
requirement for the consideration of the State practice under the treaty rule concerned, according to
which,
“State practice, including that of States whose interests are specially affected, should
have been both extensive and virtually uniform in the sense of the provision invoked; —
and should moreover have occurred in such a way as to show a general recognition that
a rule of law or legal obligation is involved” (North Sea Continental Shelf (Federal
Republic of Germany/Denmark; Federal Republic of Germany/Netherlands),
Judgment, I.C.J. Reports 1969, p. 43, para. 74).
In assessing the evidence, regard must be had to the overall context, the nature of the rule and the
particular circumstances in which the evidence in question is to be found (Conclusion 3 of the ILC
Conclusions).
19. In assessing these two constitutive elements for the identification of a customary rule, the
Court relies heavily on the relationship of the régimes of the exclusive economic zone and of the
continental shelf as provided for in Article 56, paragraph 3, of UNCLOS and on States parties’
submissions to the Commission on the Limits of the Continental Shelf (hereinafter the “CLCS” or
“Commission”). It is this part of the reasoning that I find most unpersuasive and problematic. It flies
in the face of State practice and well-settled jurisprudence of the Court.
B. Relationship between the régimes of the continental shelf
and of the exclusive economic zone
20. In recalling the negotiating history of UNCLOS, the Court refers to the relationship
between the régimes of the exclusive economic zone and of the continental shelf. In the Court’s view,
since a coastal State enjoys in the exclusive economic zone, inter alia, sovereign rights over the
non-living resources in the sea-bed and subsoil within 200 nautical miles and since such rights shall
be exercised in accordance with the rules applicable to the continental shelf, the two régimes are
interrelated. Based on that link, the Court assumed that the entitlement to an extended continental
shelf may not extend within 200 nautical miles because such an extension would encroach on the
attendant exclusive economic zone of the coastal State. This inference, in my view, overstates the
import of Article 56, paragraph 3.
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21. First of all, the interrelationship between the régimes of the exclusive economic zone and
of the continental shelf as provided for in Article 56 does not give a prevailing effect to the exclusive
economic zone over the continental shelf. While Article 56, paragraph 3, links the two zones, it does
not go so far as to say that the two zones are inseparable in maritime delimitation and that maritime
entitlements within 200 nautical miles by their very nature shall take precedence over an extended
continental shelf entitlement. States’ positions as well as their practice are divided on the question
whether the two criteria under Article 76, paragraph 1, are of equal applicability or hierarchical in
effect. They differ as to whether the water column and the sea-bed within 200 nautical miles may be
delimited separately. Among scholars, views on the subject-matter also vary greatly1. This is indeed
an area that the “package deal” was ambiguous about. On the relationship between the two régimes,
one analysis of Article 56, paragraph 3, is pertinent in the present context:
“The text of Article 56 (3) is a clear indication of the applicable law, which might
result from the idea that the continental shelf and the EEZ are essentially dealing with
different natural resources. Whereas the continental shelf confers on coastal States
exclusive rights over the exploration and exploitation of the non-living resources and
sedentary resources in the seabed and subsoil, the EEZ is more concerned with living
resources in the water column, in particular fisheries. It is therefore in line with the
functional purposes of the two regimes if the continental shelf regime applies to the
seabed and subsoil, even if the area is within the reach of the EEZ.”2
This understanding is consistent with the concept of a single continental shelf. The continental shelf
régime applies to the sea-bed and subsoil irrespective of the basis of the entitlement, natural
prolongation or distance. While the inclusion of the sovereign rights over the sea-bed and subsoil in
the régime of the exclusive economic zone may reinforce the continental shelf entitlement within
200 nautical miles, Article 56, by its own terms, only concerns the content and exercise of substantive
rights.
22. Judicial and arbitral decisions generally recognize the autonomy and distinction of the two
régimes. In the present case, however, the Court draws a different reading from its 1985 Judgment
in the Continental Shelf (Libyan Arab Jamahiriya/Malta) case, where the Court observed that,
“[a]lthough there can be a continental shelf where there is no exclusive economic zone, there cannot
be an exclusive economic zone without a corresponding continental shelf” (Judgment, I.C.J. Reports
1985, p. 33, para. 34). Based on this statement, the Court now considers that, with the distance
criterion as the sole basis of entitlement of the coastal State to both the exclusive economic zone and
the continental shelf within 200 nautical miles, an extended continental shelf of one State may not
extend within 200 nautical miles of another State.
23. This finding, first of all, implies that, with the distance criterion applicable to both régimes,
the concept of the continental shelf within 200 nautical miles has been absorbed by that of the
exclusive economic zone under the contemporary law of the sea, an implication that the Court
categorically rejected in the same Judgment (see ibid., p. 33, para. 33). Following the above
statement cited by the Court, the Court in that case went on stating that,
1 Malcolm D. Evans, “Delimitation and the Common Maritime Boundary”, British Yearbook of International Law,
1994, Vol. 64 (1), p. 283; Xuexia Liao, “Is There a Hierarchical Relationship between Natural Prolongation and Distance
in the Continental Shelf Delimitation?”, The International Journal of Marine and Coastal Law, 2018, Vol. 33, pp. 105-110.
2 Xuexia Liao, “Is There a Hierarchical Relationship between Natural Prolongation and Distance in the Continental
Shelf Delimitation?”, The International Journal of Marine and Coastal Law, 2018, Vol. 33, pp. 106-107.
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“for juridical and practical reasons, the distance criterion must now apply to the
continental shelf as well as to the exclusive economic zone; and this quite apart from
the provision as to distance in paragraph 1 of Article 76. This is not to suggest that the
idea of natural prolongation is now superseded by that of distance. What it does mean
is that where the continental margin does not extend as far as 200 miles from the shore,
natural prolongation . . . is in part defined by distance from the shore, irrespective of the
physical nature of the intervening sea-bed and subsoil. The concepts of natural
prolongation and distance are therefore not opposed but complementary; and both
remain essential elements in the juridical concept of the continental shelf.” (Continental
Shelf (Libyan Arab Jamahiriya/Malta), Judgment, I.C.J. Reports 1985, p. 33, para. 34;
emphasis added.)
This statement shows that the interrelationship between the two régimes as defined in Article 56,
paragraph 3, is not conclusive on the question that the Court is dealing with in the present case,
namely, whether there is priority accorded to the entitlement within 200 nautical miles over an
extended continental shelf. Moreover, the factual situation of that case is entirely different from the
present one. In the former, the distance between the parties is less than 400 nautical miles, where
geographical or geophysical factors could be disregarded, while in the latter, the Applicant’s claim
to an extended continental shelf depends on the technical and scientific evidence that may establish
the existence of the natural prolongation of its land territory. Once the natural prolongation is
established, the Applicant is entitled to the extended continental shelf. What the Court stated in the
context of the Libyan Arab Jamahiriya/Malta case did not address the question of entitlement but of
delimitation. At the time of that case, with UNCLOS not yet in force and the customary status of
Article 76, paragraph 1, with regard to the distance criterion still in doubt, the Court took the legally
permissible extent of the exclusive economic zone appertaining to a given State as “one of the
relevant circumstances to be taken into account for the delimitation of the continental shelf” of that
State (ibid., p. 33, para. 33; emphasis added). By granting greater importance to the element of
distance, which is common to both régimes, in the delimitation of continental shelf within
200 nautical miles, the Court only tried to reach an equitable solution but not to pronounce a general
rule restricting natural prolongation.
24. Even supposing that the Court’s statement in the Continental Shelf (Libyan Arab
Jamahiriya/Malta) case did constitute a general legal pronouncement, one may still wonder when
the putative rule as identified by the Court in this case formed part of customary international law,
because the judicial and arbitral decisions and State practice on the delimitation of continental shelf
subsequent to the 1985 Judgment do not support such a proposition.
25. In the Bay of Bengal cases, the International Tribunal for the Law of the Sea (ITLOS) and
the arbitral tribunal established under Annex VII of UNCLOS respectively delimited the maritime
boundary including the extended continental shelf between the parties to each case. The adjustment
of the provisional equidistance line resulted in a “grey area” of limited size in both cases, which is
located within the 200-nautical-mile limit of the coast of one party but on the other party’s side of
the line that delimits the parties’ continental shelves (Delimitation of the maritime boundary in the
Bay of Bengal (Bangladesh/Myanmar), Judgment, ITLOS Reports 2012, p. 119, para. 463; Bay of
Bengal Maritime Boundary Arbitration between Bangladesh and India, Award of 7 July 2014, RIAA,
Vol. XXXII, p. 147, para. 498). The Court dismisses the Applicant’s argument based on these cases,
which it considers irrelevant for the consideration of the present case, because, in its view, the grey
area is “an incidental result” of the adjustment of the provisional equidistance line and the
circumstances in those cases are distinct from the situation in the present case (Judgment, para. 72).
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26. In Somalia v. Kenya  a case it has recently adjudicated  the Court observed that if the
delimitation line, as determined, continues on the course beyond 200 nautical miles, it might give
rise to an area of limited size lying within 200 nautical miles of the coast of Somalia but on the
Kenyan side of the boundary, thus resulting in a similar “grey area” as in the Bay of Bengal cases
(Maritime Delimitation in the Indian Ocean (Somalia v. Kenya), Judgment, I.C.J. Reports 2021,
p. 277, para. 197). The Court again dismisses the relevance of the case, stating that the grey area is
merely a possibility and that, therefore, there is no need to take it into account (Judgment, para. 73).
27. This approach taken by the Court appears hasty and evasive. In these three cases, the “grey
area”, albeit incidental in nature and small in size, is in itself a piece of hard evidence that disproves
at least the inseparability of the two zones in the maritime delimitation. Convenient or not, it evinces
that the exclusive economic zone does not dictate the delimitation of the continental shelf. As ITLOS
observed in the Bangladesh/Myanmar case,
“the legal regime of the continental shelf has always coexisted with another legal regime
in the same area. Initially that other regime was that of the high seas and the other States
concerned were those exercising high seas freedoms. Under the Convention, as a result
of maritime delimitation, there may also be concurrent exclusive economic zone rights
of another coastal State.” (Delimitation of the maritime boundary in the Bay of Bengal
(Bangladesh/Myanmar), Judgment, ITLOS Reports 2012, p. 121, para. 475.)
Evidently, these judicial and arbitral organs do not consider that there existed a customary rule by
which an extended continental shelf of one State may not extend within the exclusive economic zone
of another State, as a matter of entitlement. When an overlap of entitlements occurs, the matter is
one of delimitation. Article 83 of UNCLOS, on purpose, leaves sufficient room for the relevant
circumstances of each case to be considered in the delimitation process.
28. In practice, States not only claim an entitlement to an extended continental shelf that may
extend within 200 nautical miles of another State, but also draw maritime boundaries by agreement
that delimit the exclusive economic zone and the continental shelf separately. They do it either by
separate agreements dealing with different zones, or simply by drawing different boundary lines
within the same agreement.
29. Australia and Indonesia, for example, concluded an agreement on the continental shelf
boundary in the Timor and Arafura Seas in 1972 (Agreement between the Government of the
Commonwealth of Australia and the Government of the Republic of Indonesia establishing certain
seabed boundaries in the area of the Timor and Arafura Seas, supplementary to the Agreement of
18 May 1971, concluded 9 October 1972, entered into force 8 November 1973, United Nations,
Treaty Series (UNTS), Vol. 974, p. 319). In 1997, the two States concluded another agreement on the
exclusive economic zone boundary and the western extension of the sea-bed boundary (Agreement
between the Government of Australia and the Government of the Republic of Indonesia establishing
an exclusive economic zone boundary and certain seabed boundaries, concluded 14 March 1997, not
yet in force, International Legal Materials, 1997, Vol. 36, p. 1053). The latter agreement drew the
continental shelf boundary on the basis of the geological and geophysical factors of the Timor
Trough, while the boundary of the exclusive economic zone was drawn on the basis of distance; the
former line is closer to the Indonesian side. As a result of these two agreements, there are several
overlapping areas where Australia’s extended continental shelf is subjacent to Indonesia’s exclusive
economic zone (see illustrative map 1). For the purpose of management, the Agreement contains a
specific provision regulating, inter alia, the rights and obligations of each party in the areas of
overlapping jurisdiction. It affirms Indonesia’s sovereign rights of exclusive economic zone in the
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water column and Australia’s sovereign rights of continental shelf in the sea-bed3. Although the
Agreement has not yet entered into force, it manifests that the parties did not consider there existed
a customary rule by which Australia could not, by law, claim its entitlement to an extended
continental shelf that extends within Indonesia’s 200 nautical miles from its baselines.
3 Article 7 of the Agreement reads as follows:
“Areas of overlapping jurisdiction
In those areas where the areas of exclusive economic zone adjacent to and appertaining to a Party
(the First Party) overlap the areas of seabed adjacent to and appertaining to a Party being the other Party
(the Second Party):
(a) the First Party may exercise exclusive economic zone sovereign rights and jurisdiction provided for in
the 1982 Convention in relation to the water column;
(b) the Second Party may exercise continental shelf sovereign rights and jurisdiction provided for in the
1982 Convention in relation to the seabed;
(c) the construction of an artificial island shall be subject to the agreement of both Parties. An ‘artificial
island’ for the purposes of this Article is an area of land, surrounded by water, which is above water at
high tide by reason of human intervention;
(d) the Second Party shall give the First Party three months notice of the proposed grant of exploration or
exploitation rights;
(e) the construction of installations and structures shall be the subject of due notice and a permanent means
of giving warning of their presence must be maintained;
(f) (i) any installation or structure which is abandoned or disused shall be removed by the Party which
authorised its construction in order to ensure the safety of navigation, taking into account any
generally accepted international standards established in this regard by the competent international
organisation;
(ii) such removal shall also have due regard to fishing and to the protection of the marine environment.
Appropriate publicity shall be given to the depth, position and dimensions of any installations or
structures not entirely removed;
(g) the construction of a fish aggregating device shall be the subject of due notice;
(h) the Party constructing an artificial island, installation, structure or fish aggregating device shall have
exclusive jurisdiction over it;
(i) marine scientific research shall be carried out or authorised by a Party in accordance with the 1982
Convention and such research shall be notified to the other Party;
(j) the Parties shall take effective measures as may be necessary to prevent, reduce and control pollution
of the marine environment;
(k) each Party shall be liable in accordance with international law for pollution of the marine environment
caused by activities under its jurisdiction;
(l) any island within the meaning of Article 121.1 of the 1982 Convention which emerges after the entry
into force of this Treaty shall be the subject of consultations between the Parties with a view to
determining its status;
(m) neither Party shall exercise its rights and jurisdiction in a manner which unduly inhibits the exercise of
the rights and jurisdiction of the other Party; and
(n) the Parties shall cooperate with each other in relation to the exercise of their respective rights and
jurisdiction.”
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Illustrative map 1
(reproduced from Department of State of the United States of America, “Limits in the Seas
(No. 141)  Indonesia: Archipelagic and other Maritime Claims and Boundaries”,
September 20144)
30. The agreement on maritime boundaries concluded between Australia and Papua New
Guinea is another example (Treaty between Australia and the Independent State of Papua New
Guinea concerning sovereignty and maritime boundaries in the area between the two countries,
including the area known as Torres Strait, and related matters, concluded 18 December 1978, entered
into force 15 February 1985, UNTS, Vol. 1429, p. 207). Under Article 4 of this Treaty, two maritime
boundaries are established between the two States. The first line is the continental shelf boundary
concerning “seabed jurisdiction”, which is defined as “sovereign rights over the continental shelf in
accordance with international law, and includes jurisdiction over low-tide elevations, and the right
to exercise such jurisdiction in respect of those elevations, in accordance with international law”5.
The second line is the boundary relating to fisheries jurisdiction, defined as “sovereign rights for the
purpose of exploring and exploiting, conserving and managing fisheries resources other than
sedentary species”6. Based on the co-ordinates of the two boundaries, it is shown that, while the two
boundaries in the eastern and western sections coincide, the two boundaries are separate in the middle
section in the area known as the Torres Strait (see illustrative map 2). Papua New Guinea, like
Indonesia, accepted Australia’s position without any reservation. This treaty remains in force to date.
4 Available at https://www.state.gov/wp-content/uploads/2020/02/LIS-141.pdf, p. 12.
5 Article 1 (1) (i) and Article 4 (1).
6 Article 1 (1) (b) and Article 4 (2).
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Illustrative map 2
(reproduced from Department of Foreign Affairs and Trade of Australia, “Guidelines
for Traditional Visitors Travelling under the Torres Strait Treaty”7)
31. Australia reiterated its position on the natural prolongation criterion during the Timor Sea
Conciliation with Timor-Leste on the basis of Article 76, paragraph 1, of UNCLOS in light of the
geological and geomorphological situation of the Timor Trough in the Timor Sea (Timor-Leste v.
Australia, Permanent Court of Arbitration, Case Number 2016-10, Opening Session Transcript,
29 August 2016, p. 91). Although the parties ultimately reached a delimitation agreement
establishing a single maritime boundary for both the exclusive economic zone and the continental
shelf, the Preamble of the Treaty expressly states that “the settlement contained in this Treaty is based
on a mutual accommodation between the Parties without prejudice to their respective legal positions”
(Treaty between the Democratic Republic of Timor-Leste and Australia establishing their maritime
boundaries in the Timor Sea, concluded 6 March 2018, entered into force 30 August 2019, [2019]
Australian Treaty Series 16; emphasis added).
32. A more recent example is the delimitation agreement between Indonesia and the
Philippines concerning the delimitation of the exclusive economic zone in the Celebes Sea concluded
in 2014 (Agreement between the Government of the Republic of Indonesia and the Government of
the Republic of the Philippines concerning the delimitation of the exclusive economic zone
boundary, concluded 2 May 2014, entered into force 1 August 2019, UNTS, Vol. 3324, p. 1). The
distance between the parties in the area in the Celebes Sea is less than 400 nautical miles. In
delimiting the boundary of exclusive economic zones between the two States, the parties took
account of the provisions of UNCLOS and the principles applicable to delimitation. The Agreement
7 Available at https://www.dfat.gov.au/geo/torres-strait/guidelines-for-traditional-visitors-travelling-under-thetorres-
strait-treaty.
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specifically provides that “[t]his Agreement shall not prejudice any rights or positions of the
Contracting Parties with regard to the delimitation of the Continental Shelf boundary”8. Apparently,
the parties to the Agreement do not consider that the boundary of the exclusive economic zone is
decisive for the delimitation of the continental shelf boundary within 200 nautical miles.
33. Similar practice can also be found in other regions. Denmark and the United Kingdom, for
instance, reached an agreement on the maritime delimitation in the area between the Faroe Islands
and the United Kingdom in 1999 (Agreement between the Government of the Kingdom of Denmark
together with the Home Government of the Faroe Islands, on the one hand, and the Government of
the United Kingdom of Great Britain and Northern Ireland, on the other hand, relating to the Maritime
Delimitation in the area between the Faroe Islands and the United Kingdom, concluded 18 May 1999,
entered into force 21 July 1999, United Kingdom Treaty Series (UKTS), 1999, No. 76). Under the
Agreement, the parties delimited the continental shelf in the area and the waters superjacent to the
continental shelf in part of the area and established a special régime, called “the Special Area”, in the
remaining part. The parties made special arrangements for the exercise of fisheries jurisdiction and
rights in the Special Area. In a subsequent protocol concluded in 2012 to the Agreement, the parties
established exclusive economic zones in the waters as previously delimited and decided to retain the
previous boundaries and the Special Area as drawn in the Agreement (UKTS, 2014, No. 22). From
the maritime boundary shown in illustrative map 3 reproduced below, one can see that the Special
Area as a water column is separated from the continental shelf of either party.
Illustrative map 3
(found in Jonathan I. Charney and Robert W. Smith (eds.), International Maritime
Boundaries, 2002, Vol. IV, p. 2955)
8 Article 1, paragraph 3, of the Agreement.
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34. There are other bilateral maritime delimitation agreements, where one party’s extended
continental shelf overlaps with the exclusive economic zone of another party (see Agreement
between the United States of America and the Union of Soviet Socialist Republics on the maritime
boundary, concluded 1 June 1990, applied provisionally since 1 June 1990, Law of the Sea Bulletin,
No. 17, April 1991, p. 15; Treaty between the Kingdom of Norway and the Russian Federation
concerning maritime delimitation and cooperation in the Barents Sea and the Arctic Ocean,
concluded 15 September 2010, entered into force 7 July 2011, Law of the Sea Bulletin, No. 77, 2012,
p. 24)9.
35. In support of its claim, the Respondent refers to Article 2, paragraph 1, of the Treaty
between the Federated States of Micronesia and the Republic of Palau concerning maritime
boundaries and cooperation on related matters, which provides that “no Party shall claim an extended
continental shelf that intrudes into the Exclusive Economic Zone . . . of the other Party” (concluded
16 July 2006, entered into force 16 February 2016, UNTS, Vol. 3210, p. 1). This evidence, contrary
to the position of the Respondent, proves that these two States do not consider that there is a
customary rule that prohibits an extended continental shelf from extending within 200 nautical miles
from the coast of another State, because otherwise such a clause would be unnecessary.
36. Admittedly, States may make special arrangements through bilateral agreements, not
necessarily guided by generally applicable law. Nonetheless, such practice supports the settled
jurisprudence that the régimes of the exclusive economic zone and of the continental shelf, though
interrelated, are distinct and may be delimited separately. Although a single maritime boundary is
generally preferred for the convenience of management, that rationale for the delimitation does not
have a restrictive effect on the entitlement to the extended continental shelf.
C. State practice with regard to CLCS submissions
37. With regard to the submissions of States to the CLCS, the Court notes that the vast majority
of States parties to the Convention that have made submissions to the CLCS have chosen not to assert
therein limits that extend within 200 nautical miles from the baselines of another State. Without any
examination of the submissions of the “vast majority of those States”, the Court considers that “the
practice of States before the CLCS is indicative of opinio juris, even if such practice may have been
motivated in part by considerations other than a sense of legal obligation” (Judgment, para. 77).
Recalling some inconsistent practice of “a small number of States”, the Court takes the view that,
“[t]aken as a whole, the practice of States may be considered sufficiently widespread and uniform
for the purpose of the identification of customary international law”. It further states that, given its
extent over a long period of time, this State practice may be seen as an expression of opinio juris
9 In the Agreement between the United States of America and the Union of Soviet Socialist Republics on the
Maritime Delimitation, the boundary line as determined results in two areas, so-called “special areas”, in which one party’s
exclusive economic zone is superjacent to the continental shelf of the other party. Pursuant to Article 3, each party permits
the other party to exercise “the sovereign rights and jurisdiction derived from exclusive economic zone jurisdiction” that
the other party would otherwise be entitled to exercise under international law. To put it in more simple terms, they transfer
their EEZ rights to each other without changing the maritime title of the respective areas. In the Treaty between the
Kingdom of Norway and the Russian Federation concerning Maritime Delimitation and Cooperation in the Barents Sea
and the Arctic Ocean, the maritime boundary line also produces a “Special Area” which lies within 200 nautical miles of
Norway and beyond 200 nautical miles of the Russian Federation. Article 3 of the Treaty provides that the Russian
Federation shall be entitled to exercise EEZ rights and jurisdiction that Norway would otherwise be entitled to exercise
under international law. It also provides, however, that the Russian Federation’s exercise of such rights and jurisdiction
“derives from the agreement of the parties and does not constitute an extension of its exclusive economic zone” (emphasis
added). Legally speaking, therefore, the Russian Federation’s extended continental shelf is subjacent to the exclusive
economic zone of Norway.
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(Judgment, para. 77). This is a rather loose statement on the practice of States. The Court did not
even bother to address exactly what practice amounts to an expression of opinio juris.
38. First of all, it is necessary to examine the character of the State submissions to the CLCS.
Article 76, paragraph 10, of UNCLOS states that “[t]he provisions of this article are without
prejudice to the question of delimitation of the continental shelf between States with opposite or
adjacent coasts”. Accordingly, the claim that a State has made in its submission to the CLCS may
not be final and binding on its position with regard to the questions of entitlement and delimitation;
a State may leave out a certain portion of its claim in its submission if it deems it necessary, which
does not affect that State’s position in the delimitation. This understanding is supported by the terms
of the CLCS’s mandate and State practice. Pursuant to Rule 46 of the Rules of Procedure of the
CLCS and paragraph 5 (a) of Annex I to the Rules of Procedure, in the case where a land or maritime
dispute exists, the Commission shall not consider and qualify a submission made by any of the States
concerned in the dispute, unless prior consent is given by all the parties to the dispute.
Understandably, in order to have their submissions considered and qualified by the Commission,
States may refrain from extending their continental shelf entitlement within 200 nautical miles from
the coast of other States with a view to avoiding a dispute. Such restraint may be exercised because
of an agreement of the States concerned, a prior unilateral commitment, or a special arrangement.
Some States have made several submissions to the CLCS in respect of their separate territorial areas.
Their claims to an extended continental shelf with respect to those areas do not consistently refrain
from encroaching upon the 200-nautical-mile entitlement of another State. For instance, France’s
submissions in respect of the areas of French Guiana and New Caledonia and in respect of French
Polynesia stop at 200 nautical miles from the coasts of neighbouring States, but its submission
concerning Saint Pierre and Miquelon extends within 200 nautical miles from the coast of Canada.
When Canada raised its objection to the latter submission on the ground that the maritime zones of
Saint Pierre and Miquelon had been definitely settled by arbitration, France maintained that the
arbitral tribunal declared that the question (of an entitlement to a continental shelf beyond
200 nautical miles) did not fall within its competence. It further underscored that “those claims do
not run counter to the United Nations Convention on the Law of the Sea or any rule of international
law” (Note Verbale from the Permanent Mission of France to the United Nations, dated 17 December
2014; emphasis added). Evidently, no consistent State practice can be identified from States’
submissions to the CLCS.
39. When the Court affirms the practice of the “vast majority of States parties” for the
determination of the customary rule, it primarily relies on the 93 submissions from 73 States and the
Cook Islands received by the CLCS so far. According to Colombia, among those 93 submissions,
38 do not reach the 200-nautical-mile limit of another States and, therefore, are irrelevant. Of the
remaining 55 submissions, 51 are said by Colombia to have chosen not to extend the continental
shelf within 200 nautical miles from the coast of other States; in its view, only four States have made
the claim encroaching upon the entitlement within 200 nautical miles of another State10. At first sight,
this looks overwhelmingly persuasive. For the purpose of the present case, however, that practice
obviously needs further scrutiny.
40. Notwithstanding Article 76, paragraph 10, of UNCLOS and the above-mentioned CLCS
rules, studies show that the practice of States is not as certain and consistent as is suggested.
Individually, almost one third of the States that are said to have chosen not to claim their extended
continental shelf within 200 nautical miles of another State have already concluded bilateral
agreements with their neighbouring States on maritime delimitation within 200 nautical miles. That
fact may have a direct bearing on the States’ decision to exercise restraint in their CLCS submissions.
Moreover, as mentioned above, some of the said States have indeed claimed an extended continental
10 These four States include China, the Republic of Korea, Nicaragua and Somalia.
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shelf that extends within 200 nautical miles from the baselines of another State in the delimitation.
In this regard, the most illustrative example is the recent case between Mauritius and the Maldives.
41. In the Mauritius/Maldives case before an ITLOS Special Chamber, the Maldives claims
an extended continental shelf that extends within 200 nautical miles from the baselines of the Chagos
Archipelago (Mauritius). While this is not immediately apparent from the publicly available
Executive Summary of July 2010 of the Maldives’ Submission to the CLCS and the accompanying
maps, the ITLOS Special Chamber noted the existence of such an overlap (Delimitation of the
maritime boundary in the Indian Ocean (Mauritius/Maldives), Preliminary Objections, Judgment of
28 January 2021, para. 332; Delimitation of the maritime boundary in the Indian Ocean
(Mauritius/Maldives), Judgment of 28 April 2023, para. 257). The Maldives itself “confirm[ed] its
position that the Maldives’ entitlement to the continental shelf beyond 200 nautical miles from its
baseline can be . . . extended [within the 200-nautical-mile limit of Mauritius]”
(ITLOS/PV.22/C.28/4, p. 7). Mauritius claimed that the Maldives cannot extend its continental shelf
into the exclusive economic zone of Mauritius, because it had undertaken a specific commitment not
to do so (Delimitation of the maritime boundary in the Indian Ocean (Mauritius/Maldives), Judgment
of 28 April 2023, para. 260). Indeed, Mauritius itself contended that, “if Maldives were entitled to
claim an outer continental shelf within 200 Miles of the baselines of Mauritius, so too could
Mauritius, correspondingly, claim an outer continental shelf that encroaches within 200 Miles of
Maldives” (ITLOS/PV.22/C28/6, p. 29). Ultimately, for reasons concerning the circumstances of that
case, the Special Chamber considered that it was
“not required to address the question whether the Maldives has an entitlement to a
continental shelf beyond 200 nm in the relevant area or the question whether the
Maldives’ entitlement to a continental shelf beyond 200 nm may extend within the
200 nm limit of Mauritius” (Delimitation of the maritime boundary in the Indian Ocean
(Mauritius/Maldives), Judgment of 28 April 2023, para. 275).
The practice of both Mauritius and the Maldives in relation to the latter’s extended continental shelf
reduces the weight of the evidence presented by Colombia. The Maldives’ “restraint” is not based on
a legal obligation derived from a customary rule, nor is Mauritius’s objection to the submission of
the Maldives to the CLCS based on customary international law.
42. Responses to the submissions of the four States that are said by Colombia to have
encroached on the 200-nautical-mile entitlements of other States are also worth noting. In its
communications sent to the United Nations in response to the submissions of China and the Republic
of Korea to the CLCS, Japan, while objecting to the submissions, emphasized the need for
delimitation between the States concerned. With regard to China, Japan states that
“[t]he distance between the opposite coasts of Japan and the People’s Republic of China
in the area with regard to the submission is less than 400 nautical miles[.] The
delimitation of the continental shelf in this area shall be effected by agreement between
the States concerned in accordance with Article 83 of the United Nations Convention
on the Law of the Sea (hereinafter referred to as ‘the Convention’). It is, thus,
indisputable that the People’s Republic of China cannot unilaterally establish the outer
limits of the continental shelf in this area.” (Note Verbale from the Permanent Mission
of Japan to the United Nations, dated 28 December 2012.)
43. Japan made a similar response to the submission by the Republic of Korea. In its reply to
Japan’s objection, the Republic of Korea stated the following:
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“Nothing in the text of the United Nations Convention on the Law of the Sea
(hereinafter referred to as ‘the Convention’) supports the suggestion that the
establishment of the outer limits of the continental shelf beyond 200 nautical miles in
an area where the distance between States with opposite coasts is less than 400 nautical
miles cannot be accomplished under the provisions of the Convention. The Convention
establishes two distinct bases of entitlement in the continental shelf: (1) distance from
the coast; and (2) the geomorphological criteria stated in paragraph 4 of Article 76.
Neither basis is afforded priority over the other under the Convention. Japan, therefore,
cannot use its entitlement based on the distance criterion to negate Korea’s entitlement
based on geomorphological considerations, or to block the Commission from issuing
recommendations with regard to the existence and limits of the continental shelf in the
East China Sea. Accordingly, the Partial Submission of the Government of the Republic
of Korea to the Commission constitutes a legitimate undertaking in conformity with and
in satisfaction of its obligations under the Convention, as well as the relevant provisions
of the Rules of Procedures and the Scientific and Technical Guidelines of the
Commission.” (Note Verbale from the Permanent Mission of the Republic of Korea to
the United Nations, dated 23 January 2013; emphasis added.)
44. In the case of Somalia, Somalia in its 2014 submission claimed that there was an overlap
between Somali and Yemeni claims as regards the areas of the continental shelf beyond 200 nautical
miles and that the delimitation of the continental shelf between the two countries had not yet been
resolved. It indicated that it was ready to enter into consultation with Yemen with a view to reaching
an agreement or understanding which would allow the Commission to consider and make
recommendations on submissions by each of the two coastal States. In its communication to the
Secretary General, Yemen first objected to the consideration by the CLCS of Somalia’s submission
(Note Verbale from the Permanent Mission of the Republic of Yemen to the United Nations, dated
10 December 2014). Somalia amended its submission in 2015, which resulted in an overlap of its
claim with part of Yemen’s entitlements within 200 nautical miles from the coast of Yemen.
Afterwards, Yemen, while reaffirming that there was no agreement or understanding between the
two States regarding the potential overlap of maritime zones beyond 200 nautical miles, indicated
that
“in the interests of advancing the establishments of maritime limits for itself and its
neighbours in the Northwest Indian Ocean, it proposes to remove its objection to the
Article 76 submission by the Federal Government of Somalia, with immediate effect,
provided that a reciprocal obligation was made by Somalia that it no longer has an
objection to the Commission on the Limits of the Continental Shelf examining the
submissions of The Republic of Yemen.” (Note Verbale from the Permanent Mission
of the Republic of Yemen, dated 7 August 2019.)
Apparently, Yemen has left the matter for delimitation.
45. Kenya initially objected to Somalia’s 2014 submission on the ground that a significant part
of Somalia’s continental shelf beyond 200 nautical miles “is appurtenant to an EEZ that is under
Kenya’s jurisdiction”. Subsequently, in withdrawing its objection, Kenya states that,
“as longs [sic] as the Commission is aware of the area of overlapping claims, and that,
in respect of that area, it gives all due consideration to the submissions made by both
States, the Commission may proceed to make recommendations concerning the outer
limits of the continental shelf off the coasts of Somalia and Kenya” (Note Verbale from
the Permanent Mission of the Republic of Kenya to the United Nations, dated 30 June
2015).
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Kenya’s statement to the CLCS apparently did not suggest that Somalia was not entitled to the
continental shelf but asserted that there was an overlap of entitlements.
46. In the western Caribbean region, Colombia, Costa Rica, Jamaica and Panama, individually
or jointly, opposed Nicaragua’s submission on the ground that Nicaragua’s claim encroached upon
their respective maritime areas. They rejected Nicaragua’s assertion that its submission is “without
prejudice to the delimitation of the continental shelf between Colombia, Costa Rica and Panama”
and reaffirmed their respective positions with respect to Nicaragua’s submission (Communication
from the Ministers for Foreign Affairs of Colombia, Costa Rica and Panama, dated 5 February 2014,
referring to the Note Verbale from the Permanent Mission of Nicaragua to the United Nations, dated
20 December 2013). In denying Nicaragua’s claim, these States objected to the Commission’s
consideration and ruling on Nicaragua’s submission. Colombia in its response dated 5 February 2014
referred to the existing maritime boundaries that it had agreed with its neighbouring States, asserting
that the submarine areas in the Caribbean Sea that Nicaragua claimed in its submission belong to
Colombia under international law. As a non-party to UNCLOS, it dismissed the opposability of
Nicaragua’s submission to Colombia. In none of the above communications did these States
explicitly claim that, as a matter of principle, an extended continental shelf may not extend within
200 nautical miles of another State. Colombia’s claim is primarily based on an argument of
established boundaries and the entitlement of its islands.
47. The above discussion shows that, even though many States parties in their submissions to
the CLCS have refrained from claiming a continental shelf that extends within the 200-nautical-mile
maritime zones of another State, they have done so for various reasons; there is no consistent practice
among those States. The subsequent practice of many of them varies from their position in the
submissions, which seriously weakens the evidentiary value of the submissions (Conclusion 7 of the
ILC Conclusions). Moreover, the other constitutive element for the identification of the alleged
rule — opinio juris — must be determined separately (ILC Conclusions, Conclusion 3, comment 7).
There is no evidence shown in the Judgment that those States parties, when restricting their claim in
the submissions, believed that such restraint was required by a legal obligation or guided by law. The
practice of States, particularly those States whose interests are directly or would likely be affected
by such practice, is neither widespread nor consistent. More importantly, no single case can be found
where a State has explicitly given up its entitlement to an extended continental shelf on the ground
that it believes that its continental shelf may not extend within 200 nautical miles of another State
under international law. In any event, the 51 submissions, which the Court considers as reflecting
“the practice of the vast majority of States parties”, in fact, do not truly reflect the positions of the
States parties on the issue in question. As discussed above, States such as Australia, Indonesia, Papua
New Guinea, France, the Maldives, and others, whose submissions are included in the
51 submissions, clearly take a different view on the entitlement to an extended continental shelf that
encroaches on the 200-nautical-mile limit of another State.
48. Taking into account all the available practice of States and assessing it as a whole, it can
be said that there exists neither a general practice nor opinio juris that denies the entitlement of a
State to an extended continental shelf that extends within 200 nautical miles from the coast of another
State. As many States affirm and have done, when such an overlap of entitlements occurs, the matter
shall be settled through the delimitation process in accordance with the rule reflected in Article 83 of
UNCLOS.
49. The potential impact of the present Judgment on the existing State practice, the stability
and security of treaties, the work of the CLCS and States’ submissions is unpredictable, particularly
in respect of the existing treaties and recommendations of the CLCS that have already accepted the
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entitlement to an extended continental shelf that extends within 200 nautical miles of another State.
The CLCS may thus be placed at a crossroads as to what to do with those “problematic” submissions.
III. NICARAGUA’S SUBMISSIONS ON AN EXTENDED CONTINENTAL SHELF
50. Having considered the state of the law, I am of the view that Nicaragua is entitled to an
extended continental shelf, provided the existence and outer limit of its continental margin is proven.
As a precondition for delimitation, Nicaragua has to first prove that its continental margin overlaps
with the entitlements of Colombia. For that purpose, the technical and scientific evidence adduced
by the Parties must first be examined.
51. Procedurally, the expert reports produced by the Parties were not further examined at the
oral proceedings because of the way in which the hearing was organized. From the written pleadings,
technical and scientific evidence produced by Nicaragua seems to prove that its continental shelf, the
Nicaraguan Rise, extends far enough to reach within 200 nautical miles from the mainland coast of
Colombia. At the same time, however, Colombia’s expert reports, in challenging the information
contained in Nicaragua’s submission to the CLCS with regard to the edge of the natural prolongation
of the Nicaraguan land territory in the Caribbean Sea, also seem technically tenable. Without hearing
from the Parties on those reports and without the assistance of experts appointed by the Court, it is
difficult to assess the weight of each piece of evidence. This underscores the value and
indispensability of the recommendations from the CLCS. In hindsight I believe that, in such a
technically complicated case, it is a necessity for the parties to obtain the recommendations of the
CLCS before proceeding to delimitation.
52. Notwithstanding my serious reservations regarding the reasoning of the Court, there are
two major considerations that led me to vote in favour of the Court’s decision.
53. As a technical matter, the Parties are deeply divided over the scientific and technical facts
of Nicaragua’s extended continental shelf. Nicaragua claims that the Nicaraguan landmass extends
eastwards underwater to form the dominant feature in the southwest Caribbean: the Nicaraguan Rise,
which is said to stretch over 500 nautical miles from the Nicaraguan landmass in the southwest to
Jamaica and Haiti in the northeast. The Nicaraguan Rise, as is shown, is separated from the oceanic
abyssal plain of the Colombian Basin to the south by a linear feature: the Hess Escarpment. Its
northern edge is formed by the Cayman Trough, a deep ocean trench lying to the north of Honduras,
running between Guatemala and the north coast of Jamaica, approximately parallel to the Hess
Escarpment. Nicaragua further asserts that the Nicaraguan Rise is divided into two halves: to the
north the Nicaraguan Rise proper and — separated from it by the Pedro Bank Fracture Zone — the
Lower Nicaraguan Rise to the south. The Nicaraguan Rise is about 150 nautical miles wide
(i.e. north-south) and extends from the land territory of Nicaragua in the west to Haiti in the east.
54. Contesting Nicaragua’s claim, Colombia’s expert reports present the analyses of the
scientific evidence collected from public sources and the Colombian Navy on the natural
prolongation of the sea-bed and subsoil from the Nicaraguan land territory into and under the
Caribbean Sea. The key finding of the reports which is relevant to the present case is that the edge
of the natural prolongation of the Nicaraguan land territory in the Caribbean Sea is not the Hess
Escarpment (the southern limit of the Nicaraguan Rise as assumed by the Applicant), but the Pedro
Bank Escarpment-Providencia Trough Lineament, which separates the southern edge of the
Nicaraguan Rise proper from the Lower Nicaraguan Rise. According to Colombia’s experts, the
scope of Nicaragua’s continental margin is much smaller than Nicaragua’s experts suggest and,
- 21 -
consequently, Nicaragua’s landmass does not extend within 200 nautical miles from the mainland
coast of Colombia.
55. The technical characterization of Nicaragua’s continental margin must be left to scientific
and technical experts. Divergent as they are, the expert reports of the Parties, at the least, inform the
Court of some basic facts that are crucial for the consideration of Nicaragua’s submissions to the
Court for adjudication in the present case.
56. First, the relationship between Nicaragua’s continental margin and Colombia’s mainland
coast remains highly uncertain. Even relying on Nicaragua’s evidence, the outer limit of the Lower
Nicaraguan Rise in the north-east, as defined by Nicaragua, seems overexpansive. The materials
submitted by Nicaragua are not sufficient for the Court to ascertain whether and to what extent
Nicaragua’s continental shelf extends within 200 nautical miles of Colombia.
57. Additionally, the Court has never dealt with such a case where the delimitation involves
the extended continental shelf of only one party. Even assuming that the Nicaraguan Rise is
southbound by the Hess Escarpment, as asserted by Nicaragua, and that Nicaragua’s entitlement is
established and overlaps with Colombia’s entitlements within 200 nautical miles from its mainland
coast, the question nevertheless remains as to what methodology the Court should adopt to delimit
the boundary between the Parties in the area. It seems highly problematic to apply the three-stage
delimitation methodology that is usually used for maritime delimitation within 200 nautical miles;
the relevant considerations for achieving an equitable solution may be quite different in the present
situation.
58. Moreover, the Court should not lose sight of the overall geographical context in which
Nicaragua’s purported continental shelf is located. As is shown on the maps presented by the Parties,
situated on the Nicaraguan Rise, alongside Nicaragua, are Colombia’s Archipelago of San Andrés,
Providencia and Santa Catalina, Jamaica and Haiti. In the western Caribbean, there is Jamaica to the
north and Panama to the south. Notwithstanding the existing delimitation treaties between each of
these States and Colombia, which are not opposable to Nicaragua, res inter alios acta, the
entitlements of those States to a continental shelf within 200 nautical miles would likely overlap with
any extended continental shelf Nicaragua may have. Therefore, it is doubtful that any extended
continental shelf that Nicaragua might have established could be given its full effect to the extent
that Nicaragua claims. As between the Parties, it is Colombia’s islands that are situated in the middle
of the mainland coasts of the two States that prove crucial for the delimitation between the Parties.
59. In the 2012 Judgment, the Court clearly did not delimit the maritime area eastward beyond
the relevant area as identified for the delimitation of the maritime boundary between the Parties
within 200 nautical miles from the mainland coast of Nicaragua (Territorial and Maritime Dispute
(Nicaragua v. Colombia), ICJ Reports 2012 (II), p. 683, para. 159). In rejecting Nicaragua’s
proposal to draw a series of enclaves around each of Colombia’s islands, the Court underscored the
requirement not to produce cut-off effect in the delimitation. It considered, in particular, that
“[e]ven if each island were to be given an enclave of 12 nautical miles, and not
3 nautical miles as suggested by Nicaragua, the effect would be to cut off Colombia
from the substantial areas to the east of the principal islands, where those islands
generate an entitlement to a continental shelf and exclusive economic zone. In addition,
the Nicaraguan proposal would produce a disorderly pattern of several distinct
Colombian enclaves within a maritime space which otherwise pertained to Nicaragua
with unfortunate consequences for the orderly management of maritime resources,
- 22 -
policing and the public order of the oceans in general, all of which would be better
served by a simpler and more coherent division of the relevant area.” (Territorial and
Maritime Dispute (Nicaragua v. Colombia), ICJ Reports 2012 (II), p. 708, para. 230.)
The Court, by implication, recognized that Colombia’s islands are entitled to their continental shelves
under customary international law. In the present case, should Nicaragua’s second and third
submissions — similar to the request Nicaragua had made in the Territorial and Maritime
Dispute case — be upheld, it would produce a cut-off effect between the islands and the
mainland of Colombia. Indeed, it would not be conducive to an orderly management of the maritime
area and a coherent relationship among the coastal States in the western Caribbean. As Colombia’s
islands in the east face the mainland coast of Colombia, their entitlements to an exclusive economic
zone and continental shelf should be given full effect. Furthermore, they are situated on the landmass
constituting part of the continental shelf claimed by Nicaragua. Under the circumstances, it is
questionable whether Nicaragua could still make a good case for its claim.
60. Based on the foregoing considerations, I come to the conclusion that Nicaragua’s
submissions should not be upheld.
(Signed) XUE Hanqin.
___________

Bilingual Content

482
SEPARATE OPINION OF JUDGE XUE
table of contents
Paragraphs
I. Procedural Fairness for the Good Administration of
Justice 2-9
II. Substantive Issues in the Present Case 10-49
A. Continental shelf under customary international law as
reflected in Article 76
B. Relationship between the régimes of the continental shelf and
of the exclusive economic zone
C. State practice with regard to CLCS submissions
11-19
20-36
37-49
III. Nicaragua’s Submissions on an Extended Continental Shelf 50-60
1. I have voted in favour of the operative paragraph of the Judgment but on
entirely different legal grounds. I have serious reservations about the Court’s
findings on the applicable law in the present case. The legal ramifications it
may exert on the régime of continental shelf are hard to tell. I am obligated
to place my position on the record.
I. Procedural Fairness for the Good
Administration of Justice
2. My reservation about the procedural fairness in the organization of oral
proceedings has been largely reflected in the joint declaration appended to
the Order of 4 October 2022 in the present case (Question of the Delimitation
of the Continental Shelf between Nicaragua and Colombia beyond
200 Nautical Miles from the Nicaraguan Coast (Nicaragua v. Colombia),
Order of 4 October 2022, I.C.J. Reports 2022 (II), joint declaration of
Judges Tomka, Xue, Robinson, Nolte and Judge ad hoc Skotnikov, p. 566).
With this final decision settling the case, the oral proceedings on the merits
were closed and, consequently, the Parties did not have an oral hearing to
make their final arguments on all the issues that still divided them and to
submit their final submissions to the Court. Procedurally, this practice is
unprecedented in the Court’s judicial history.
482
OPINION INDIVIDUELLE DE Mme LA JUGE XUE
[Traduction]
table des matières
Paragraphes
I. L’équité procédurale pour une bonne administration de la
justice 2-9
II. Les questions de fond dans la présente espèce 10-49
A. Le plateau continental au sens du droit international coutumier
tel que reflété à l’article 76
B. La relation entre le régime du plateau continental et celui
de la zone économique exclusive
C. La pratique des États devant la Commission des limites
11-19
20-36
37-49
III. La demande de plateau continental étendu du Nicaragua 50-60
1. J’ai voté en faveur du dispositif de l’arrêt mais sur le fondement de motifs
juridiques entièrement différents. J’ai de sérieuses réserves au sujet des
conclusions de la Cour concernant le droit applicable en la présente affaire.
Les conséquences juridiques que cela pourrait avoir pour le régime du plateau
continental sont difficiles à cerner. Je me dois d’exprimer ma position.
I. L’équité procédurale pour une bonne
administration de la justice
2. Mes réserves quant à l’équité de la procédure dans la tenue des audiences
ont déjà été exprimées en détail dans la déclaration commune jointe à
l’ordonnance rendue le 4 octobre 2022 en l’instance (Question de la délimitation
du plateau continental entre le Nicaragua et la Colombie au-delà
de 200 milles marins de la côte nicaraguayenne (Nicaragua c. Colombie),
ordonnance du 4 octobre 2022, C.I.J. Recueil 2022 (II), déclaration commune
de M. le juge Tomka, Mme la juge Xue, MM. les juges Robinson et
Nolte, ainsi que M. le juge ad hoc Skotnikov, p. 566). Avec le présent arrêt
qui règle définitivement le différend, la procédure orale sur le fond est close
et les Parties n’ont donc pas pu exposer à l’audience leurs arguments finaux
sur toutes les questions qui les divisaient encore, ni présenter leurs conclusions
finales à la Cour. Du point de vue procédural, cette façon de faire est
sans précédent dans l’histoire judiciaire de la Cour.
483 delimitation of the continental shelf (sep. op. xue)
3. According to Article 48 of the Statute, the Court shall make orders for
the conduct of the case and decide the form and time in which each party
must conclude its arguments. This power, however, must be exercised in
accordance with the principle of juridical propriety for the good administration
of justice. Article 31 of the Rules of Court provides that “[i]n every case
submitted to the Court, the President shall ascertain the views of the parties
with regard to questions of procedure”. Procedurally, the Court must ensure
that each party is free to choose and follow its own judicial strategy and to
fully develop all its arguments. In this regard, the Court should exercise
great caution when controlling the oral proceedings so as to avoid jeopardizing
the rights of the parties (Question of the Delimitation of the Continental
Shelf between Nicaragua and Colombia beyond 200 Nautical Miles from
the Nicaraguan Coast (Nicaragua v. Colombia), Order of 4 October 2022,
I.C.J. Reports 2022 (II), joint declaration of Judges Tomka, Xue, Robinson,
Nolte and Judge ad hoc Skotnikov, p. 569, para. 11, n. 3, citing Mohammed
Bedjaoui, “The ‘Manufacture’ of Judgments at the International Court of
Justice”, Pace Yearbook of International Law, 1991, Vol. 3, p. 44; Eduardo
Jiménez de Aréchaga, “The Amendments to the Rules of Procedure of the
International Court of Justice”, American Journal of International Law,
1973, Vol. 67 (1), p. 7).
4. In its final written pleadings, Nicaragua has made three submissions.
The first submission concerns maritime delimitation between the continental
shelf beyond 200 nautical miles (also referred to as the “extended
continental shelf”) as claimed by Nicaragua and Colombia’s maritime area
within 200 nautical miles from Colombia’s mainland baselines. The second
and third submissions relate to the maritime entitlements of Colombia’s
maritime features that may overlap with Nicaragua’s entitlement to an
extended continental shelf. Apparently, Nicaragua’s submissions concern
both maritime entitlements of the Parties and delimitation. The legal questions
posed by the Court in the 4 October 2022 Order primarily address the
issue of entitlement. Without hearing the Parties on all the issues, both in law
and in fact, and without making the entire case file accessible to the public,
the judicial process did not fully run its course. This is particularly questionable
when the Applicant has specifically requested the Court to proceed to a
hearing on the merits.
5. Procedurally, even supposing that the answers to the legal questions
were decisive for the resolution of the whole case, the present approach
adopted by the Court at this phase should still be called into question. As the
Applicant indicated, the legal questions posed by the Court had already been
substantially argued by the Parties in the course of the written proceedings
of this case and during the Territorial and Maritime Dispute (Nicaragua v.
Colombia) case.
délimitation du plateau continental (op. ind. xue) 483
3. Conformément à l’article 48 de son Statut, la Cour rend des ordonnances
pour la direction du procès et détermine les formes et délais dans lesquels
chaque partie doit finalement conclure. Elle doit cependant exercer ce pouvoir
conformément au principe de la correction juridique, aux fins d’une
bonne administration de la justice. L’article 31 du Règlement dispose que,
« [d]ans toute affaire soumise à la Cour, le Président se renseigne auprès des
parties sur les questions de procédure ». Du point de vue procédural, la Cour
doit s’assurer que chaque partie est libre de choisir sa propre stratégie
judiciaire et peut développer pleinement tous ses arguments. À cet égard,
elle doit faire preuve d’une grande prudence lorsqu’il s’agit d’encadrer la
procédure orale, afin de ne pas compromettre les droits des parties (Question
de la délimitation du plateau continental entre le Nicaragua et la Colombie
au-delà de 200 milles marins de la côte nicaraguayenne (Nicaragua
c. Colombie), ordonnance du 4 octobre 2022, C.I.J. Recueil 2022 (II), déclaration
commune de M. le juge Tomka, Mme la juge Xue, MM. les juges
Robinson et Nolte, ainsi que M. le juge ad hoc Skotnikov, p. 569, par. 11, n. 3,
renvoyant à Mohammed Bedjaoui, « La “fabrication” des arrêts de la Cour
internationale de Justice », dans Le droit international au service de la paix,
de la justice et du développement : mélanges Michel Virally, 1991, Paris,
Pedone, p. 95 ; Eduardo Jiménez de Aréchaga, « The Amendments to the
Rules of Procedure of the International Court of Justice », American Journal
of International Law, 1973, vol. 67, no 1, p. 7).
4. Dans ses dernières écritures, le Nicaragua formulait trois demandes. La
première concernait la délimitation maritime entre le plateau continental
au-delà de 200 milles marins (également appelé le « plateau continental
étendu ») qu’il revendique et la zone maritime à laquelle la Colombie a droit
sur 200 milles marins à partir des lignes de base de sa côte continentale. Les
deuxième et troisième demandes concernaient les espaces maritimes générés
par certaines formations maritimes de la Colombie qui pourraient
chevaucher le plateau continental étendu revendiqué par le Nicaragua. À
l’évidence, les prétentions du demandeur ont trait à la fois aux droits des Parties
à des espaces maritimes et à la délimitation. Les questions juridiques
posées par la Cour dans son ordonnance du 4 octobre 2022 portent principalement
sur la question des droits. Les Parties n’ayant pas été entendues sur
tous les points, de fait comme de droit, qui se posent en l’espèce, et le public
n’ayant pas eu accès à la totalité du dossier, la procédure judiciaire n’a pas été
suivie jusqu’au bout. C’est d’autant plus contestable que le Nicaragua avait
spécifiquement prié la Cour de tenir des audiences sur le fond.
5. Du point de vue procédural, même à supposer que les réponses aux
questions juridiques posées par la Cour fussent décisives pour le règlement
de l’affaire dans son ensemble, l’approche suivie par la Cour à cette étape de
la procédure est néanmoins sujette à caution. Comme l’a relevé le demandeur,
ces questions juridiques avaient déjà été amplement débattues par les
Parties lors de la procédure écrite en la présente affaire, ainsi que dans celle
du Différend territorial et maritime (Nicaragua c. Colombie).
484 delimitation of the continental shelf (sep. op. xue)
6. The first legal question posed by the Court initially arose from Nicaragua’s
submission I (3) in the Territorial and Maritime Dispute (Nicaragua v.
Colombia) case, where Nicaragua requested the Court to define “a continental
shelf boundary dividing by equal parts the overlapping entitlements to a
continental shelf of both Parties”, which means that Nicaragua’s claim to a
continental shelf extends beyond 200 nautical miles, as the distance between
the mainland coasts of the Parties extends more than 400 nautical miles
(Judgment, I.C.J. Reports 2012 (II) (hereinafter the “2012 Judgment”),
p. 636, para. 17). The Court rejected Nicaragua’s request for the delimitation
of its extended continental shelf with Colombia’s maritime entitlements on
the ground that Nicaragua had not established that it has a continental margin
that extends far enough to overlap with Colombia’s 200-nautical-mile
entitlement to the continental shelf, measured from Colombia’s mainland
coast. The Court stated that it was not in a position to delimit the continental
shelf boundary between Nicaragua and Colombia, as requested by Nicaragua,
even using the general formulation proposed by it (ibid., p. 669.
para. 129). In this regard, the Court especially mentioned that it saw no
need to address the issue raised by the Parties as to whether a delimitation of
overlapping entitlements which involves an extended continental shelf of
one State can affect a 200-nautical-mile entitlement to the continental shelf
of another State (ibid., pp. 669-670, paras. 129-130), a legal question that the
Court now considers has been answered by customary international law.
7. Moreover, during the oral proceedings in that case, Judge Bennouna
posed the following questions to the Parties:
— “Is the legal régime of the continental shelf for the portion located
within the 200-nautical-mile limit different from that for the portion
located beyond this limit?”
— “Can the rules laid down in Article 76 of the 1982 United Nations
Convention on the Law of the Sea concerning the determination of
the outer limit of the continental shelf beyond 200 nautical miles
today be considered as rules of customary international law?”
In answering Judge Bennouna’s questions, the Parties went some way in
answering the first question posed by the Court in the Order of 4 October
2022 and gave their views on the criteria under customary international
law for the determination of the limit of the continental shelf beyond
200 nautical miles.
8. At the preliminary objections phase in the present case, Colombia contended
that Nicaragua’s first submission was a “reincarnation” of Nicaragua’s
claim contained in its final submission I (3) in the Territorial and Maritime
Dispute case, in so far as it concerned delimitation of extended continental
shelf. It argued that, by virtue of res judicata, the Court was prevented from
délimitation du plateau continental (op. ind. xue) 484
6. La première question juridique de la Cour découlait initialement du
point I. 3) des conclusions finales du Nicaragua en l’affaire du Différend territorial
et maritime (Nicaragua c. Colombie), dans lesquelles le demandeur
priait la Cour de tracer « une limite opérant une division par parts égales de
la zone du plateau continental où les droits des deux Parties sur celui-ci se
chevauchent », ce qui signifie que le plateau continental qu’il revendique
s’étend au-delà de 200 milles marins, la distance entre les côtes continentales
des Parties dépassant 400 milles marins (arrêt, C.I.J. Recueil 2012 (II)
(ci-après l’« arrêt de 2012 »), p. 636, par. 17). La Cour avait rejeté cette
demande, refusant de procéder à la délimitation entre le plateau continental
étendu du Nicaragua et les espaces maritimes de la Colombie au motif que le
Nicaragua n’avait pas établi que sa marge continentale s’étendait suffisamment
loin pour empiéter sur le plateau continental auquel la Colombie a droit
sur 200 milles marins à partir de sa côte continentale. La Cour avait déclaré
n’être pas en mesure de tracer la frontière entre les plateaux continentaux
respectifs du Nicaragua et de la Colombie, comme l’en priait le demandeur,
même au moyen de la formulation générale proposée par ce dernier (ibid.,
p. 669, par. 129). À ce propos, elle avait dit en particulier qu’il n’y avait pas
lieu d’examiner la question — soulevée par les Parties — de savoir si la délimitation
d’une zone où se chevauchent le droit d’un État à un plateau
continental étendu et le droit d’un autre État à un plateau continental de
200 milles marins est susceptible de porter atteinte au droit de ce dernier
(ibid., p. 669-670, par. 129-130), une question juridique dont la Cour estime
à présent qu’elle trouve réponse dans le droit international coutumier.
7. En outre, au cours des audiences en cette affaire-là, le juge Bennouna
avait posé les deux questions suivantes aux Parties :
— « Le régime juridique du plateau continental est-il différent pour la
portion de celui-ci qui se situe en deçà de la limite des 200 milles
marins et pour la portion située au-delà de cette limite ? »
— « Les règles posées à l’article 76 de la convention des Nations Unies
de 1982 sur le droit de la mer, pour la détermination de la limite extérieure
du plateau continental au-delà des 200 milles marins,
peuvent-elles être considérées aujourd’hui comme ayant le caractère
de règles de droit international coutumier ? »
Dans leurs réponses à ces questions, les Parties répondaient déjà partiellement
à la première question qui leur serait posée par la Cour dans l’ordonnance
du 4 octobre 2022 et exposaient leur point de vue sur les critères établis en
droit international coutumier pour fixer la limite d’un plateau continental
au-delà de 200 milles marins.
8. Au stade des exceptions préliminaires en la présente instance, la Colombie
a affirmé que la première demande du Nicaragua en l’espèce était une
« nouvelle version » de celle qui était contenue au point I. 3) de ses conclusions
finales en l’affaire du Différend territorial et maritime, en ce qu’elle
concernait la délimitation d’un plateau continental étendu. La Colombie esti485
delimitation of the continental shelf (sep. op. xue)
entertaining it in the present case. The Court rejected Colombia’s objections,
including its claim based on res judicata, and upheld the admissibility of
Nicaragua’s first submission. During the written proceedings, the Parties
significantly developed their arguments on Nicaragua’s entitlement to an
extended continental shelf and its relationship with Colombia’s entitlements
within 200 nautical miles.
9. From a procedural point of view, there seems to be no sound reason for
the Court to depart from its established practice by holding an oral proceeding
to hear the views of the Parties only on two legal questions. The Parties
could have addressed them together with the factual and other legal aspects
of the case during the oral proceedings on the merits. If the settlement of the
dispute between the Parties on Nicaragua’s entitlement to an extended continental
shelf indeed hinges entirely on the answers to the legal questions, as
recalled above, the matter should have been resolved much earlier for the
sake of judicial economy. As a judicial organ, the Court is supposed to know
the law  iura novit curia  and apply it to settle a dispute whenever it is
called for. If the Court considers that, under customary international law,
maritime entitlements within 200 nautical miles of one State take precedence
over an extended continental shelf of another State, it should have
decided, either in the 2012 Judgment in the Territorial and Maritime Dispute
case or in the Judgment of 17 March 2016 on preliminary objections in the
present case (hereinafter the “2016 Judgment”), that, by virtue of customary
international law, Nicaragua’s claim of an extended continental shelf should
be rejected outright because Nicaragua is not entitled to such a claim and
consequently no issue of delimitation arises between the Parties. The dispute
would thus have been settled there. Having unduly prolonged the judicial
process and having left unexamined all the technical and scientific evidence
submitted by the Parties, the Court’s approach, for whatever reason, cannot
be deemed in conformity with the principles of judicial propriety and has
doubtfully facilitated judicial economy.
II. Substantive Issues in the Present Case
10. I agree with the majority that the negotiation and conclusion of the
United Nations Convention on the Law of the Sea (hereinafter “UNCLOS”)
has, to a large extent, codified and contributed to the progressive development
of customary international law of the sea. However, I do not share the
reasoning given in the Judgment on the contemporary régime of the continental
shelf. The legal issue before the Court ultimately boils down to a
question that often arises in continental shelf delimitation, namely, the relationship
between the extended continental shelf of one State and maritime
entitlements within 200 nautical miles from the baselines of another State. It
délimitation du plateau continental (op. ind. xue) 485
mait que, en vertu du principe de la chose jugée, la Cour ne pouvait pas
connaître de cette demande dans la présente espèce. La Cour a rejeté les
exceptions préliminaires soulevées par la Colombie, y compris celle qui était
fondée sur le principe de la chose jugée, et a déclaré recevable la première
demande du Nicaragua. Au cours de la procédure écrite, les Parties ont substantiellement
développé leurs arguments en ce qui concerne le droit du
Nicaragua à un plateau continental étendu et la relation entre ce droit et celui
de la Colombie à un espace maritime de 200 milles marins.
9. Du point de vue procédural, la Cour ne semblait avoir aucune raison
valable de s’écarter de sa pratique établie pour entendre les vues des Parties
sur deux questions juridiques uniquement. Les Parties auraient pu traiter ces
questions en même temps que les aspects factuels et les autres points de droit
de l’affaire, au cours de la procédure orale sur le fond. Si, comme il a été dit
précédemment, le règlement du différend les opposant sur le droit du Nicaragua
à un plateau continental étendu dépendait entièrement des réponses
aux deux questions juridiques, il aurait fallu régler cela bien plus tôt, dans
l’intérêt de l’économie judiciaire. En tant qu’organe judiciaire, la Cour est
censée connaître le droit  iura novit curia  et l’appliquer pour régler un
différend chaque fois que c’est nécessaire. Si elle considère que, en droit
international coutumier, le droit d’un État à un espace maritime de 200 milles
marins prime le droit d’un autre État à un plateau continental étendu, elle
aurait dû conclure, soit dans l’arrêt de 2012, soit dans celui du 17 mars 2016
sur les exceptions préliminaires en la présente affaire, que, en vertu de ce
même droit international coutumier, le Nicaragua était d’entrée de jeu
débouté de sa demande au motif qu’il ne pouvait pas prétendre à un plateau
continental étendu et que, par conséquent, aucune question de délimitation
ne se posait entre les Parties. Le différend aurait alors été réglé à ce stade. En
prolongeant indûment la procédure judiciaire et en n’examinant aucun des
éléments de preuve techniques et scientifiques présentés par les Parties, la
Cour a suivi une approche dont on ne peut en aucun cas dire qu’elle ait été
conforme au principe de la correction juridique ni, probablement, qu’elle ait
servi l’économie judiciaire.
II. Les questions de fond dans la présente espèce
10. Je partage l’avis de la majorité que la négociation et la conclusion de la
convention des Nations Unies sur le droit de la mer (ci-après la « CNUDM »)
a, dans une large mesure, codifié le droit international coutumier de la mer et
contribué à son développement progressif. Cependant, je ne souscris pas au
raisonnement exposé dans l’arrêt sur le régime contemporain du plateau continental.
La question juridique dont la Cour est saisie se résume en fin de compte
à une question qui se pose fréquemment dans les délimitations de plateau
continental, celle de la relation entre le plateau continental étendu d’un État et
les espaces maritimes auxquels un autre État a droit sur 200 milles marins à
486 delimitation of the continental shelf (sep. op. xue)
bears on the fundamental concept of natural prolongation in contemporary
customary international law and the “package deal” that was negotiated and
eventually worked out at the Third United Nations Conference on the Law of
the Sea (hereinafter the “Law of the Sea Conference”). The reasoning of the
Judgment on the current state of the law, in my view, is neither persuasive
nor reflective of general State practice and opinio juris.
A. Continental Shelf under Customary International Law
as Reflected in Article 76
11. The first question that the Court posed to the Parties in the Order of
4 October 2022 (hereinafter the “first question”) reads as follows:
“Under customary international law, may a State’s entitlement to a
continental shelf beyond 200 nautical miles from the baselines from
which the breadth of its territorial sea is measured extend within
200 nautical miles from the baselines of another State?”
This question basically asks an issue of entitlement on the basis of the relationship
between two criteria as set forth in Article 76, paragraph 1, of
UNCLOS. If the two criteria are of equal applicability, Nicaragua may be
entitled to an extended continental shelf which overlaps with Colombia’s
entitlements within 200 nautical miles, provided its physical existence is
established. The case then calls for delimitation. If the answer to the question
is in the negative, it means that the distance criterion takes precedence
over natural prolongation. Colombia’s 200-nautical-mile entitlements prevail
over Nicaragua’s claim; Nicaragua is not entitled to an extended
continental shelf that extends within 200 nautical miles of Colombia. Consequently,
there is no issue of delimitation between the Parties. The answer to
the first question apparently has to be found in customary international law.
12. Under customary international law, the continental shelf régime originates
from the concept of natural prolongation. The doctrine of the
continental shelf was first recalled by the Court in the North Sea Continental
Shelf cases (North Sea Continental Shelf (Federal Republic of Germany/
Denmark; Federal Republic of Germany/Netherlands), Judgment, I.C.J.
Reports 1969, pp. 32-33, para. 47), in which the Court considered that the
essential basis of the continental shelf is the extended sovereign rights of the
coastal State over the natural prolongation or continuation of its land territory
under the sea. Such rights exist ipso facto and ab initio (ibid., p. 22,
para. 19). This pronouncement was reiterated by the Court in subsequent
cases. In the Tunisia/Libyan Arab Jamahiriya case, for example, the Court
stated that
délimitation du plateau continental (op. ind. xue) 486
partir de ses lignes de base. Cette question se rapporte à la notion fondamentale
de prolongement naturel en droit international coutumier contemporain et
au compromis global (package deal) qui fut négocié et finalement atteint à la
troisième conférence des Nations Unies sur le droit de la mer (ci-après la
« conférence sur le droit de la mer »). Je suis d’avis que le raisonnement qui est
exposé dans l’arrêt sur l’état actuel du droit n’est pas convaincant et ne
concorde pas avec la pratique générale des États et l’opinio juris.
A. Le plateau continental au sens du droit international coutumier
tel que reflété à l’article 76
11. La première question que la Cour a posée aux Parties dans l’ordonnance
du 4 octobre 2022 (ci-après la « première question ») était ainsi
rédigée :
« En droit international coutumier, le droit d’un État à un plateau
continental au-delà de 200 milles marins des lignes de base à partir desquelles
est mesurée la largeur de sa mer territoriale peut-il s’étendre à
des espaces maritimes en deçà de 200 milles marins des lignes de base
d’un autre État ? »
Cette question pose fondamentalement celle de l’existence d’un droit au
regard de la relation entre les deux critères énoncés au paragraphe 1 de l’article
76 de la CNUDM. Si les deux critères s’appliquent de manière égale, le
Nicaragua peut avoir droit à un plateau continental étendu chevauchant les
espaces maritimes auxquels la Colombie a droit sur une distance de
200 milles marins, pour autant qu’en soit établie l’existence physique. Cette
situation appelle alors une délimitation. S’il n’y a pas égalité d’applicabilité
entre les critères, alors celui de la distance prime celui du prolongement
naturel. Le droit de la Colombie à des espaces maritimes de 200 milles
marins prévaut sur la revendication du Nicaragua ; celui-ci n’a pas droit à un
plateau continental étendu se prolongeant à moins de 200 milles marins du
territoire colombien. Dans cette situation-là, il n’y a pas de problème de délimitation
entre les Parties. La réponse à la première question de la Cour se
trouve manifestement dans le droit international coutumier.
12. En droit international coutumier, le régime du plateau continental
trouve son origine dans la notion de prolongement naturel. La Cour a rappelé
pour la première fois la doctrine du plateau continental dans les affaires du
Plateau continental de la mer du Nord (Plateau continental de la mer du
Nord (République fédérale d’Allemagne/Danemark ; République fédérale
d’Allemagne/Pays-Bas), arrêt, C.I.J. Recueil 1969, p. 32-33, par. 47), considérant
que cette notion repose fondamentalement sur les droits souverains
étendus que possède l’État côtier sur le prolongement naturel ou l’extension
de son territoire terrestre sous la mer, droits qui existent ipso facto et ab
initio (ibid., p. 22, par. 19). La Cour a réaffirmé cette conclusion par la suite.
Dans l’affaire Tunisie/Jamahiriya arabe libyenne, par exemple, elle a dit ce
qui suit :
487 delimitation of the continental shelf (sep. op. xue)
“[t]he concept of natural prolongation . . . was and remains a concept to
be examined within the context of customary law and State practice.
While the term ‘natural prolongation’ may have been novel in 1969, the
idea to which it gave expression was already a part of existing customary
law as the basis of the title of the coastal State.” (Continental Shelf
(Tunisia/Libyan Arab Jamahiriya), Judgment, I.C.J. Reports 1982, p. 46,
para. 43.)
13. Admittedly, contemporary customary international law on the definition
of the continental shelf was much influenced by the negotiations of the
Law of the Sea Conference that lasted for nine years. Not long after the
Court delivered its Judgment in the North Sea Continental Shelf cases, the
United Nations General Assembly adopted a resolution in which it was
stated
“that the definition of the continental shelf contained in the Convention
on the Continental Shelf of . . . 1958 does not define with sufficient precision
the limits of the area over which a coastal State exercises sovereign
rights for the purpose of exploration and exploitation of natural
resources, and that customary international law on the subject is inconclusive”
(resolution 2574 (XXIV) of 15 December 1969, adopted with
65 votes in favour, 12 against, and 30 abstentions; emphasis added).
This resolution was adopted against the backdrop of the upcoming negotiations
on the law of the sea and growing concern over the prospects of deep
seabed mining. The definition found in Article 1 of the 1958 Convention did
not provide a definitive limit of continental margin, leaving it open to technical
exploitability. The relevant article reads as follows:
“For the purpose of these articles, the term ‘continental shelf’ is used
as referring (a) to the seabed and subsoil of the submarine areas adjacent
to the coast but outside the area of the territorial sea, to a depth of
200 metres or, beyond that limit, to where the depth of the superjacent
waters admits of the exploitation of the natural resources of the said
areas; (b) to the seabed and subsoil of similar submarine areas adjacent
to the coasts of islands.”
Apparently, when the United Nations General Assembly disapproved of this
definition as imprecise, the focus of its attention was on the limits of the continental
shelf but not its foundation; it was feared that by recognizing an
exploitability criterion, coastal States may, with the continuous advancement
of technology and science, extend their claim unrestrictedly, thus
encroaching upon the common area of the deep seabed and its resources,
which were subsequently proclaimed as the “common heritage of mankind”
at the Law of the Sea Conference. It was this common interest that eventudélimitation
du plateau continental (op. ind. xue) 487
« [l]a notion de prolongement naturel est et demeure … une notion à examiner
dans le contexte du droit coutumier et de la pratique des États. Si
l’expression “prolongement naturel” était inédite en 1969, l’idée qu’elle
visait à traduire faisait déjà partie du droit coutumier existant en tant que
fondement du titre de l’État riverain. » (Plateau continental (Tunisie/
Jamahiriya arabe libyenne), arrêt, C.I.J. Recueil 1982, p. 46, par. 43.)
13. Certes, la définition du plateau continental que donne le droit international
coutumier contemporain a été très influencée par les négociations de
la conférence sur le droit de la mer, qui ont duré neuf ans. Peu après que la
Cour eut statué dans les affaires du Plateau continental de la mer du Nord,
l’Assemblée générale des Nations Unies a adopté une résolution dans laquelle
il est relevé que
« la définition du plateau continental contenue dans la Convention sur le
plateau continental d[e] 1958 n’indique pas avec suffisamment de précision
les limites de la zone sur laquelle un État riverain exerce des droits
souverains aux fins de l’exploration et de l’exploitation des ressources
naturelles, et que le droit international coutumier en la matière ne
tranche pas cette question » (résolution 2574 (XXIV) du 15 décembre
1969, adoptée par 65 voix contre 12, avec 30 abstentions ; les italiques
sont de moi).
Cette résolution fut adoptée avec en toile de fond les négociations à venir sur
le droit de la mer et une inquiétude croissante face aux perspectives d’exploitation
des grands fonds marins. La définition figurant à l’article premier de
la convention de 1958 ne fixait pas de limite définitive à la marge continentale,
ouvrant la porte à l’exploitation technique. Cet article se lit comme suit :
« Aux fins des présents articles, l’expression « plateau continental » est
utilisée pour désigner : a) le lit de la mer et le sous-sol des régions
sous-marines adjacentes aux côtes, mais situées en dehors de la mer territoriale,
jusqu’à une profondeur de 200 mètres ou, au-delà de cette
limite, jusqu’au point où la profondeur des eaux su[s-]jacentes permet
l’exploitation des ressources naturelles desdites régions ; et b) le lit de la
mer et le sous-sol des régions sous-marines analogues qui sont adjacentes
aux côtes des îles. »
À l’évidence, lorsqu’elle a jugé cette définition trop imprécise, l’Assemblée
générale se référait surtout aux limites, et non aux fondements, du plateau
continental ; la crainte était que, avec la reconnaissance d’un critère d’exploitabilité,
les États côtiers puissent, grâce aux progrès technologiques et
scientifiques continus, étendre sans restriction leurs revendications, empiétant
ainsi sur l’espace commun des grands fonds marins et de leurs ressources,
lequel serait par la suite proclamé «patrimoine commun de l’humanité» à la
conférence sur le droit de la mer. C’est cet intérêt commun qui a finalement
488 delimitation of the continental shelf (sep. op. xue)
ally led to the new regulation of the continental shelf régime under Part VI
of UNCLOS.
14. The outcome of the negotiations on Part VI of UNCLOS is a balanced
solution between the individual interest of coastal States and the common
interest of the international community. From the text of Part VI, it is not
difficult to observe that the fundamental basis of the continental shelf régime
remains intact under the “package deal”; natural prolongation as the physical
criterion for the determination of the continental shelf is not replaced by a
distance criterion, the criterion applicable to the régime of the exclusive economic
zone. There is no basis in customary international law to suggest that
restrictions imposed on the extent and use of the continental shelf beyond
200 nautical miles imply that the continental shelf is now under two régimes:
the régime of continental shelf within 200 nautical miles and the régime of
the extended continental shelf. Either based on the natural prolongation of its
land territory or a distance of 200 nautical miles, every coastal State is entitled
to a single continental shelf; the substantive rights of the coastal State in
the continental shelf within and beyond 200 nautical miles from the baselines
are generally the same, which is affirmed by subsequent judicial and
arbitral decisions, including the present Judgment (Delimitation of the Maritime
Boundary in the Bay of Bengal (Bangladesh/Myanmar), Judgment,
ITLOS Reports 2012, p. 96, para. 361; Bay of Bengal Maritime Boundary
Arbitration (Bangladesh v. India), Award of 7 July 2014, United Nations,
Reports of International Arbitral Awards (RIAA), Vol. XXXII, p. 38,
para. 77; the present Judgment, para. 75).
15. The equal relationship between the two criteria can be further observed
from the text of Article 76, paragraph 1, which is considered by the Court as
reflective of customary international law (Territorial and Maritime Dispute
(Nicaragua v. Colombia), Judgment, I.C.J. Reports 2012 (II), p. 666,
para. 118).
Article 76, paragraph 1, provides:
“The continental shelf of a coastal State comprises the sea-bed and
subsoil of the submarine areas that extend beyond its territorial sea
throughout the natural prolongation of its land territory to the outer edge
of the continental margin, or to a distance of 200 nautical miles from the
baselines from which the breadth of the territorial sea is measured where
the outer edge of the continental margin does not extend up to that
distance.”
By virtue of this provision, a distance criterion is added alongside the natural
prolongation criterion to the definition of the continental shelf. A coastal
State whose continental margin does not extend up to 200 nautical miles
may extend its entitlement to 200 nautical miles, irrespective of geological
and other geophysical conditions. This entitlement provision, by its ordinary
meaning, nowhere indicates that the two criteria apply respectively to two
délimitation du plateau continental (op. ind. xue) 488
conduit à la nouvelle réglementation que constitue le régime du plateau
continental défini à la partie VI de la CNUDM.
14. La solution à laquelle ont abouti les négociations sur la partie VI de la
CNUDM est un juste équilibre entre les intérêts individuels des États côtiers
et l’intérêt commun de la communauté internationale. À la lecture du texte
de cette partie VI, il n’est pas difficile de voir que la base fondamentale du
régime du plateau continental reste intacte dans le compromis global (package
deal) ; le prolongement naturel, en tant que critère physique pour la
détermination du plateau continental, n’est pas remplacé par un critère de
distance, qui est celui applicable au régime de la zone économique exclusive.
Rien dans le droit international coutumier ne donne à croire que les restrictions
à l’extension et à l’utilisation du plateau continental au-delà de
200 milles marins signifient qu’il existerait désormais deux régimes : celui
du plateau continental limité à 200 milles marins et celui du plateau continental
étendu. Que ce soit sur la base du prolongement naturel de son
territoire ou du critère de la distance de 200 milles marins, chaque État
côtier a droit à un seul plateau continental ; ses droits substantiels sur le plateau
continental en deçà et au-delà de 200 milles marins de ses lignes de
base sont généralement les mêmes, ainsi que l’ont confirmé des décisions
judiciaires et des sentences arbitrales, y compris le présent arrêt (Délimitation
de la frontière maritime dans le golfe du Bengale (Bangladesh/
Myanmar), arrêt, TIDM Recueil 2012, p. 96, par. 361 ; Arbitrage concernant
la frontière maritime dans le golfe du Bengale (Bangladesh c. Inde), sentence
du 7 juillet 2014, Nations Unies, Recueil des sentences arbitrales
(RSA), vol. XXXII, p. 38, par. 77 ; arrêt en l’espèce, par. 75).
15. La relation d’égalité entre les deux critères peut également être inférée
du texte du paragraphe 1 de l’article 76 de la convention, dont la Cour considère
qu’il reflète le droit international coutumier (Différend territorial et
maritime (Nicaragua c. Colombie), arrêt, C.I.J. Recueil 2012 (II), p. 666,
par. 118).
Le paragraphe 1 de l’article 76 se lit comme suit :
« Le plateau continental d’un État côtier comprend les fonds marins et
leur sous-sol au-delà de sa mer territoriale, sur toute l’étendue du prolongement
naturel du territoire terrestre de cet État jusqu’au rebord externe
de la marge continentale, ou jusqu’à 200 milles marins des lignes de
base à partir desquelles est mesurée la largeur de la mer territoriale,
lorsque le rebord externe de la marge continentale se trouve à une distance
inférieure. »
Par cette disposition, un critère de distance vient s’ajouter au critère du prolongement
naturel dans la définition du plateau continental. Un État côtier
dont la marge continentale n’atteint pas 200 milles marins peut revendiquer
un plateau continental jusqu’à 200 milles marins, indépendamment des
conditions géologiques ou géophysiques. La disposition qui établit ce droit,
lue dans son sens ordinaire, ne dit aucunement que les deux critères s’ap489
delimitation of the continental shelf (sep. op. xue)
distinct parts of the continental shelf, that is to say, that the distance criterion
applies to the continental shelf within 200 nautical miles while natural
prolongation criterion is only applicable to the extended continental shelf,
as suggested in the Judgment (para. 75). For any single continental shelf, it
may be defined by either one of the criteria, depending on the physical
circumstances of the continental margin concerned. Between the two criteria,
there is neither priority nor precedence (Delimitation of the Maritime
Boundary between Guinea and Guinea-Bissau (Guinea/Guinea-Bissau),
Award of 14 February 1985, RIAA, Vol. XIX, p. 191, para. 116). If the
distance criterion were indeed given precedence over natural prolongation
within 200 nautical miles, the text of Article 76, paragraph 1, must have been
written differently to indicate such a hierarchy, because it would otherwise
annul the entitlement to certain extended continental shelves that coastal
States enjoy ipso facto and ab initio and would fundamentally change the
basis of continental shelf entitlements under customary international law.
Apparently, no such understanding can be found in the text of Article 76.
16. In analysing the terms of the continental shelf under Article 76, the
Court infers an assumption of negotiating States from the mechanism established
under Article 76, paragraph 8, of UNCLOS that an extended
continental shelf would only extend into maritime areas that would otherwise
be located in the “Area”, hence denying the possibility that an extended
continental shelf of one State may extend within 200 nautical miles from the
baselines of another State (Judgment, para. 76). In this regard, it refers to
Article 82 on payments and contributions to the International Seabed
Authority in respect of exploitation of the non-living resources of the
extended continental shelf and states that
“[s]uch a payment would not serve the purpose of this provision in a situation
where the extended continental shelf of one State extended within
200 nautical miles from the baselines of another State”.
Furthermore, it observes that the issue before the Court with regard to the
extended continental shelf of one State extending within 200 nautical miles
of another State “was not debated” during the Law of the Sea Conference
(ibid.).
17. In the present case, Nicaragua’s claim obviously does not concern the
Area, nor did the Parties refer to it during the proceedings. It is true that the
limitation on the continental shelf beyond 200 nautical miles and the Article
82 mechanism are designed to protect the Area and its resources as the
common heritage of mankind, but they are irrelevant to the present situation.
It is questionable whether an inference could be drawn from this treaty
mechanism that the distance criterion was provided as the primary entitlement
to a continental shelf within 200 nautical miles to trump an overlapping
entitlement based on natural prolongation. The assumption inferred from
délimitation du plateau continental (op. ind. xue) 489
pliquent chacun à deux parties distinctes du plateau continental, autrement
dit, que le critère de la distance s’appliquerait au plateau continental dans la
limite de 200 milles marins, tandis que le critère du prolongement naturel ne
s’appliquerait qu’au plateau continental étendu, comme il est laissé entendre
dans l’arrêt (par. 75). Tout plateau continental peut être défini par l’un ou
l’autre des critères, en fonction des caractéristiques physiques de la marge
continentale concernée. Entre les deux critères, il n’y a ni priorité ni hiérarchie
(Délimitation de la frontière maritime entre la Guinée et la
Guinée-Bissau (Guinée/Guinée-Bissau), sentence du 14 février 1985, RSA,
vol. XIX, p. 191, par. 116). Si le critère de la distance primait effectivement
celui du prolongement naturel en deçà de 200 milles marins, le paragraphe 1
de l’article 76 aurait dû être rédigé différemment, de manière à préciser cette
hiérarchie, car cela reviendrait autrement à annuler, s’agissant de certains
plateaux continentaux étendus, le droit dont les États côtiers jouissent ipso
facto et ab initio à leur égard, et cela modifierait fondamentalement la base
des droits à un plateau continental reconnus en droit international coutumier.
À l’évidence, rien de tel ne peut être lu dans le texte de l’article 76.
16. En analysant les conditions applicables au plateau continental telles
qu’elles sont définies à l’article 76 de la CNUDM, la Cour infère, de la mise
en place du mécanisme prévu au paragraphe 8 de cet article, que les États
participant aux négociations considéraient que le plateau continental étendu
ne pouvait se prolonger que dans des espaces maritimes qui, autrement,
feraient partie de la « Zone », excluant ainsi la possibilité que le plateau continental
étendu d’un État se prolonge en deçà de 200 milles marins des lignes
de base d’un autre État (arrêt, par. 76). À ce propos, la Cour renvoie à l’article
82 relatif aux contributions en espèces ou en nature qui doivent être
versées à l’Autorité internationale des fonds marins au titre de l’exploitation
des ressources non biologiques du plateau continental étendu, et affirme que
« [u]ne telle contribution ne servirait pas l’objectif de cette disposition
dans le cas où le plateau continental d’un État au-delà de 200 milles
marins s’étendrait à des espaces maritimes en deçà de 200 milles marins
des lignes de base d’un autre État ».
La Cour relève en outre que la question qui lui a été soumise concernant la
possibilité que le plateau continental étendu d’un État se prolonge en deçà de
200 milles marins des côtes d’un autre État « n’a pas été débattue » pendant
la conférence sur le droit de la mer (ibid.).
17. En l’espèce, la demande du Nicaragua ne concernait manifestement pas
la Zone, à laquelle les Parties n’ont d’ailleurs pas fait référence au cours de la
procédure. Il est vrai que les limites fixées au plateau continental au-delà de
200 milles marins et le mécanisme prévu à l’article 82 de la CNUDM ont
vocation à protéger la Zone et ses ressources en tant que patrimoine commun
de l’humanité, mais n’ont aucune pertinence pour la situation en l’espèce. Il
est douteux que l’on puisse inférer de ce mécanisme conventionnel l’hypothèse
que la distance ait été retenue comme critère pour la détermination du
droit premier à un plateau continental dans la limite de 200 milles marins,
490 delimitation of the continental shelf (sep. op. xue)
Articles 76 and 82 of UNCLOS, even if established, does not necessarily
lead to the conclusion that the mechanism under Article 82 has the consequential
effect of restricting a State’s entitlement to an extended continental
shelf from extending within 200 nautical miles of another State. What has
been agreed by the States in the “package deal” remains in the text of the
treaty. What is not included should continue to be governed by customary
international law. The absence of discussions of the issue during the negotiations
at the Law of the Sea Conference does not reinforce the Court’s
reasoning. On the contrary, that fact weakens it. The negotiating parties did
not debate the issue simply because they saw no need to do so. As is observed,
“[t]he establishment of a maritime area in which the States concerned
have shared rights is not unknown under the Convention. The Convention
is replete with provisions that recognize to a greater or lesser degree
the rights of one State within the maritime zones of another.” (Bay of
Bengal Maritime Boundary Arbitration (Bangladesh v. India), Award of
7 July 2014, RIAA, Vol. XXXII, pp. 148-149, para. 507.)
Overlapping continental shelf entitlements based on different criteria could
well have been envisaged when the distance criterion was introduced into
Article 76, paragraph 1. Unless otherwise provided, a hierarchical relationship
between the two criteria cannot be construed from the simple fact that
there are a very large number of States parties to UNCLOS. Moreover, to
what extent the relevant treaty rules have passed into the corpus of customary
international law is still a question to be determined under customary
international law. In other words, the Court has to ascertain whether there is
a general State practice and acceptance of such practice as law (opinio juris)
that support a customary rule as identified by the Court. In this regard,
“two conditions must be fulfilled. Not only must the acts concerned
amount to a settled practice, but they must also be such, or be carried out
in such a way, as to be evidence of a belief that this practice is rendered
obligatory by the existence of a rule of law requiring it” (North Sea
Continental Shelf (Federal Republic of Germany/Denmark; Federal
Republic of Germany/Netherlands), Judgment, I.C.J. Reports 1969,
p. 44, para. 77; see also Conclusions 2 and 9 of the Draft conclusions on
identification of customary international law, with commentaries,
adopted by the International Law Commission in 2018 (hereinafter
“ILC Conclusions”, UN doc. A/73/10, pp. 122-156).
18. In determining the existence and content of a customary rule that may
have evolved from a treaty rule, the Court in the North Sea Continental Shelf
délimitation du plateau continental (op. ind. xue) 490
afin de primer tout droit concurrent à un plateau continental fondé sur le prolongement
naturel. L’hypothèse inférée des articles 76 et 82 de la convention,
même si elle se vérifiait, ne conduirait pas nécessairement à la conclusion que
le mécanisme prévu à l’article 82 a pour effet de restreindre le droit d’un
État à un plateau continental étendu se prolongeant en deçà de 200 milles
marins des côtes d’un autre État. Ce qui a été convenu par les États dans le
compromis global (package deal) est dans le texte de la convention. Ce qui
n’y figure pas reste régi par le droit international coutumier. Le fait que cette
question n’ait pas été débattue à la conférence sur le droit de la mer ne vient
pas renforcer le raisonnement de la Cour. Au contraire, il l’affaiblit. Les États
participants aux négociations n’ont pas abordé la question pour la simple raison
qu’ils n’en voyaient pas la nécessité. Ainsi qu’il a été relevé,
« [l]a création d’un espace maritime dans lequel les États concernés ont
des droits partagés n’est pas une anomalie au regard de la convention.
Celle-ci regorge de dispositions qui reconnaissent à des degrés divers les
droits d’un État dans les espaces maritimes d’un autre. » (Arbitrage
concernant la frontière maritime dans le golfe du Bengale (Bangladesh
c. Inde), sentence du 7 juillet 2014, RSA, vol. XXXII, p. 148-149,
par. 507.)
Il est fort possible que le chevauchement de plateaux continentaux déterminés
selon des critères différents ait été envisagé lorsque le critère de la
distance a été introduit au paragraphe 1 de l’article 76 de la CNUDM. En l’absence
de disposition contraire, l’existence d’une relation hiérarchique entre
les deux critères ne peut être inférée du simple fait que les États parties à la
convention soient très nombreux. En outre, la question de savoir dans quelle
mesure les règles conventionnelles pertinentes sont passées dans le corpus du
droit international coutumier doit encore être tranchée au regard de ce droit.
En d’autres termes, la Cour doit s’assurer qu’une règle qu’elle identifie comme
coutumière est bien confirmée par une pratique générale des États et par l’acceptation
de cette pratique comme étant le droit (opinio juris). À cet égard,
« deux conditions doivent être remplies. Non seulement les actes considérés
doivent représenter une pratique constante, mais en outre ils doivent
témoigner, par leur nature ou la manière dont ils sont accomplis, de la
conviction que cette pratique est rendue obligatoire par l’existence
d’une règle de droit » (Plateau continental de la mer du Nord (République
fédérale d’Allemagne/Danemark ; République fédérale d’Allemagne/
Pays-Bas), arrêt, C.I.J. Recueil 1969, p. 44, par. 77 ; voir également les
conclusions 2 et 9 des projets de conclusion sur la détermination du droit
international coutumier adoptés en 2018 par la Commission du droit
international (ci-après les « conclusions de la CDI », Nations Unies,
doc. A/73/10, p. 122-156).
18. S’agissant de déterminer l’existence et le contenu d’une règle coutumière
susceptible d’avoir évolué à partir d’une règle conventionnelle, la
491 delimitation of the continental shelf (sep. op. xue)
cases highlighted an indispensable requirement for the consideration of the
State practice under the treaty rule concerned, according to which,
“State practice, including that of States whose interests are specially
affected, should have been both extensive and virtually uniform in the
sense of the provision invoked; — and should moreover have occurred
in such a way as to show a general recognition that a rule of law or legal
obligation is involved” (North Sea Continental Shelf (Federal Republic
of Germany/Denmark; Federal Republic of Germany/Netherlands),
Judgment, I.C.J. Reports 1969, p. 43, para. 74).
In assessing the evidence, regard must be had to the overall context, the
nature of the rule and the particular circumstances in which the evidence in
question is to be found (Conclusion 3 of the ILC Conclusions).
19. In assessing these two constitutive elements for the identification of a
customary rule, the Court relies heavily on the relationship of the régimes of
the exclusive economic zone and of the continental shelf as provided for in
Article 56, paragraph 3, of UNCLOS and on States parties’ submissions to
the Commission on the Limits of the Continental Shelf (hereinafter the
“CLCS” or “Commission”). It is this part of the reasoning that I find most
unpersuasive and problematic. It flies in the face of State practice and
well-settled jurisprudence of the Court.
B. Relationship between the Régimes of the Continental Shelf
and of the Exclusive Economic Zone
20. In recalling the negotiating history of UNCLOS, the Court refers to the
relationship between the régimes of the exclusive economic zone and of the
continental shelf. In the Court’s view, since a coastal State enjoys in the
exclusive economic zone, inter alia, sovereign rights over the non-living
resources in the seabed and subsoil within 200 nautical miles and since such
rights shall be exercised in accordance with the rules applicable to the continental
shelf, the two régimes are interrelated. Based on that link, the Court
assumed that the entitlement to an extended continental shelf may not extend
within 200 nautical miles because such an extension would encroach on the
attendant exclusive economic zone of the coastal State. This inference, in my
view, overstates the import of Article 56, paragraph 3.
21. First of all, the interrelationship between the régimes of the exclusive
economic zone and of the continental shelf as provided for in Article 56 does
not give a prevailing effect to the exclusive economic zone over the continental
shelf. While Article 56, paragraph 3, links the two zones, it does not go
so far as to say that the two zones are inseparable in maritime delimitation
délimitation du plateau continental (op. ind. xue) 491
Cour, dans les affaires du Plateau continental de la mer du Nord, a insisté
sur une condition indispensable pour apprécier la pratique des États au
regard de la règle conventionnelle en question, à savoir que
« la pratique des États, y compris ceux qui sont particulièrement intéressés,
[doit avoir] été fréquente et pratiquement uniforme dans le sens de la
disposition invoquée et [s’être] manifestée de manière à établir une
reconnaissance générale du fait qu’une règle de droit ou une obligation
juridique est en jeu » (Plateau continental de la mer du Nord (République
fédérale d’Allemagne/Danemark ; République fédérale d’Allemagne/
Pays-Bas), arrêt, C.I.J. Recueil 1969, p. 43, par. 74).
Dans l’appréciation des moyens de preuve, il faut tenir compte du contexte
général, de la nature de la règle et des circonstances propres à chacun de ces
moyens (conclusion 3 des conclusions de la CDI).
19. Dans son évaluation de ces deux éléments constitutifs de la détermination
d’une règle coutumière, la Cour accorde un poids considérable à la
relation, mentionnée au paragraphe 3 de l’article 56 de la CNUDM, qui
existe entre les régimes respectifs de la zone économique exclusive et du plateau
continental, ainsi qu’aux demandes présentées par les États parties à la
Commission des limites du plateau continental (ci-après la « Commission
des limites »). C’est cette partie du raisonnement que je trouve la moins
convaincante et la plus problématique. Elle va à l’encontre de la pratique des
États et de la jurisprudence bien établie de la Cour.
B. La relation entre le régime du plateau continental
et celui de la zone économique exclusive
20. Lorsqu’elle rappelle l’historique des négociations de la CNUDM, la
Cour évoque la relation entre les régimes respectifs de la zone économique
exclusive et du plateau continental. Selon elle, puisqu’un État côtier jouit
dans la zone économique exclusive, entre autres, de droits souverains sur les
ressources non biologiques des fonds marins et de leur sous-sol dans la
limite de 200 milles marins, et que ces droits s’exercent conformément aux
règles applicables au plateau continental, les deux régimes sont interreliés.
Au vu de ce lien, la Cour présume que le plateau continental étendu auquel
un État peut prétendre ne peut pas se prolonger en deçà de 200 milles marins
des côtes d’un autre État, parce qu’une telle extension empiéterait sur la zone
économique exclusive correspondante de l’État côtier. Par cette déduction, la
Cour surestime, à mon sens, l’importance du paragraphe 3 de l’article 56 de
la convention.
21. Tout d’abord, l’interrelation du régime de la zone économique exclusive
avec celui du plateau continental, telle qu’énoncée à l’article 56, n’a pas
pour effet de donner priorité à la première sur le second. Si le paragraphe 3
de l’article 56 relie bien les deux zones, il ne va toutefois pas jusqu’à dire
qu’elles sont indissociables dans une délimitation maritime et que les espaces
492 delimitation of the continental shelf (sep. op. xue)
and that maritime entitlements within 200 nautical miles by their very nature
shall take precedence over an extended continental shelf entitlement. States’
positions as well as their practice are divided on the question whether the
two criteria under Article 76, paragraph 1, are of equal applicability or hierarchical
in effect. They differ as to whether the water column and the seabed
within 200 nautical miles may be delimited separately. Among scholars,
views on the subject-matter also vary greatly1. This is indeed an area that the
“package deal” was ambiguous about. On the relationship between the two
régimes, one analysis of Article 56, paragraph 3, is pertinent in the present
context:
“The text of Article 56 (3) is a clear indication of the applicable law,
which might result from the idea that the continental shelf and the EEZ
are essentially dealing with different natural resources. Whereas the
continental shelf confers on coastal States exclusive rights over the
exploration and exploitation of the non-living resources and sedentary
resources in the seabed and subsoil, the EEZ is more concerned with living
resources in the water column, in particular fisheries. It is therefore
in line with the functional purposes of the two regimes if the continental
shelf regime applies to the seabed and subsoil, even if the area is within
the reach of the EEZ.”2
This understanding is consistent with the concept of a single continental
shelf. The continental shelf régime applies to the seabed and subsoil irrespective
of the basis of the entitlement, natural prolongation or distance.
While the inclusion of the sovereign rights over the seabed and subsoil in the
régime of the exclusive economic zone may reinforce the continental shelf
entitlement within 200 nautical miles, Article 56, by its own terms, only
concerns the content and exercise of substantive rights.
22. Judicial and arbitral decisions generally recognize the autonomy and
distinction of the two régimes. In the present case, however, the Court draws
a different reading from its 1985 Judgment in the Continental Shelf (Libyan
Arab Jamahiriya/Malta) case, where the Court observed that, “[a]lthough
there can be a continental shelf where there is no exclusive economic zone,
there cannot be an exclusive economic zone without a corresponding continental
shelf” (Judgment, I.C.J. Reports 1985, p. 33, para. 34). Based on this
1 Malcolm D. Evans, “Delimitation and the Common Maritime Boundary”, British Yearbook
of International Law, 1994, Vol. 64 (1), p. 283; Xuexia Liao, “Is There a Hierarchical
Relationship between Natural Prolongation and Distance in the Continental Shelf Delimitation?”,
The International Journal of Marine and Coastal Law, 2018, Vol. 33, pp. 105-110.
2 Xuexia Liao, “Is There a Hierarchical Relationship between Natural Prolongation and
Distance in the Continental Shelf Delimitation?”, The International Journal of Marine and
Coastal Law, 2018, Vol. 33, pp. 106-107.
délimitation du plateau continental (op. ind. xue) 492
maritimes qui peuvent être revendiqués dans la limite de 200 milles marins
ont priorité, par leur nature même, sur le plateau continental étendu. Les
États ont des vues et des pratiques différentes s’agissant de considérer les
deux critères du paragraphe 1 de l’article 76 comme étant d’application égale
ou hiérarchisés. Ils ne s’accordent pas sur le point de savoir si la colonne
d’eau et les fonds marins dans la limite de 200 milles marins peuvent être
délimités séparément. La doctrine est également très partagée sur ce sujet1.
Le compromis global (package deal) est assurément ambigu à cet égard.
L’analyse suivante du paragraphe 3 de l’article 56 est pertinente, dans le
contexte de l’espèce, pour apprécier la relation entre les deux régimes :
« Le texte du paragraphe 3 de l’article 56 donne une claire indication
du droit applicable, qui peut découler de l’idée que le plateau continental
et la zone économique exclusive concernent essentiellement des
ressources naturelles différentes. Alors que, s’agissant du plateau continental,
les États côtiers ont des droits souverains et exclusifs d’exploration
et d’exploitation des ressources non biologiques et sédentaires des fonds
marins et de leur sous-sol, dans le cas de la zone économique exclusive
ce sont plutôt les ressources biologiques de la colonne d’eau, en particulier
les pêcheries. Il est donc cohérent avec les objectifs fonctionnels
des deux régimes que celui du plateau continental s’applique aux fonds
marins et à leur sous-sol même si la zone concernée atteint la zone
économique exclusive. »2
Cette interprétation est compatible avec la notion de plateau continental
unique. Le régime du plateau continental s’applique aux fonds marins et à
leur sous-sol, indépendamment du fondement — prolongement naturel ou
distance — sur lequel est revendiqué le plateau continental. Si l’inclusion de
droits souverains sur les fonds marins et leur sous-sol dans le régime de la
zone économique exclusive peut renforcer le droit à un plateau continental
dans la limite de 200 milles marins, l’article 56, par son libellé, ne concerne
que le contenu et l’exercice de droits substantiels.
22. Les décisions judiciaires et arbitrales confirment généralement que les
deux régimes sont autonomes et distincts. Dans le présent arrêt, cependant,
la Cour donne une lecture différente de celui qu’elle a rendu en 1985 en l’affaire
du Plateau continental (Jamahiriya arabe libyenne/Malte), où elle
faisait observer que, « [s]’il peut y avoir un plateau continental sans zone économique
exclusive, il ne saurait exister de zone économique exclusive sans
plateau continental correspondant » (arrêt, C.I.J. Recueil 1985, p. 33, par. 34).
1 Malcolm D. Evans, « Delimitation and the Common Maritime Boundary », British Yearbook
of International Law, 1994, vol. 64 (1), p. 283 ; Xuexia Liao, « Is There a Hierarchical
Relationship between Natural Prolongation and Distance in the Continental Shelf Delimitation?
», The International Journal of Marine and Coastal Law, 2018, vol. 33, p. 105-110.
2 Xuexia Liao, « Is There a Hierarchical Relationship between Natural Prolongation and
Distance in the Continental Shelf Delimitation? », The International Journal of Marine and
Coastal Law, 2018, vol. 33, p. 106-107.
493 delimitation of the continental shelf (sep. op. xue)
statement, the Court now considers that, with the distance criterion as the
sole basis of entitlement of the coastal State to both the exclusive economic
zone and the continental shelf within 200 nautical miles, an extended continental
shelf of one State may not extend within 200 nautical miles of another
State.
23. This finding, first of all, implies that, with the distance criterion applicable
to both régimes, the concept of the continental shelf within 200 nautical
miles has been absorbed by that of the exclusive economic zone under the
contemporary law of the sea, an implication that the Court categorically
rejected in the same Judgment (see Continental Shelf (Libyan Arab Jamahiriya/
Malta), Judgment, I.C.J. Reports 1985, p. 33, para. 33). Following the
above statement cited by the Court, the Court in that case went on stating
that,
“for juridical and practical reasons, the distance criterion must now
apply to the continental shelf as well as to the exclusive economic zone;
and this quite apart from the provision as to distance in paragraph 1 of
Article 76. This is not to suggest that the idea of natural prolongation is
now superseded by that of distance. What it does mean is that where the
continental margin does not extend as far as 200 miles from the shore,
natural prolongation . . . is in part defined by distance from the shore,
irrespective of the physical nature of the intervening sea-bed and subsoil.
The concepts of natural prolongation and distance are therefore not
opposed but complementary; and both remain essential elements in the
juridical concept of the continental shelf.” (Ibid., para. 34; emphasis
added.)
This statement shows that the interrelationship between the two régimes as
defined in Article 56, paragraph 3, is not conclusive on the question that the
Court is dealing with in the present case, namely, whether there is priority
accorded to the entitlement within 200 nautical miles over an extended continental
shelf. Moreover, the factual situation of that case is entirely different
from the present one. In the former, the distance between the parties is less
than 400 nautical miles, where geographical or geophysical factors could be
disregarded, while in the latter, the Applicant’s claim to an extended continental
shelf depends on the technical and scientific evidence that may
establish the existence of the natural prolongation of its land territory. Once
the natural prolongation is established, the Applicant is entitled to the
extended continental shelf. What the Court stated in the context of the Libyan
Arab Jamahiriya/Malta case did not address the question of entitlement
but of delimitation. At the time of that case, with UNCLOS not yet in force
and the customary status of Article 76, paragraph 1, with regard to the distance
criterion still in doubt, the Court took the legally permissible extent of
the exclusive economic zone appertaining to a given State as “one of the
relevant circumstances to be taken into account for the delimitation of
délimitation du plateau continental (op. ind. xue) 493
Sur la base de ce constat, la Cour considère à présent que, le critère de la
distance étant le seul fondement du droit de l’État côtier à la fois à une zone
économique exclusive et à un plateau continental dans la limite de 200 milles
marins, le plateau continental étendu d’un État ne peut pas empiéter sur l’espace
de 200 milles marins d’un autre État.
23. Cette conclusion, tout d’abord, signifie que, si le critère de la distance
est applicable aux deux régimes, la notion du plateau continental de
200 milles marins est recouverte par celle de la zone économique exclusive
en droit de la mer contemporain, une hypothèse que la Cour avait catégoriquement
rejetée dans ce même arrêt (voir Plateau continental (Jamahiriya
arabe libyenne/Malte, arrêt, C.I.J. Recueil 1985, p. 33, par. 33). À la suite du
constat suscité, elle avait déclaré que,
« pour des raisons tant juridiques que pratiques, le critère de distance
doit dorénavant s’appliquer au plateau continental comme à la zone économique
exclusive — et cela indépendamment de la disposition relative
à la distance que l’on trouve au paragraphe 1 de l’article 76. Ce n’est pas
à dire que l’idée de prolongement naturel soit maintenant remplacée
par celle de distance. Ce que cela signifie c’est que, lorsque la marge
continentale elle-même n’atteint pas les 200 milles, le prolongement
naturel … se définit en partie par la distance du rivage, quelle que soit la
nature physique du fond et du sous-sol de la mer en deçà de cette distance.
Par conséquent les notions de prolongement naturel et de distance
ne sont pas des notions opposées mais complémentaires, qui demeurent
l’une et l’autre des éléments essentiels de la conception juridique du
plateau continental. » (Ibid., p. 33-34, par. 34 ; les italiques sont de moi.)
Il ressort de cette déclaration que l’interrelation entre les deux régimes, telle
que définie au paragraphe 3 de l’article 56 de la convention, n’est pas probante
pour répondre à la question qui se pose à la Cour en l’espèce, celle de
savoir si le plateau continental auquel un État a droit dans la limite de
200 milles marins a priorité sur le plateau continental étendu auquel un autre
État peut prétendre. De plus, la situation factuelle dans l’affaire ci-dessus
diffère complètement de celle de la présente instance. Dans la première, les
territoires des parties sont séparés par un espace de moins de 400 milles
marins, dans lequel les facteurs géographiques ou géophysiques pouvaient
être négligés, tandis que, dans la seconde, la prétention du demandeur à un
plateau continental étendu est subordonnée à l’établissement par des preuves
techniques et scientifiques de l’existence d’un prolongement naturel de son
territoire terrestre. Une fois ce prolongement naturel attesté, le demandeur a
droit au plateau continental étendu. Ce que la Cour a dit dans le contexte de
l’affaire Jamahiriya arabe libyenne/Malte concernait non pas le titre à un
plateau continental mais la délimitation. À l’époque, la CNUDM n’était pas
encore en vigueur, le statut coutumier du paragraphe 1 de l’article 76 relatif
au critère de la distance était encore incertain, et la Cour a donc considéré
494 delimitation of the continental shelf (sep. op. xue)
the continental shelf ” of that State (ibid., para. 33; emphasis added). By
granting greater importance to the element of distance, which is common to
both régimes, in the delimitation of continental shelf within 200 nautical
miles, the Court only tried to reach an equitable solution but not to pronounce
a general rule restricting natural prolongation.
24. Even supposing that the Court’s statement in the Continental Shelf
(Libyan Arab Jamahiriya/Malta) case did constitute a general legal pronouncement,
one may still wonder when the putative rule as identified by
the Court in this case formed part of customary international law, because
the judicial and arbitral decisions and State practice on the delimitation of
continental shelf subsequent to the 1985 Judgment do not support such a
proposition.
25. In the Bay of Bengal cases, the International Tribunal for the Law of
the Sea (ITLOS) and the arbitral tribunal established under Annex VII of
UNCLOS respectively delimited the maritime boundary including the
extended continental shelf between the parties to each case. The adjustment
of the provisional equidistance line resulted in a “grey area” of limited size
in both cases, which is located within the 200-nautical-mile limit of the coast
of one party but on the other party’s side of the line that delimits the parties’
continental shelves (Delimitation of the Maritime Boundary in the Bay of
Bengal (Bangladesh/Myanmar), Judgment, ITLOS Reports 2012, p. 119,
para. 463; Bay of Bengal Maritime Boundary Arbitration between Bangladesh
and India, Award of 7 July 2014, RIAA, Vol. XXXII, p. 147, para. 498).
The Court dismisses the Applicant’s argument based on these cases, which
it considers irrelevant for the consideration of the present case, because, in
its view, the grey area is “an incidental result” of the adjustment of the provisional
equidistance line and the circumstances in those cases are distinct
from the situation in the present case (Judgment, para. 72).
26. In Somalia v. Kenya  a case it has recently adjudicated  the Court
observed that if the delimitation line, as determined, continues on the course
beyond 200 nautical miles, it might give rise to an area of limited size lying
within 200 nautical miles of the coast of Somalia but on the Kenyan side of
the boundary, thus resulting in a similar “grey area” as in the Bay of Bengal
cases (Maritime Delimitation in the Indian Ocean (Somalia v. Kenya), Judgment,
I.C.J. Reports 2021, p. 277, para. 197). The Court again dismisses the
relevance of the case, stating that the grey area is merely a possibility and
that, therefore, there is no need to take it into account (Judgment, para. 73).
27. This approach taken by the Court appears hasty and evasive. In these
three cases, the “grey area”, albeit incidental in nature and small in size, is in
itself a piece of hard evidence that disproves at least the inseparability of the
two zones in the maritime delimitation. Convenient or not, it evinces that the
délimitation du plateau continental (op. ind. xue) 494
que l’étendue autorisée en droit de la zone économique exclusive revenant à
un État donné était « l’une des circonstances pertinentes à prendre en
compte pour la délimitation du plateau continental » de cet État (ibid., p. 33,
par. 33 ; les italiques sont de moi). En accordant une plus grande importance
à l’élément de la distance, qui est commun aux deux régimes, dans la délimitation
du plateau continental jusqu’à 200 milles marins, la Cour cherchait
seulement à trouver une solution équitable, et non à établir une règle générale
restreignant le critère du prolongement naturel.
24. Même à supposer que ce qu’a dit la Cour dans l’affaire du Plateau
continental (Jamahiriya arabe libyenne/Malte) constitue bien une interprétation
juridique générale, on peut néanmoins se demander à quel moment la
règle putative qu’elle a identifiée dans cette affaire est devenue coutumière,
car les décisions judiciaires et arbitrales et la pratique des États en matière de
délimitation du plateau continental postérieures à l’arrêt de 1985 ne viennent
pas le confirmer.
25. Dans les affaires relatives au Golfe du Bengale, le Tribunal international
du droit de la mer (TIDM) et le tribunal arbitral constitué en application
de l’annexe VII de la CNUDM ont chacun délimité la frontière maritime, y
compris le plateau continental étendu, entre les parties concernées. L’ajustement
de la ligne d’équidistance provisoire a donné lieu dans les deux cas à
une « zone grise » de taille réduite, située en deçà de 200 milles marins des
côtes d’une partie mais au-delà de la ligne séparant son plateau continental
de celui de l’autre partie (Délimitation de la frontière maritime dans le golfe
du Bengale (Bangladesh/Myanmar), arrêt, TIDM Recueil 2012, p. 119,
par. 463 ; Arbitrage concernant la frontière maritime dans le golfe du Bengale
(Bangladesh c. Inde), sentence du 7 juillet 2014, RSA, vol. XXXII,
p. 147, par. 498). La Cour a rejeté l’argument que le Nicaragua tirait de ces
précédents, jugeant ceux-ci non pertinents pour la présente affaire parce que,
selon elle, la zone grise était une « conséquence fortuite » de l’ajustement de
la ligne d’équidistance provisoire et les circonstances dans ces affaires-là
étaient distinctes de la situation en l’espèce (arrêt, par. 72).
26. Dans l’affaire Somalie c. Kenya, sur laquelle elle a statué récemment,
la Cour a fait observer que, si la ligne de délimitation, telle qu’établie, se prolongeait
au-delà de 200 milles marins, cela pouvait créer une zone de taille
limitée située à moins de 200 milles marins des côtes somaliennes mais du
côté kényan de la frontière, créant ainsi une « zone grise » similaire à celle
des affaires relatives au Golfe du Bengale (Délimitation maritime dans
l’océan Indien (Somalie c. Kenya), arrêt, C.I.J. Recueil 2021, p. 277, par. 197).
Là encore, la Cour a considéré que ce précédent n’était pas pertinent en l’espèce,
la zone grise n’étant qu’une éventualité dont il n’est donc pas nécessaire,
selon elle, de tenir compte (arrêt, par. 73).
27. Cette approche de la Cour semble hâtive et évasive. Dans les trois
affaires, la « zone grise », même si elle est fortuite et de taille réduite, est en
soi un élément de preuve solide qui dément au moins l’inséparabilité des
deux espaces en question dans la délimitation maritime. Opportune ou non,
495 delimitation of the continental shelf (sep. op. xue)
exclusive economic zone does not dictate the delimitation of the continental
shelf. As ITLOS observed in the Bangladesh/Myanmar case,
“the legal regime of the continental shelf has always coexisted with
another legal regime in the same area. Initially that other regime was
that of the high seas and the other States concerned were those exercising
high seas freedoms. Under the Convention, as a result of maritime
delimitation, there may also be concurrent exclusive economic zone
rights of another coastal State.” (Delimitation of the Maritime Boundary
in the Bay of Bengal (Bangladesh/Myanmar), Judgment, ITLOS Reports
2012, p. 121, para. 475.)
Evidently, these judicial and arbitral organs do not consider that there existed
a customary rule by which an extended continental shelf of one State may
not extend within the exclusive economic zone of another State, as a matter
of entitlement. When an overlap of entitlements occurs, the matter is one of
delimitation. Article 83 of UNCLOS, on purpose, leaves sufficient room for
the relevant circumstances of each case to be considered in the delimitation
process.
28. In practice, States not only claim an entitlement to an extended continental
shelf that may extend within 200 nautical miles of another State, but
also draw maritime boundaries by agreement that delimit the exclusive economic
zone and the continental shelf separately. They do it either by separate
agreements dealing with different zones, or simply by drawing different
boundary lines within the same agreement.
29. Australia and Indonesia, for example, concluded an agreement on the
continental shelf boundary in the Timor and Arafura Seas in 1972 (Agreement
between the Government of the Commonwealth of Australia and the
Government of the Republic of Indonesia establishing certain seabed boundaries
in the area of the Timor and Arafura Seas, supplementary to the
Agreement of 18 May 1971, concluded 9 October 1972, entered into force
8 November 1973, United Nations, Treaty Series (UNTS), Vol. 974, p. 319).
In 1997, the two States concluded another agreement on the exclusive economic
zone boundary and the western extension of the seabed boundary
(Agreement between the Government of Australia and the Government of
the Republic of Indonesia establishing an exclusive economic zone boundary
and certain seabed boundaries, concluded 14 March 1997, not yet in
force, International Legal Materials, 1997, Vol. 36, p. 1053). The latter
agreement drew the continental shelf boundary on the basis of the geological
and geophysical factors of the Timor Trough, while the boundary of the
exclusive economic zone was drawn on the basis of distance; the former line
is closer to the Indonesian side. As a result of these two agreements, there are
several overlapping areas where Australia’s extended continental shelf is
délimitation du plateau continental (op. ind. xue) 495
elle montre que la zone économique exclusive ne dicte pas la délimitation du
plateau continental. Comme l’a relevé le TIDM dans l’affaire Bangladesh/
Myanmar,
« le régime juridique du plateau continental coexiste depuis toujours
avec un autre régime juridique dans la même zone. À l’origine, cet autre
régime était celui de la haute mer et les autres États concernés étaient
ceux qui exerçaient la liberté de la haute mer. En vertu de la Convention,
par suite de la délimitation maritime, il peut également exister des droits
concurrents d’un autre État côtier sur la zone économique exclusive. »
(Délimitation de la frontière maritime dans le golfe du Bengale (Bangladesh/
Myanmar), arrêt, TIDM Recueil 2012, p. 121, par. 475.)
À l’évidence, ces instances judiciaires et arbitrales ne considèrent pas qu’il
existerait une règle coutumière excluant que le plateau continental étendu
d’un État puisse se prolonger dans la zone économique exclusive d’un autre
État, s’agissant des droits respectifs des États à ces espaces. Lorsqu’il y a
chevauchement de ces droits, cela devient une question de délimitation. L’article
83 de la CNUDM laisse délibérément une marge de manoeuvre suffisante
pour qu’il puisse être tenu compte des circonstances pertinentes dans chaque
processus de délimitation.
28. Dans la pratique, des États non seulement revendiquent un plateau
continental étendu susceptible de se prolonger en deçà de 200 milles marins
des côtes d’un autre État, mais s’entendent également pour tracer des frontières
maritimes qui délimitent séparément la zone économique exclusive et
le plateau continental. Ils le font soit par des accords distincts portant sur des
zones distinctes, soit, simplement, en délimitant des frontières distinctes
dans un même accord.
29. L’Australie et l’Indonésie, par exemple, ont conclu en 1972 un accord
sur la délimitation du plateau continental dans les mers de Timor et d’Arafura
(accord entre le Gouvernement du Commonwealth d’Australie et le
Gouvernement de la République d’Indonésie instituant certaines lignes délimitant
les fonds marins dans la zone des mers de Timor et d’Arafura,
complétant l’accord du 18 mai 1971, conclu le 9 octobre 1972, entré en
vigueur le 8 novembre 1973, Recueil des traités des Nations Unies (RTNU),
vol. 974, p. 319). En 1997, ces deux États ont conclu un autre accord sur la
délimitation de la zone économique exclusive et l’extension vers l’ouest de la
délimitation des fonds marins (accord entre le Gouvernement d’Australie et
le Gouvernement de la République d’Indonésie instituant une ligne délimitant
une zone économique exclusive et certaines lignes délimitant les fonds
marins, conclu le 14 mars 1997, non entré en vigueur, International Legal
Materials, 1997, vol. 36, p. 1053). Par ce dernier accord, la limite du plateau
continental a été définie sur la base des facteurs géologiques et géophysiques
de la fosse de Timor, tandis que celle de la zone économique exclusive a été
déterminée en fonction de la distance ; la première ligne est plus proche du
côté indonésien. En conséquence de ces deux accords, il existe plusieurs
496 delimitation of the continental shelf (sep. op. xue)
subjacent to Indonesia’s exclusive economic zone (see illustrative map 1,
p. 497). For the purpose of management, the Agreement contains a specific
provision regulating, inter alia, the rights and obligations of each party in
the areas of overlapping jurisdiction. It affirms Indonesia’s sovereign rights
of exclusive economic zone in the water column and Australia’s sovereign
rights of continental shelf in the seabed3. Although the Agreement has not
yet entered into force, it manifests that the parties did not consider there
existed a customary rule by which Australia could not, by law, claim its entitlement
to an extended continental shelf that extends within Indonesia’s
200 nautical miles from its baselines.
3 Article 7 of the Agreement reads as follows:
“Areas of overlapping jurisdiction
In those areas where the areas of exclusive economic zone adjacent to and appertaining
to a Party (the First Party) overlap the areas of seabed adjacent to and appertaining to a
Party being the other Party (the Second Party):
(a) the First Party may exercise exclusive economic zone sovereign rights and jurisdiction
provided for in the 1982 Convention in relation to the water column;
(b) the Second Party may exercise continental shelf sovereign rights and jurisdiction
provided for in the 1982 Convention in relation to the seabed;
(c) the construction of an artificial island shall be subject to the agreement of both Parties.
An ‘artificial island’ for the purposes of this Article is an area of land, surrounded by
water, which is above water at high tide by reason of human intervention;
(d) the Second Party shall give the First Party three months notice of the proposed grant
of exploration or exploitation rights;
(e) the construction of installations and structures shall be the subject of due notice and
a permanent means of giving warning of their presence must be maintained;
(f) (i) any installation or structure which is abandoned or disused shall be removed by
the Party which authorised its construction in order to ensure the safety of navigation,
taking into account any generally accepted international standards
established in this regard by the competent international organisation;
(ii) such removal shall also have due regard to fishing and to the protection of the
marine environment. Appropriate publicity shall be given to the depth, position
and dimensions of any installations or structures not entirely removed;
(g) the construction of a fish aggregating device shall be the subject of due notice;
(h) the Party constructing an artificial island, installation, structure or fish aggregating
device shall have exclusive jurisdiction over it;
(i) marine scientific research shall be carried out or authorised by a Party in accordance
with the 1982 Convention and such research shall be notified to the other Party;
(j) the Parties shall take effective measures as may be necessary to prevent, reduce and
control pollution of the marine environment;
(k) each Party shall be liable in accordance with international law for pollution of the
marine environment caused by activities under its jurisdiction;
(l) any island within the meaning of Article 121.1 of the 1982 Convention which emerges
after the entry into force of this Treaty shall be the subject of consultations between
the Parties with a view to determining its status;
délimitation du plateau continental (op. ind. xue) 496
zones de chevauchement où le plateau continental étendu de l’Australie est
sous-jacent à la zone économique exclusive de l’Indonésie (voir la carte no 1,
p. 497). Aux fins de gestion, l’accord contient une disposition particulière
qui réglemente, entre autres, les droits et obligations de chaque partie dans
les zones de juridiction concurrente. Il confirme que les droits relatifs à la
zone économique exclusive sont exercés souverainement par l’Indonésie sur
la colonne d’eau et que ceux relatifs au plateau continental sont exercés souverainement
par l’Australie sur les fonds marins3. Même s’il n’est pas encore
entré en vigueur, cet accord montre que les parties n’ont pas jugé qu’une
règle coutumière empêchait l’Australie, en droit, de revendiquer un plateau
continental étendu se prolongeant en deçà de 200 milles marins des lignes de
base indonésiennes.
3 L’article 7 de l’accord se lit comme suit :
« Zones de chevauchement de juridictions
Dans les zones où la zone économique exclusive adjacente à une Partie (la « première
Partie ») et relevant de celle-ci chevauche les fonds marins adjacents à une autre Partie (la
« seconde Partie ») et relevant de celle-ci :
a) la première Partie exerce sur la colonne d’eau les droits souverains et la juridiction
relatifs à la zone économique exclusive qui sont prévus par la convention de 1982 ;
b) la seconde Partie exerce sur les fonds marins les droits souverains et la juridiction
relatifs au plateau continental qui sont prévus par la convention de 1982 ;
c) toute construction d’une île artificielle est subordonnée à l’accord des deux Parties.
Une « île artificielle » au sens du présent article est une étendue de terre entourée
d’eau qui reste découverte à marée haute par intervention anthropique ;
d) la seconde Partie notifie à la première Partie, trois mois à l’avance, toute concession
de droits d’exploration ou d’exploitation envisagée ;
e) la construction d’installations et ouvrages doit être dûment notifiée et l’entretien de
moyens permanents pour signaler leur présence doit être assuré ;
f) i) les installations ou ouvrages abandonnés ou désaffectés sont enlevés par la Partie
qui en a autorisé la construction afin d’assurer la sécurité de la navigation, compte
tenu des normes internationales généralement acceptées et établies en la matière
par l’organisation internationale compétente ;
ii) il est procédé à l’enlèvement de ces installations ou ouvrages en tenant dûment
compte également de la pêche et de la protection du milieu marin. Une publicité
adéquate est donnée à la profondeur, à la position et aux dimensions des installations
ou ouvrages qui n’ont pas été complètement enlevés ;
g) la construction de dispositifs de concentration de poissons doit être dûment notifiée ;
h) la Partie qui construit une île artificielle, une installation, un ouvrage ou un dispositif
de concentration de poissons a juridiction exclusive sur cette île artificielle, cette
installation, cet ouvrage ou ce dispositif de concentration de poissons ;
i) une Partie conduit des activités de recherche scientifique marine, ou en autorise la
conduite, conformément à la Convention de 1982 et en donne notification à l’autre
Partie ;
j) les Parties prennent toutes les mesures qui sont nécessaires pour réduire, prévenir et
maîtriser efficacement la pollution du milieu marin ;
k) chaque Partie est responsable conformément au droit international de la pollution du
milieu marin causée par des activités relevant de la juridiction ;
l) toute île au sens du paragraphe 1 de l’article 121 de la Convention de 1982 qui émerge
après l’entrée en vigueur du présent Traité fait l’objet de consultations entre les
Parties aux fins de la détermination de son statut ;
497 delimitation of the continental shelf (sep. op. xue)
Illustrative Map 1
(Source: Department of State of the United States of America, “Limits in
the Seas (No. 141)  Indonesia: Archipelagic and other Maritime Claims and Boundaries”,
September 20144.)
(m) neither Party shall exercise its rights and jurisdiction in a manner which unduly
inhibits the exercise of the rights and jurisdiction of the other Party; and
(n) the Parties shall cooperate with each other in relation to the exercise of their respective
rights and jurisdiction.”
4 Available at https://www.state.gov/wp-content/uploads/2020/02/LIS-141.pdf, p. 12.
THAILAND t
Indonesia
Archipelagic Baseline Claim
and Maritime Boundaries Andaman Islands
.l
(INDIA)
BUR.􀀄􀀅 0
-
95° E
􀁃 Cocos
(Keeling) Islands
(AUST.)
100°1E
MBODIA
1
· 4e􀀃
I
QAM a --."~.
• X\\ (\ • , '.·...
. 1 • Boundary not in force.
•NG
•• - 0
. • !/ IN
􀀜 # - - - - PALAU L 5
= p Ak.. - •Q-
,,
• Baseline point
-- Archipel agic baseline
-- Indonesia-India (seat>ed)
-- Indonesia-Mal aysia (seabed) - - • Indonesia-Australia (EEZ)" /1􀀃1 -- Indonesia-Thailand (seabed) -- Indonesia-Australia (seabed)
125 250
-- Indonesia-Vietnam (seabed)
-- Indonesia-Papua New Guinea
- - • Indonesia-Philippines (EEZt
500 Nautical Miles
Christmas Island "'
(AUST.)
+
/ND/AN OCEAN
105°,E 110° E
BRUN•E I l: • ,_ ,, -.[--•􀀖e-/e--"b- es.. 􀀯•• 􀀆 PACIFIC OCEAN
+
A USTRA LIA
20° S
E 120° E 125' E 130• E 135· E 140' E
délimitation du plateau continental (op. ind. xue) 497
Carte aux fins d’illustration no 1
(Source : Département d’État américain, « Limits in the Seas (No. 141)  Indonesia:
Archipelagic and other Maritime Claims and Boundaries »,
septembre 20144.)
m) aucune Partie n’exerce ses droits et sa juridiction d’une manière susceptible d’entraver
indûment l’exercice par l’autre Partie de ses droits et de sa juridiction ; et
n) les Parties coopèrent mutuellement dans l’exercice de leurs droits et juridiction
respectifs. »
4 Peut être consulté à l’adresse suivante : https://www.state.gov/wp-content/uploads/2020/
02/LIS-141.pdf, p. 12.
THAILAND t
Indonesia
Archipelagic Baseline Claim
and Maritime Boundaries Andaman Islands
.l
(INDIA)
BUR.􀀄􀀅 0
-
95° E
􀁃 Cocos
(Keeling) Islands
(AUST.)
100°1E
MBODIA
1
· 4e􀀃
I
QAM a --."~.
• X\\ (\ • , '.·...
. 1 • Boundary not in force.
•NG
•• - 0
. • !/ IN
􀀜 # - - - - PALAU L 5
= p Ak.. - •Q-
,,
• Baseline point
-- Archipel agic baseline
-- Indonesia-India (seat>ed)
-- Indonesia-Mal aysia (seabed) - - • Indonesia-Australia (EEZ)" /1􀀃1 -- Indonesia-Thailand (seabed) -- Indonesia-Australia (seabed)
125 250
-- Indonesia-Vietnam (seabed)
-- Indonesia-Papua New Guinea
- - • Indonesia-Philippines (EEZt
500 Nautical Miles
Christmas Island "'
(AUST.)
+
/ND/AN OCEAN
105°,E 110° E
BRUN•E I l: • ,_ ,, -.[--•􀀖e-/e--"b- es.. 􀀯•• 􀀆 PACIFIC OCEAN
+
A USTRA LIA
20° S
E 120° E 125' E 130• E 135· E 140' E
498 delimitation of the continental shelf (sep. op. xue)
30. The agreement on maritime boundaries concluded between Australia
and Papua New Guinea is another example (Treaty between Australia and
the Independent State of Papua New Guinea concerning sovereignty and
maritime boundaries in the area between the two countries, including the
area known as Torres Strait, and related matters, concluded 18 December
1978, entered into force 15 February 1985, UNTS, Vol. 1429, p. 207). Under
Article 4 of this Treaty, two maritime boundaries are established between
the two States. The first line is the continental shelf boundary concerning
“seabed jurisdiction”, which is defined as “sovereign rights over the continental
shelf in accordance with international law, and includes jurisdiction
over low-tide elevations, and the right to exercise such jurisdiction in respect
of those elevations, in accordance with international law”5. The second line
is the boundary relating to fisheries jurisdiction, defined as “sovereign rights
or the purpose of exploring and exploiting, conserving and managing fisheries
resources other than sedentary species”6. Based on the co-ordinates of
the two boundaries, it is shown that, while the two boundaries in the eastern
and western sections coincide, the two boundaries are separate in the middle
section in the area known as the Torres Strait (see illustrative map 2, p. 499).
Papua New Guinea, like Indonesia, accepted Australia’s position without
any reservation. This treaty remains in force to date.
31. Australia reiterated its position on the natural prolongation criterion
during the Timor Sea Conciliation with Timor-Leste on the basis of Article
76, paragraph 1, of UNCLOS in light of the geological and
geomorphological situation of the Timor Trough in the Timor Sea (Timor-
Leste v. Australia, Permanent Court of Arbitration, Case Number 2016-10,
Opening Session Transcript, 29 August 2016, p. 91). Although the parties
ultimately reached a delimitation agreement establishing a single maritime
boundary for both the exclusive economic zone and the continental shelf, the
Preamble of the Treaty expressly states that “the settlement contained in this
Treaty is based on a mutual accommodation between the Parties without
prejudice to their respective legal positions” (Treaty between the Democratic
Republic of Timor-Leste and Australia establishing their maritime
boundaries in the Timor Sea, concluded 6 March 2018, entered into force
30 August 2019, Australian Treaty Series No. 16, 2019; emphasis added).
32. A more recent example is the delimitation agreement between Indonesia
and the Philippines concerning the delimitation of the exclusive
economic zone in the Celebes Sea concluded in 2014 (Agreement between
the Government of the Republic of Indonesia and the Government of the
Republic of the Philippines concerning the delimitation of the exclusive economic
zone boundary, concluded 23 May 2014, entered into force 1 August
2019, UNTS, Vol. 3324, p. 1). The distance between the parties in the area in
5 Article 1 (1) (i) and Article 4 (1).
6 Article 1 (1) (b) and Article 4 (2).
délimitation du plateau continental (op. ind. xue) 498
30. L’accord sur les frontières maritimes conclu par l’Australie et la
Papouasie-Nouvelle-Guinée est un autre exemple (traité relatif à la souveraineté
et aux frontières maritimes entre les deux pays, y compris dans la région
dénommée détroit de Torres, et à des questions connexes, conclu le
18 décembre 1978, entré en vigueur le 15 février 1985, RTNU, vol. 1429,
p. 207). L’article 4 de ce traité établit deux frontières maritimes entre les
deux États. La première ligne délimite le plateau continental en ce qui
concerne la « juridiction sur les fonds marins », définie comme désignant
« les droits souverains sur le plateau continental conformément au droit
international [et] compren[ant] la juridiction sur les [hauts-fonds découvrants]
ainsi que le droit d’exercer [ladite] juridiction … conformément au
droit international »5. La deuxième ligne délimite la juridiction en matière de
pêche, définie comme désignant « les droits souverains quant à la prospection,
l’exploitation, la conservation et l’aménagement des ressources
halieutiques autres que les espèces sédentaires »6. Les coordonnées des deux
frontières montrent que celles-ci, si elles coïncident sur les segments est
et ouest, s’écartent cependant l’une de l’autre dans leur partie centrale,
située dans la zone appelée détroit de Torres (voir la carte no 2, p. 499). La
Papouasie-Nouvelle-Guinée a, comme l’Indonésie, accepté sans réserve la
position de l’Australie. Ce traité est toujours en vigueur.
31. L’Australie a réaffirmé sa position concernant le critère du prolongement
naturel à l’occasion de la procédure de conciliation qui l’a opposée à la
République démocratique du Timor-Leste au sujet de la mer de Timor, en
invoquant le paragraphe 1 de l’article 76 de la CNUDM à la lumière de la
situation géologique et géomorphologique de la fosse de Timor (Timor-Leste
c. Australie, Cour permanente d’arbitrage, affaire no 2016-10, transcription
de la séance d’ouverture, 29 août 2016, p. 91). Si les parties sont finalement
parvenues à conclure un accord de délimitation qui établit une frontière
maritime unique à la fois pour la zone économique exclusive et pour le
plateau continental, elles ont toutefois expressément précisé dans le préambule
de cet instrument que « le règlement contenu dans le présent traité
repose sur un arrangement mutuel entre les Parties, sans préjudice de leurs
positions juridiques respectives » (traité entre la République démocratique
du Timor-Leste et l’Australie établissant leurs frontières maritimes dans la
mer de Timor, conclu le 6 mars 2018, entré en vigueur le 30 août 2019,
Australian Treaty Series no 16, 2019 ; les italiques sont de moi).
32. Un autre exemple récent est l’accord conclu en 2014 par l’Indonésie et
les Philippines pour délimiter leurs zones économiques exclusives en mer
des Célèbes (accord entre le Gouvernement de la République d’Indonésie et
le Gouvernement de la République des Philippines relatif à la délimitation
frontalière de la zone économique exclusive, conclu le 23 mai 2014, entré en
vigueur le 1er août 2019, RTNU, vol. 3324, p. 1). La distance entre les côtes de
ces deux États en mer des Célèbes est inférieure à 400 milles marins. En
5 Article 1, par. 1, al. i), et article 4, par. 1.
6 Article 1, par. 1, al. b), et article 4, par. 2.
499 delimitation of the continental shelf (sep. op. xue)
Illustrative Map 2
(Source: Department of Foreign Affairs and Trade of Australia,
“Guidelines for Traditional Visitors Travelling under the Torres Strait Treaty”7.)
7 Available at https://www.dfat.gov.au/geo/torres-strait/guidelines-for-traditional-visitorstravelling-
under-the-torres-strait-treaty.
!
!
!
!
!
!
!
!
!
!
!
!
!
!
144°30'E
144°30'E
144°0'E
144°0'E
143°30'E
143°30'E
143°0'E
143°0'E
142°30'E
142°30'E
142°0'E
142°0'E
141°30'E
141°30'E
9°0'S 9°0'S
9°30'S 9°30'S
10°0'S 10°0'S
10°30'S 10°30'S
Diagram produced by Geoscience Australia for the
Department of Foreign Affairs and Trade
This diagram is indicative only and is not to be used for navigation
GeoCat 71855
Australian Maritime Zones in the Torres Strait
Badu
Boigu
Poruma (Coconut Island)
Dauan
Erub (Darnley Island)
Kubin
St Pauls
Mabuiag
Mer (Murray Island)
Saibai
Ugar (Stephens Island)
Warraber (Sue Island)
Iama (Yam Island)
Masig (Yorke Island)
Bula
Mari
Jarai
Buzi/Berr
Sigabadaru
Mabadauan
Old Mawatta
Ture Ture
Kadawa
Katatai
Parama
Sui
0 5 10 20 km
Tais
! Thursday Island
! Daru
Treaty between Australia and the Independent
State of Papua New Guinea concerning Sovereignty and Maritime
Boundaries in the area between the two Countries, including the
area known as Torres Strait, and Related Matters
This diagram is not a legal document.
For precise boundaries please refer to the
Australian Treaty Series 1985 No. 4
Protected Zone
Seabed Jurisdiction Line
Fisheries Jurisdiction Line
Australian Territorial Sea
PNG Treaty Village
! Administrative Centres
Australian Treaty Community
délimitation du plateau continental (op. ind. xue) 499
Carte aux fins d’illustration no 2
(Source : Ministère australien des affaires étrangères et du commerce, « Guidelines for
Traditional Visitors Travelling under the Torres Strait Treaty »7.)
7 Peut être consulté à l’adresse suivante : https://www.dfat.gov.au/geo/torres-strait/
guidelines-for-traditional-visitors-travelling-under-the-torres-strait-treaty.
!
!
!
!
!
!
!
!
!
!
!
!
!
!
144°30'E
144°30'E
144°0'E
144°0'E
143°30'E
143°30'E
143°0'E
143°0'E
142°30'E
142°30'E
142°0'E
142°0'E
141°30'E
141°30'E
9°0'S 9°0'S
9°30'S 9°30'S
10°0'S 10°0'S
10°30'S 10°30'S
Diagram produced by Geoscience Australia for the
Department of Foreign Affairs and Trade
This diagram is indicative only and is not to be used for navigation
GeoCat 71855
Australian Maritime Zones in the Torres Strait
Badu
Boigu
Poruma (Coconut Island)
Dauan
Erub (Darnley Island)
Kubin
St Pauls
Mabuiag
Mer (Murray Island)
Saibai
Ugar (Stephens Island)
Warraber (Sue Island)
Iama (Yam Island)
Masig (Yorke Island)
Bula
Mari
Jarai
Buzi/Berr
Sigabadaru
Mabadauan
Old Mawatta
Ture Ture
Kadawa
Katatai
Parama
Sui
0 5 10 20 km
Tais
! Thursday Island
! Daru
Treaty between Australia and the Independent
State of Papua New Guinea concerning Sovereignty and Maritime
Boundaries in the area between the two Countries, including the
area known as Torres Strait, and Related Matters
This diagram is not a legal document.
For precise boundaries please refer to the
Australian Treaty Series 1985 No. 4
Protected Zone
Seabed Jurisdiction Line
Fisheries Jurisdiction Line
Australian Territorial Sea
PNG Treaty Village
! Administrative Centres
Australian Treaty Community
500 delimitation of the continental shelf (sep. op. xue)
the Celebes Sea is less than 400 nautical miles. In delimiting the boundary
of exclusive economic zones between the two States, the parties took account
of the provisions of UNCLOS and the principles applicable to delimitation.
The Agreement specifically provides that “[t]his Agreement shall not prejudice
any rights or positions of the Contracting Parties with regard to the
delimitation of the Continental Shelf boundary”8. Apparently, the parties to
the Agreement do not consider that the boundary of the exclusive economic
zone is decisive for the delimitation of the continental shelf boundary within
200 nautical miles.
33. Similar practice can also be found in other regions. Denmark and the
United Kingdom, for instance, reached an agreement on the maritime delimitation
in the area between the Faroe Islands and the United Kingdom in
1999 (Agreement between the Government of the Kingdom of Denmark
together with the Home Government of the Faroe Islands, on the one hand,
and the Government of the United Kingdom of Great Britain and Northern
Ireland, on the other hand, relating to the Maritime Delimitation in the area
between the Faroe Islands and the United Kingdom, concluded 18 May 1999,
entered into force 21 July 1999, United Kingdom Treaty Series (UKTS),
1999, No. 76). Under the Agreement, the parties delimited the continental
shelf in the area and the waters superjacent to the continental shelf in part of
the area and established a special régime, called “the Special Area”, in the
remaining part. The parties made special arrangements for the exercise of
fisheries jurisdiction and rights in the Special Area. In a subsequent protocol
concluded in 2012 to the Agreement, the parties established exclusive economic
zones in the waters as previously delimited and decided to retain the
previous boundaries and the Special Area as drawn in the Agreement (UKTS,
2014, No. 22). From the maritime boundary shown in illustrative map 3
reproduced below (p. 501), one can see that the Special Area as a water column
is separated from the continental shelf of either party.
34. There are other bilateral maritime delimitation agreements, where one
party’s extended continental shelf overlaps with the exclusive economic
zone of another party (see Agreement between the United States of America
and the Union of Soviet Socialist Republics on the maritime boundary, concluded
1 June 1990, applied provisionally since 1 June 1990, Law of the Sea
Bulletin, No. 17, April 1991, p. 15; Treaty between the Kingdom of Norway
and the Russian Federation concerning maritime delimitation and cooperation
in the Barents Sea and the Arctic Ocean, concluded 15 September 2010,
entered into force 7 July 2011, Law of the Sea Bulletin, No. 77, 2012, p. 24)9.
8 Article 1, paragraph 3, of the Agreement.
9 In the Agreement between the United States of America and the Union of Soviet Socialist
Republics on the Maritime Delimitation, the boundary line as determined results in two areas,
so-called “special areas”, in which one party’s exclusive economic zone is superjacent to the
continental shelf of the other party. Pursuant to Article 3, each party permits the other party to
exercise “the sovereign rights and jurisdiction derived from exclusive economic zone jurisdiction”
that the other party would otherwise be entitled to exercise under international law. To
délimitation du plateau continental (op. ind. xue) 500
traçant la frontière entre leurs zones économiques exclusives, les parties ont
tenu compte des dispositions de la CNUDM et des principes applicables à la
délimitation. Leur accord précise explicitement qu’il « ne porte pas atteinte
aux droits ni aux positions des Parties contractantes en ce qui concerne la
délimitation du plateau continental »8. Manifestement, l’Indonésie et les Philippines
n’ont pas jugé que la frontière de la zone économique exclusive fût
décisive pour la délimitation du plateau continental dans la limite de
200 milles marins.
33. Des pratiques similaires existent également dans d’autres régions du
monde. Le Danemark et le Royaume-Uni, par exemple, ont conclu en 1999 un
accord pour délimiter la zone située entre les îles Féroé et le Royaume-Uni
(accord entre le Gouvernement du Royaume de Danemark, agissant conjointement
avec le Gouvernement local des îles Féroé, d’une part, et le Gouvernement
du Royaume-Uni de Grande-Bretagne et d’Irlande du Nord, d’autre part,
concernant la délimitation maritime de la zone située entre les îles Féroé et le
Royaume-Uni, conclu le 18 mai 1999, entré en vigueur le 21 juillet 1999,
United Kingdom Treaty Series (UKTS), 1999, no 76). Par cet accord, les parties
ont délimité le plateau continental dans la zone concernée ainsi que les eaux
sus-jacentes au plateau continental dans une portion de cette zone, et ont établi
un régime spécial dans la portion restante, appelée « zone spéciale ». Elles ont
défini des modalités particulières pour l’exercice de la compétence en matière
de pêcheries et des droits de pêche dans la zone spéciale. Par un protocole
ultérieur conclu en 2012, elles ont créé des zones économiques exclusives
dans les espaces précédemment délimités, en choisissant de conserver les
frontières antérieures et la zone spéciale telles que tracées dans l’accord
(UKTS, 2014, no 22). La frontière maritime illustrée sur la carte no 3 reproduite
ci-après (p. 501) montre que la zone spéciale, en tant que colonne d’eau,
ne fait pas partie du plateau continental de l’une ou l’autre des parties.
34. D’autres accords bilatéraux consacrent une délimitation maritime par
laquelle le plateau continental étendu d’une partie chevauche la zone économique
exclusive d’une autre partie (voir accord entre les États-Unis
d’Amérique et l’Union des républiques socialistes soviétiques relatif au tracé
de la frontière maritime entre les deux pays, conclu le 1er juin 1990 et appliqué
provisoirement depuis cette date, Bulletin du droit de la mer, no 17, avril
1991, p. 15 ; traité entre le Royaume de Norvège et la Fédération de Russie
relatif à la délimitation maritime et la coopération dans la mer de Barents et
l’océan Arctique, conclu le 15 septembre 2010, entré en vigueur le 7 juillet
2011, Bulletin du droit de la mer, no 77, 2012, p. 24)9.
8 Article premier, par. 3.
9 Dans l’accord entre les États-Unis d’Amérique et l’Union des républiques socialistes
soviétiques relatif au tracé de la frontière maritime entre les deux pays, la ligne de délimitation
telle qu’elle a été tracée a créé deux zones dites « spéciales », dans lesquelles la zone économique
exclusive (ZEE) d’une des parties est sus-jacente au plateau continental de l’autre
partie. Aux termes de l’article 3, chacune des parties permet à l’autre d’exercer les « droits
souverains et [les] prérogatives qui sont les attributs de la juridiction sur la zone économique
501 delimitation of the continental shelf (sep. op. xue)
Illustrative Map 3
(Source: Jonathan I. Charney and Robert W. Smith (eds.),
International Maritime Boundaries, 2002, Vol. IV, p. 2955.)
délimitation du plateau continental (op. ind. xue) 501
Carte aux fins d’illustration no 3
(Source : Jonathan I. Charney et Robert W. Smith (sous la dir. de),
International Maritime Boundaries, 2002, vol. IV, p. 2955.)
502 delimitation of the continental shelf (sep. op. xue)
35. In support of its claim, the Respondent refers to Article 2, paragraph 3,
of the Treaty between the Federated States of Micronesia and the Republic
of Palau concerning maritime boundaries and cooperation on related matters,
which provides that “no Party shall claim an extended continental shelf
that intrudes into the Exclusive Economic Zone . . . of the other Party” (concluded
16 July 2006, entered into force 16 February 2016, UNTS, Vol. 3210,
p. 1). This evidence, contrary to the position of the Respondent, proves that
these two States do not consider that there is a customary rule that prohibits
an extended continental shelf from extending within 200 nautical miles from
the coast of another State, because otherwise such a clause would be unnecessary.
36. Admittedly, States may make special arrangements through bilateral
agreements, not necessarily guided by generally applicable law. Nonetheless,
such practice supports the settled jurisprudence that the régimes of the
exclusive economic zone and of the continental shelf, though interrelated,
are distinct and may be delimited separately. Although a single maritime
boundary is generally preferred for the convenience of management, that
rationale for the delimitation does not have a restrictive effect on the entitlement
to the extended continental shelf.
C. State Practice with regard to CLCS Submissions
37. With regard to the submissions of States to the CLCS, the Court notes
that the vast majority of States parties to the Convention that have made submissions
to the CLCS have chosen not to assert therein limits that extend
within 200 nautical miles from the baselines of another State. Without any
examination of the submissions of the “vast majority of [those] States”, the
Court considers that “the practice of States before the CLCS is indicative of
opinio juris, even if such practice may have been motivated in part by considerations
other than a sense of legal obligation” (Judgment, para. 77).
Recalling some inconsistent practice of “a small number of States”, the
Court takes the view that, “[t]aken as a whole, the practice of States may be
considered sufficiently widespread and uniform for the purpose of the idenput
it in more simple terms, they transfer their EEZ rights to each other without changing the
maritime title of the respective areas. In the Treaty between the Kingdom of Norway and the
Russian Federation concerning Maritime Delimitation and Cooperation in the Barents Sea and
the Arctic Ocean, the maritime boundary line also produces a “Special Area” which lies
within 200 nautical miles of Norway and beyond 200 nautical miles of the Russian Federation.
Article 3 of the Treaty provides that the Russian Federation shall be entitled to exercise EEZ
rights and jurisdiction that Norway would otherwise be entitled to exercise under international
law. It also provides, however, that the Russian Federation’s exercise of such rights and jurisdiction
“derives from the agreement of the parties and does not constitute an extension of its
exclusive economic zone” (emphasis added). Legally speaking, therefore, the Russian Federation’s
extended continental shelf is subjacent to the exclusive economic zone of Norway.
délimitation du plateau continental (op. ind. xue) 502
35. À l’appui de ses arguments, la Colombie avait cité le paragraphe 3 de
l’article 2 du traité entre les États fédérés de Micronésie et la République des
Palaos relatif aux frontières maritimes et à la coopération dans les matières
connexes, qui dispose qu’« aucune Partie ne peut revendiquer un plateau
continental élargi qui empiète sur la zone économique exclusive … de l’autre
Partie » (conclu le 16 juillet 2006, entré en vigueur le 16 février 2016, RTNU,
vol. 3210, p. 1). Or, contrairement à ce que la défenderesse croit ainsi démontrer,
cela prouve que pour ces deux États aucune règle coutumière n’interdisait
que le plateau continental étendu d’un État se prolonge à moins de 200 milles
marins des côtes d’un autre État, car si tel était le cas, cette clause serait
inutile.
36. Certes, les États peuvent convenir de dispositions spéciales par des
accords bilatéraux, sans suivre nécessairement le droit généralement applicable.
Néanmoins, cette pratique confirme la jurisprudence constante selon
laquelle les régimes de la zone économique exclusive et du plateau continental,
bien qu’interdépendants, sont distincts et peuvent être délimités
séparément. Même si la solution d’une frontière maritime unique est généralement
privilégiée pour faciliter la gestion, ce qui se justifie aux fins de la
délimitation n’a pas d’effet restrictif sur le droit à un plateau continental
étendu.
C. La pratique des États devant la Commission des limites
37. Au sujet des demandes des États à la Commission des limites, la Cour
note que la grande majorité des États parties à la CNUDM qui ont présenté
de telles demandes ont choisi de ne pas y revendiquer des limites situées à
moins de 200 milles marins des lignes de base d’un autre État. Sans examiner
les demandes de cette « grande majorité », elle constate que « la pratique
des États devant la Commission révèle l’existence d’une opinio juris, même
si cette pratique a pu être motivée en partie par des considérations autres
qu’un sentiment d’obligation juridique » (arrêt, par. 77). Rappelant néanmoins
qu’« un petit nombre d’États » a agi autrement, elle conclut que, « [p]rise
dans son ensemble, la pratique des États peut être considérée comme
suffisamment répandue et uniforme aux fins de l’identification du droit interexclusive
» qu’elle-même serait autrement en droit d’exercer en vertu du droit international.
Pour le dire plus simplement, les parties transfèrent l’une à l’autre leurs droits sur les ZEE sans
changer le titre maritime des zones en question. Dans le traité entre le Royaume de Norvège et
la Fédération de Russie relatif à la délimitation maritime et la coopération dans la mer de
Barents et l’océan Arctique, la ligne de délimitation maritime produit également une « zone
spéciale » située à moins de 200 milles marins des côtes norvégiennes et à plus de 200 milles
marins des côtes russes. L’article 3 du traité dispose que la Fédération de Russie peut exercer
les droits et la juridiction relatifs à la ZEE que la Norvège aurait pu exercer en vertu du droit
international. Cependant, il dit également que l’exercice par la Fédération de Russie de ces
droits et de cette juridiction « ne dériv[e] que de l’accord des Parties et ne saurai[t] être considér[
é] comme une extension de sa zone économique exclusive » (les italiques sont de moi). Du
point de vue juridique, par conséquent, le plateau continental étendu russe est sous-jacent à la
ZEE norvégienne.
503 delimitation of the continental shelf (sep. op. xue)
tification of customary international law”. It further states that, given its
extent over a long period of time, this State practice may be seen as an
expression of opinio juris (ibid.). This is a rather loose statement on the practice
of States. The Court did not even bother to address exactly what practice
amounts to an expression of opinio juris.
38. First of all, it is necessary to examine the character of the State submissions
to the CLCS. Article 76, paragraph 10, of UNCLOS states that “[t]he
provisions of this article are without prejudice to the question of delimitation
of the continental shelf between States with opposite or adjacent coasts”.
Accordingly, the claim that a State has made in its submission to the CLCS
may not be final and binding on its position with regard to the questions of
entitlement and delimitation; a State may leave out a certain portion of its
claim in its submission if it deems it necessary, which does not affect that
State’s position in the delimitation. This understanding is supported by the
terms of the CLCS’s mandate and State practice. Pursuant to Rule 46 of the
Rules of Procedure of the CLCS and paragraph 5 (a) of Annex I to the Rules
of Procedure, in the case where a land or maritime dispute exists, the Commission
shall not consider and qualify a submission made by any of the
States concerned in the dispute, unless prior consent is given by all the parties
to the dispute. Understandably, in order to have their submissions
considered and qualified by the Commission, States may refrain from
extending their continental shelf entitlement within 200 nautical miles from
the coast of other States with a view to avoiding a dispute. Such restraint
may be exercised because of an agreement of the States concerned, a prior
unilateral commitment, or a special arrangement. Some States have made
several submissions to the CLCS in respect of their separate territorial areas.
Their claims to an extended continental shelf with respect to those areas do
not consistently refrain from encroaching upon the 200-nautical-mile entitlement
of another State. For instance, France’s submissions in respect of the areas
of French Guiana and New Caledonia and in respect of French Polynesia
stop at 200 nautical miles from the coasts of neighbouring States, but its submission
concerning Saint Pierre and Miquelon extends within 200 nautical
miles from the coast of Canada. When Canada raised its objection to the
latter submission on the ground that the maritime zones of Saint Pierre and
Miquelon had been definitely settled by arbitration, France maintained that
the arbitral tribunal declared that the question (of an entitlement to a continental
shelf beyond 200 nautical miles) did not fall within its competence.
It further underscored that “those claims do not run counter to the United
Nations Convention on the Law of the Sea or any rule of international law”
(Note Verbale from the Permanent Mission of France to the United Nations,
dated 17 December 2014; emphasis added). Evidently, no consistent State
practice can be identified from States’ submissions to the CLCS.
délimitation du plateau continental (op. ind. xue) 503
national coutumier ». La Cour ajoute que, étant donné son ampleur sur une
longue période, cette pratique étatique peut être considérée comme l’expression
de l’opinio juris (ibid.). C’est là une déclaration plutôt vague. La Cour ne
prend même pas la peine de préciser quelle pratique constitue une expression
de l’opinio juris.
38. La première chose à faire est d’examiner la nature des demandes des
États à la Commission des limites. Le paragraphe 10 de l’article 76 de la
CNUDM précise que ledit article « ne préjuge pas de la question de la délimitation
du plateau continental entre des États dont les côtes sont adjacentes ou
se font face ». Par conséquent, la revendication qu’un État présente à la Commission
peut ne pas être définitive et contraignante s’agissant de sa position
sur les questions de droits et de délimitation ; un État peut ne pas formuler la
totalité de sa revendication s’il le juge nécessaire, sans que cela n’ait d’incidence
sur sa position quant à la délimitation. Cette interprétation trouve
confirmation dans le mandat de la Commission elle-même ainsi que dans la
pratique des États. Conformément à l’article 46 de son règlement intérieur et
au paragraphe 5 a) de l’annexe I y afférente, lorsqu’il existe un différend terrestre
ou maritime, la Commission des limites ne peut pas examiner la demande
d’un État partie à ce différend, ni a fortiori se prononcer à son sujet, sauf
avec l’accord préalable de tous les autres États parties au différend. L’on
comprend dès lors que les États, pour s’assurer que la Commission examinera
leur demande et se prononcera à son sujet, s’abstiennent de revendiquer un
plateau continental étendu jusqu’à moins de 200 milles marins des côtes
d’autres États, afin d’éviter un différend. Une abstention peut s’expliquer par
un accord entre les intéressés, un engagement unilatéral antérieur ou
un arrangement particulier. Il arrive qu’un État saisisse la Commission de
plusieurs demandes concernant ses différentes zones territoriales. Les États
ne s’abstiennent pas systématiquement de demander une extension de leur
plateau continental qui empiéterait sur la zone de 200 milles marins d’un
autre État. Par exemple, le plateau continental revendiqué par la France pour
les zones de la Guyane française et de la Nouvelle-Calédonie, et pour la Polynésie
française, respectivement, s’arrête à 200 milles marins des côtes des
États voisins, mais celui qu’elle revendique pour Saint-Pierre-et-Miquelon
s’étend jusqu’à moins de 200 milles marins des côtes canadiennes. Lorsque le
Canada a objecté à cette dernière demande au motif que le sort des espaces
maritimes de Saint-Pierre-et-Miquelon avait été définitivement réglé par voie
d’arbitrage, la France a répondu que le tribunal arbitral avait réservé la question
(d’un plateau continental au-delà de 200 milles marins) comme ne
relevant pas de sa compétence. Elle a également souligné que « ces revendications
[n’étaient] contraires ni à la Convention des Nations Unies sur le
droit de la mer, ni à aucune règle de droit international » (note verbale en
date du 17 décembre 2014 adressée au Secrétaire général par la mission permanente
de la France auprès de l’Organisation des Nations Unies ; les italiques
sont de moi). À l’évidence, les demandes des États à la Commission des
limites ne font apparaître aucune pratique étatique uniforme.
504 delimitation of the continental shelf (sep. op. xue)
39. When the Court affirms the practice of the “vast majority of States parties”
for the determination of the customary rule, it primarily relies on the
93 submissions from 73 States and the Cook Islands received by the CLCS
so far. According to Colombia, among those 93 submissions, 38 do not reach
the 200-nautical-mile limit of another States and, therefore, are irrelevant.
Of the remaining 55 submissions, 51 are said by Colombia to have chosen
not to extend the continental shelf within 200 nautical miles from the coast
of other States; in its view, only four States have made the claim encroaching
upon the entitlement within 200 nautical miles of another State10. At first
sight, this looks overwhelmingly persuasive. For the purpose of the present
case, however, that practice obviously needs further scrutiny.
40. Notwithstanding Article 76, paragraph 10, of UNCLOS and the
above-mentioned CLCS rules, studies show that the practice of States is not
as certain and consistent as is suggested. Individually, almost one third of
the States that are said to have chosen not to claim their extended continental
shelf within 200 nautical miles of another State have already concluded
bilateral agreements with their neighbouring States on maritime delimitation
within 200 nautical miles. That fact may have a direct bearing on the
States’ decision to exercise restraint in their CLCS submissions. Moreover,
as mentioned above, some of the said States have indeed claimed an extended
continental shelf that extends within 200 nautical miles from the baselines of
another State in the delimitation. In this regard, the most illustrative example
is the recent case between Mauritius and the Maldives.
41. In the Mauritius/Maldives case before an ITLOS Special Chamber, the
Maldives claims an extended continental shelf that extends within 200 nautical
miles from the baselines of the Chagos Archipelago (Mauritius). While
this is not immediately apparent from the publicly available Executive Summary
of July 2010 of the Maldives’ Submission to the CLCS and the
accompanying maps, the ITLOS Special Chamber noted the existence of
such an overlap (Dispute concerning Delimitation of the Maritime Boundary
between Mauritius and Maldives in the Indian Ocean (Mauritius/Maldives),
Preliminary Objections, Judgment of 28 January 2021, para. 332; Dispute
concerning Delimitation of the Maritime Boundary between Mauritius and
Maldives in the Indian Ocean (Mauritius/Maldives), Judgment of 28 April
2023, para. 257). The Maldives itself “confirm[ed] its position that the Maldives’
entitlement to the continental shelf beyond 200 nautical miles from its
baseline can be . . . extended [within the 200-nautical-mile limit of Mauritius]”
(ITLOS/PV.22/C.28/4/Rev.1, p. 7). Mauritius claimed that the Maldives
cannot extend its continental shelf into the exclusive economic zone of Mauritius,
because it had undertaken a specific commitment not to do so (Dispute
concerning Delimitation of the Maritime Boundary between Mauritius and
10 These four States include China, the Republic of Korea, Nicaragua and Somalia.
délimitation du plateau continental (op. ind. xue) 504
39. Lorsqu’elle invoque la pratique de la « grande majorité des États parties
» pour déterminer la règle coutumière, la Cour s’appuie principalement
sur les 93 demandes, émanant de 73 États et des Îles Cook, dont la Commission
des limites a été saisie à ce jour. La Colombie fait valoir que, sur ces
93 demandes, 38 ne concernent pas un plateau continental atteignant la
limite des 200 milles marins d’autres États et ne sont donc pas pertinentes,
et que, dans 51 des 55 restantes, l’État concerné a choisi de ne pas étendre
son plateau continental en deçà de 200 milles marins des côtes d’autres
États ; selon elle, seuls quatre États ont revendiqué un plateau continental
empiétant sur la zone de 200 milles marins d’un autre État10. À première vue,
cela semble extrêmement convaincant. Cependant, aux fins de la présente
affaire, cette pratique doit à l’évidence être examinée plus attentivement.
40. Nonobstant les dispositions susmentionnées du paragraphe 10 de l’article
76 de la CNUDM et du règlement intérieur de la Commission des limites,
des études montrent que la pratique des États n’est pas aussi confirmée et uniforme
qu’il y paraît. Près d’un tiers des États qui auraient choisi de ne pas
situer les limites de leur plateau continental étendu à moins de 200 milles
marins des côtes d’un autre État avaient, individuellement, déjà conclu avec
leurs voisins des accords bilatéraux sur la délimitation maritime en deçà de
200 milles marins. C’est là un élément qui a pu influer directement la décision
de ces États de faire preuve de retenue dans leurs demandes à la Commission.
En outre, comme il a été dit plus haut, certains ont bel et bien revendiqué un
plateau continental étendu se prolongeant en deçà de 200 milles marins des
lignes de base d’un autre État dans le cadre de la délimitation. À cet égard,
l’exemple le plus parlant est la récente affaire entre Maurice et les Maldives.
41. Dans l’affaire Maurice/Maldives portée devant une chambre spéciale du
TIDM, les Maldives revendiquaient un plateau continental étendu se prolongeant
en deçà de 200 milles marins des lignes de base de l’archipel des Chagos
(Maurice). La Chambre spéciale a noté l’existence de ce chevauchement,
même si celui-ci n’était pas mis en évidence dans le résumé de la demande des
Maldives à la Commission des limites, en date de juillet 2010, ou sur les
cartes y afférentes, qui sont publiquement disponibles (Différend relatif à la
délimitation de la frontière maritime entre Maurice et les Maldives dans
l’océan Indien (Maurice/Maldives), exceptions préliminaires, arrêt du
28 janvier 2021, par. 332 ; Différend relatif à la délimitation de la frontière
maritime entre Maurice et les Maldives dans l’océan Indien (Maurice/
Maldives), arrêt du 28 avril 2023, par. 257). Les Maldives ont confirmé « leur
position selon laquelle … le plateau continental [auquel elles pouvaient prétendre]
au-delà de 200 [milles marins] de [leur] ligne de base p[ouvai]t être
prolongé [dans la limite des 200 milles marins de Maurice] » (TIDM/PV.22/
A28/4/Rev.1, p. 8). Maurice affirmait pour sa part que les Maldives ne pouvaient
pas étendre leur plateau continental jusque dans sa zone économique
exclusive car elles s’étaient expressément engagées à ne pas le faire (Diffé-
10 Ces quatre États sont la Chine, la République de Corée, le Nicaragua et la Somalie.
505 delimitation of the continental shelf (sep. op. xue)
Maldives in the Indian Ocean (Mauritius/Maldives), Judgment of 28 April
2023, para. 260). Indeed, Mauritius itself contended that,
“if Maldives were entitled to claim an outer continental shelf within
200 Miles of the baselines of Mauritius, so too could Mauritius, correspondingly,
claim an outer continental shelf that encroaches within
200 Miles of Maldives” (ITLOS/PV.22/C28/6/Rev.1, p. 29).
Ultimately, for reasons concerning the circumstances of that case, the
Special Chamber considered that it was
“not required to address the question whether the Maldives has an entitlement
to a continental shelf beyond 200 nm in the relevant area or the
question whether the Maldives’ entitlement to a continental shelf beyond
200 nm may extend within the 200 nm limit of Mauritius” (Dispute concerning
Delimitation of the Maritime Boundary between Mauritius and
Maldives in the Indian Ocean (Mauritius/Maldives), Judgment of
28 April 2023, para. 275).
The practice of both Mauritius and the Maldives in relation to the latter’s
extended continental shelf reduces the weight of the evidence presented by
Colombia. The Maldives’ “restraint” is not based on a legal obligation
derived from a customary rule, nor is Mauritius’s objection to the submission
of the Maldives to the CLCS based on customary international law.
42. Responses to the submissions of the four States that are said by Colombia
to have encroached on the 200-nautical-mile entitlements of other States
are also worth noting. In its communications sent to the United Nations
in response to the submissions of China and the Republic of Korea to the
CLCS, Japan, while objecting to the submissions, emphasized the need for
delimitation between the States concerned. With regard to China, Japan
states that
“[t]he distance between the opposite coasts of Japan and the People’s
Republic of China in the area with regard to the submission is less than
400 nautical miles[.] The delimitation of the continental shelf in this area
shall be effected by agreement between the States concerned in accordance
with Article 83 of the United Nations Convention on the Law of the
Sea (hereinafter referred to as ‘the Convention’). It is, thus, indisputable
that the People’s Republic of China cannot unilaterally establish the
outer limits of the continental shelf in this area.” (Note Verbale from the
Permanent Mission of Japan to the United Nations, dated 28 December
2012.)
délimitation du plateau continental (op. ind. xue) 505
rend relatif à la délimitation de la frontière maritime entre Maurice et les
Maldives dans l’océan Indien (Maurice/Maldives), arrêt du 28 avril 2023,
par. 260). Elle faisait d’ailleurs valoir que,
« si les Maldives étaient en droit de revendiquer un plateau continental
extérieur en deçà des 200 [milles marins] des lignes de base de Maurice,
alors Maurice aussi pou[v]ait à son tour revendiquer un plateau continental
extérieur empiétant [sur les] 200 [milles marins] de[s] Maldives »
(TIDM/PV.22/A28/6/Rev.1, p. 32).
Finalement, pour des raisons tenant aux circonstances de l’affaire, la
Chambre spéciale a considéré qu’elle n’était pas
« tenue de se prononcer sur la question de savoir si les Maldives [avaie]nt
un titre sur un plateau continental au-delà de 200 [milles marins] dans la
zone concernée, ni sur la question de savoir si le titre des Maldives sur
un plateau continental au-delà de 200 [milles marins] p[ouvai]t se prolonger
dans la limite des 200 [milles marins] de Maurice » (Différend
relatif à la délimitation de la frontière maritime entre Maurice et les
Maldives dans l’océan Indien (Maurice/Maldives), arrêt du 28 avril
2023, par. 275).
La pratique suivie tant par Maurice que par les Maldives s’agissant du plateau
continental étendu de ces dernières prive d’un certain poids les preuves invoquées
par la Colombie. La « retenue » dont faisaient preuve les Maldives
n’était pas fondée sur une obligation juridique découlant d’une règle coutumière,
pas plus que l’objection opposée par Maurice à leur demande devant la
Commission des limites n’était fondée sur le droit international coutumier.
42. Les réactions aux demandes des quatre États ayant choisi, selon la Colombie,
d’empiéter sur les zones de 200 milles marins d’autres États, sont
également intéressantes. Dans ses communications adressées aux Nations
Unies au sujet des demandes dont la Chine et la République de Corée ont saisi
la Commission des limites, le Japon, tout en s’opposant à ces demandes, a souligné
la nécessité d’une délimitation entre les États concernés. En ce qui
concerne la Chine, il a ainsi déclaré que
« [l]a distance séparant les côtes opposées du Japon et de la République
populaire de Chine dans la région concernée par la demande est inférieure
à 400 milles nautiques[.] Dans cette région, les limites du plateau
continental doivent faire l’objet d’un accord entre les États, conformément
à l’article 83 de la Convention des Nations Unies sur le droit de la
mer (ci-après dénommée “la Convention”). Il est donc indiscutable que
la République populaire de Chine ne peut décider unilatéralement des
limites extérieures du plateau continental dans cette région. » (Note verbale
en date du 28 décembre 2012 adressée au Secrétaire général par la
mission permanente du Japon auprès de l’Organisation des Nations
Unies.)
506 delimitation of the continental shelf (sep. op. xue)
43. Japan made a similar response to the submission by the Republic of
Korea. In its reply to Japan’s objection, the Republic of Korea stated the
following:
“Nothing in the text of the United Nations Convention on the Law of the
Sea (hereinafter referred to as ‘the Convention’) supports the suggestion
that the establishment of the outer limits of the continental shelf beyond
200 nautical miles in an area where the distance between States with
opposite coasts is less than 400 nautical miles cannot be accomplished
under the provisions of the Convention. The Convention establishes two
distinct bases of entitlement in the continental shelf: (1) distance from
the coast; and (2) the geomorphological criteria stated in paragraph 4 of
Article 76. Neither basis is afforded priority over the other under the Convention.
Japan, therefore, cannot use its entitlement based on the distance
criterion to negate Korea’s entitlement based on geomorphological
considerations, or to block the Commission from issuing recommendations
with regard to the existence and limits of the continental shelf in the
East China Sea. Accordingly, the Partial Submission of the Government
of the Republic of Korea to the Commission constitutes a legitimate
undertaking in conformity with and in satisfaction of its obligations under
the Convention, as well as the relevant provisions of the Rules of Procedures
and the Scientific and Technical Guidelines of the Commission.”
(Note Verbale from the Permanent Mission of the Republic of Korea to
the United Nations, dated 23 January 2013; emphasis added.)
44. In the case of Somalia, Somalia in its 2014 submission claimed that
there was an overlap between Somali and Yemeni claims as regards the areas
of the continental shelf beyond 200 nautical miles and that the delimitation
of the continental shelf between the two countries had not yet been resolved.
It indicated that it was ready to enter into consultation with Yemen with a
view to reaching an agreement or understanding which would allow the
Commission to consider and make recommendations on submissions by
each of the two coastal States. In its communication to the Secretary-
General, Yemen first objected to the consideration by the CLCS of Somalia’s
submission (Note Verbale from the Permanent Mission of the Republic of
Yemen to the United Nations, dated 10 December 2014). Somalia amended
its submission in 2015, which resulted in an overlap of its claim with part of
Yemen’s entitlements within 200 nautical miles from the coast of Yemen.
Afterwards, Yemen, while reaffirming that there was no agreement or understanding
between the two States regarding the potential overlap of maritime
zones beyond 200 nautical miles, indicated that
“in the interests of advancing the establishments of maritime limits for
itself and its neighbours in the Northwest Indian Ocean, it proposes to
remove its objection to the Article 76 submission by the Federal Governdélimitation
du plateau continental (op. ind. xue) 506
43. Le Japon a fait une déclaration similaire au sujet de la demande de
la République de Corée, laquelle a répondu en ces termes à son objection :
« Rien dans le texte de la Convention des Nations Unies sur le droit de
la mer … n’étaye l’idée selon laquelle il n’est pas possible, aux termes de
ses dispositions, d’établir les limites externes du plateau continental
au-delà de la ligne des 200 milles marins dans une zone où la distance
entre deux États qui se font face est inférieure à 400 milles marins. Aux
termes de la Convention, les droits exercés sur le plateau continental
reposent sur deux éléments distincts : 1) la distance à partir de la côte ; et
2) les données géomorphologiques établies au paragraphe 4 de l’article
76. Les deux éléments ont autant de poids l’un que l’autre. Le Japon
ne saurait donc se prévaloir du critère lié à la distance pour méconnaître
le droit dont jouit la Corée en vertu des données géomorphologiques, ni
pour empêcher la Commission de formuler des recommandations
concernant l’existence et les limites du plateau continental dans la mer
de Chine orientale. Par conséquent, la demande partielle est légitime et,
en la présentant, la République de Corée s’est acquittée des obligations
que lui imposaient la Convention ainsi que les dispositions pertinentes
des Directives scientifiques et techniques de la Commission. » (Note
verbale en date du 23 janvier 2013 adressée au Secrétaire général par la
mission permanente de la République de Corée auprès de l’Organisation
des Nations Unies ; les italiques sont de moi.)
44. La Somalie affirmait quant à elle, dans sa demande de 2014 à la Commission
des limites, qu’il y avait chevauchement entre ses prétentions et
celles du Yémen sur les zones du plateau continental situées au-delà de
200 milles marins, et que la question de la délimitation du plateau continental
entre les deux pays n’était pas encore résolue. Elle se déclarait prête à
mener des consultations avec le Yémen en vue de parvenir à un accord ou à
une entente qui permettrait à la Commission d’examiner les demandes présentées
par chacun des deux États côtiers et de formuler des recommandations
à leur sujet. Dans une communication au Secrétaire général, le Yémen a
d’abord fait objection à l’examen de la demande somalienne par la Commission
(note verbale en date du 10 décembre 2014 adressée au Secrétaire
général par la mission permanente de la République du Yémen auprès de
l’Organisation des Nations Unies). La Somalie a modifié sa demande en
2015, de telle sorte que les espaces maritimes qu’elle revendiquait chevauchaient
une partie de ceux auxquels le Yémen avait droit sur 200 milles
marins à partir de ses côtes. Le Yémen, tout en réaffirmant qu’il n’y avait pas
d’accord ou d’entente entre les deux États sur un éventuel chevauchement des
espaces maritimes au-delà de 200 milles marins, a alors fait savoir que,
« soucieux de faire avancer, dans l’intérêt de ses voisins et de lui-même,
l’établissement des limites maritimes dans le nord-ouest de l’océan
Indien, il se propos[ait] de lever son objection à la demande présentée
507 delimitation of the continental shelf (sep. op. xue)
ment of Somalia, with immediate effect, provided that a reciprocal
obligation was made by Somalia that it no longer has an objection to the
Commission on the Limits of the Continental Shelf examining the submissions
of The Republic of Yemen” (Note Verbale from the Permanent
Mission of the Republic of Yemen to the United Nations, dated 7 August
2019).
Apparently, Yemen has left the matter for delimitation.
45. Kenya initially objected to Somalia’s 2014 submission on the ground
that a significant part of Somalia’s continental shelf beyond 200 nautical
miles “is appurtenant to an EEZ that is under Kenya’s jurisdiction”. Subsequently,
in withdrawing its objection, Kenya states that,
“as longs [sic] as the Commission is aware of the area of overlapping
claims, and that, in respect of that area, it gives all due consideration to
the submissions made by both States, the Commission may proceed to
make recommendations concerning the outer limits of the continental
shelf off the coasts of Somalia and Kenya” (Note Verbale from the
Permanent Mission of the Republic of Kenya to the United Nations,
dated 30 June 2015).
Kenya’s statement to the CLCS apparently did not suggest that Somalia was
not entitled to the continental shelf but asserted that there was an overlap of
entitlements.
46. In the western Caribbean region, Colombia, Costa Rica, Jamaica and
Panama, individually or jointly, opposed Nicaragua’s submission on the
ground that Nicaragua’s claim encroached upon their respective maritime
areas. They rejected Nicaragua’s assertion that its submission is “without
prejudice to the delimitation of the continental shelf between Colombia,
Costa Rica and Panama” and reaffirmed their respective positions with
respect to Nicaragua’s submission (Communication from the Ministers
for Foreign Affairs of Colombia, Costa Rica and Panama, dated 5 February
2014, referring to the Note Verbale from the Permanent Mission of
Nicaragua to the United Nations, dated 20 December 2013). In denying
Nicaragua’s claim, these States objected to the Commission’s consideration
and ruling on Nicaragua’s submission. Colombia in its response dated
5 February 2014 referred to the existing maritime boundaries that it had
agreed with its neighbouring States, asserting that the submarine areas in
the Caribbean Sea that Nicaragua claimed in its submission belong to Colombia
under international law. As a non-party to UNCLOS, it dismissed
the opposability of Nicaragua’s submission to Colombia. In none of the
above communications did these States explicitly claim that, as a matter of
délimitation du plateau continental (op. ind. xue) 507
par le Gouvernement fédéral de Somalie au titre de l’article 76, avec effet
immédiat, sous réserve que la Somalie ait l’obligation réciproque de ne
plus faire objection à l’examen des demandes de la République du Yémen
par la Commission des limites du plateau continental » (note verbale en
date du 7 août 2019 adressée au Secrétaire général par la mission permanente
de la République du Yémen auprès de l’Organisation des Nations
Unies).
À l’évidence, le Yémen a jugé que c’était là une affaire de délimitation.
45. Le Kenya avait d’abord objecté à la demande présentée par la Somalie
en 2014, arguant qu’une partie importante du plateau continental somalien
au-delà de 200 milles marins correspondait en fait « à une zone économique
exclusive relevant de sa [propre] juridiction ». Il a par la suite levé son objection,
en que,
« dès lors qu’elle a connaissance de la zone de chevauchement des revendications
et examine avec toute la diligence voulue les demandes
soumises par les deux États concernant cette zone, la Commission [des
limites] peut formuler des recommandations sur la limite extérieure du
plateau continental au large des côtes de la Somalie et du Kenya » (note
verbale en date du 30 juin 2015 adressée au Secrétaire général par la
mission permanente de la République du Kenya auprès de l’Organisation
des Nations Unies).
Il est clair, dans cette déclaration, que le Kenya ne conteste pas que
la Somalie puisse revendiquer le plateau continental mais se borne à dire
qu’il y a chevauchement des espaces auxquels l’un et l’autre peuvent
prétendre.
46. Dans la région de la mer des Caraïbes occidentale, la Colombie, le
Costa Rica, la Jamaïque et le Panama, individuellement ou conjointement,
ont objecté à la demande du Nicaragua au motif que le plateau continental
revendiqué par ce dernier empiétait sur leurs espaces maritimes respectifs.
Ils ont démenti que la demande fût « sans préjudice de la délimitation du
plateau continental entre la Colombie, le Costa Rica et le Panama », comme
l’affirmait le Nicaragua, et ont réaffirmé leurs positions respectives
quant aux prétentions de ce dernier (lettre en date du 5 février 2014
adressée au Secrétaire général par les ministres des affaires étrangères
de la Colombie, du Costa Rica et du Panama, en référence à la note verbale
datée du 20 décembre 2013 de la mission permanente du Nicaragua auprès
de l’Organisation des Nations Unies). En contestant la revendication du
Nicaragua, ils s’opposaient à ce que la Commission des limites examine
la demande et se prononce à son sujet. Dans une réponse également datée
du 5 février 2014, la Colombie rappelait avoir déjà réglé la question des
frontières maritimes avec ses voisins, et affirmait que les zones sousmarines
revendiquées par le Nicaragua dans la mer des Caraïbes étaient
colombiennes au regard du droit international. N’étant pas partie à la
508 delimitation of the continental shelf (sep. op. xue)
principle, an extended continental shelf may not extend within 200 nautical
miles of another State. Colombia’s claim is primarily based on an argument
of established boundaries and the entitlement of its islands.
47. The above discussion shows that, even though many States parties in
their submissions to the CLCS have refrained from claiming a continental
shelf that extends within the 200-nautical-mile maritime zones of another
State, they have done so for various reasons; there is no consistent practice
among those States. The subsequent practice of many of them varies from
their position in the submissions, which seriously weakens the evidentiary
value of the submissions (Conclusion 7 of the ILC Conclusions). Moreover,
the other constitutive element for the identification of the alleged rule —
opinio juris — must be determined separately (ILC Conclusions, Conclusion
3, comment 7). There is no evidence shown in the Judgment that those
States parties, when restricting their claim in the submissions, believed that
such restraint was required by a legal obligation or guided by law. The practice
of States, particularly those States whose interests are directly or would
likely be affected by such practice, is neither widespread nor consistent.
More importantly, no single case can be found where a State has explicitly
given up its entitlement to an extended continental shelf on the ground that
it believes that its continental shelf may not extend within 200 nautical miles
of another State under international law. In any event, the 51 submissions,
which the Court considers as reflecting “the practice of the vast majority of
States parties”, in fact, do not truly reflect the positions of the States parties
on the issue in question. As discussed above, States such as Australia, Indonesia,
Papua New Guinea, France, the Maldives, and others, whose
submissions are included in the 51 submissions, clearly take a different view
on the entitlement to an extended continental shelf that encroaches on the
200-nautical-mile limit of another State.
48. Taking into account all the available practice of States and assessing it
as a whole, it can be said that there exists neither a general practice nor
opinio juris that denies the entitlement of a State to an extended continental
shelf that extends within 200 nautical miles from the coast of another State.
As many States affirm and have done, when such an overlap of entitlements
occurs, the matter shall be settled through the delimitation process in accordance
with the rule reflected in Article 83 of UNCLOS.
49. The potential impact of the present Judgment on the existing State
practice, the stability and security of treaties, the work of the CLCS and
délimitation du plateau continental (op. ind. xue) 508
CNUDM, elle considérait que la demande du Nicaragua devant la Commission
ne lui était pas opposable. Aucun des trois États n’a explicitement
dit, dans les communications susmentionnées, qu’un plateau continental
étendu ne pouvait pas, en principe, se prolonger en deçà de 200 milles
marins des côtes d’un autre État. La Colombie fait principalement valoir
l’existence de frontières établies et les espaces maritimes auxquels ont droit
ses îles.
47. Il ressort de ce qui précède que si de nombreux États parties à la
CNUDM, dans leurs demandes à la Commission des limites, se sont abstenus
de revendiquer un plateau continental s’étendant dans les zones maritimes
de 200 milles marins d’autres États, les raisons de cette retenue sont
cependant diverses ; il n’y a pas de pratique uniforme parmi ces États.
Nombre d’entre eux ont suivi par la suite une pratique qui s’écartait de la
position qu’ils avaient adoptée dans leurs demandes, ce qui réduit considérablement
la valeur probante de celles-ci (conclusion 7 des conclusions de la
CDI). De plus, l’autre élément constitutif de la détermination de la supposée
règle coutumière — l’opinio juris — doit être établi séparément (conclusion
3 des conclusions de la CDI, paragraphe 7 du commentaire). L’arrêt ne
donne aucune preuve de ce que les États parties en question, lorsqu’ils ont
limité leurs prétentions, considéraient que cette retenue était requise par une
obligation juridique ou guidée par le droit. La pratique suivie par les États,
en particulier ceux qui voient ou pourraient voir leurs intérêts menacés par
cette pratique, n’est ni répandue ni uniforme. Plus important encore, on ne
trouve pas un seul État qui aurait explicitement renoncé à revendiquer un
plateau continental étendu parce qu’il considérait que ce plateau ne pouvait
pas s’étendre jusqu’à moins de 200 milles marins des côtes d’un autre État
en vertu du droit international. En tout état de cause, les 51 demandes dont
la Cour estime qu’elles reflètent « la pratique de la grande majorité des États
parties » ne témoignent pas véritablement des positions desdits États sur la
question. Comme on l’a vu précédemment, des États comme l’Australie,
l’Indonésie, la Papouasie-Nouvelle-Guinée, la France, les Maldives et
d’autres, dont les demandes font partie des 51 exemples invoqués, ont manifestement
des avis différents sur le point de savoir si un État peut prétendre
à un plateau continental étendu empiétant sur la limite de 200 milles marins
d’un autre État.
48. Si l’on tient compte de toute la pratique étatique disponible et qu’on
l’évalue dans son ensemble, on peut dire qu’il n’existe ni une pratique
générale ni une opinio juris consistant à refuser à un État la possibilité de
revendiquer un plateau continental étendu se prolongeant en deçà de
200 milles marins des côtes d’un autre État. Ainsi que l’ont dit — et fait —
de nombreux États, un tel chevauchement de droits, lorsqu’il se produit,
doit être réglé par un processus de délimitation conformément à la règle
énoncée à l’article 83 de la CNUDM.
49. L’incidence que pourrait avoir le présent arrêt sur la pratique existante
des États, sur la stabilité et la sécurité des traités, ainsi que sur les travaux
509 delimitation of the continental shelf (sep. op. xue)
States’ submissions is unpredictable, particularly in respect of the existing
treaties and recommendations of the CLCS that have already accepted the
entitlement to an extended continental shelf that extends within 200 nautical
miles of another State. The CLCS may thus be placed at a crossroads as
to what to do with those “problematic” submissions.
III. Nicaragua’s Submissions on an Extended
Continental Shelf
50. Having considered the state of the law, I am of the view that Nicaragua
is entitled to an extended continental shelf, provided the existence and
outer limit of its continental margin is proven. As a precondition for delimitation,
Nicaragua has to first prove that its continental margin overlaps with
the entitlements of Colombia. For that purpose, the technical and scientific
evidence adduced by the Parties must first be examined.
51. Procedurally, the expert reports produced by the Parties were not further
examined at the oral proceedings because of the way in which the
hearing was organized. From the written pleadings, technical and scientific
evidence produced by Nicaragua seems to prove that its continental shelf,
the Nicaraguan Rise, extends far enough to reach within 200 nautical
miles from the mainland coast of Colombia. At the same time, however,
Colombia’s expert reports, in challenging the information contained in
Nicaragua’s submission to the CLCS with regard to the edge of the natural
prolongation of the Nicaraguan land territory in the Caribbean Sea, also
seem technically tenable. Without hearing from the Parties on those reports
and without the assistance of experts appointed by the Court, it is difficult to
assess the weight of each piece of evidence. This underscores the value and
indispensability of the recommendations from the CLCS. In hindsight I
believe that, in such a technically complicated case, it is a necessity for the
parties to obtain the recommendations of the CLCS before proceeding to
delimitation.
52. Notwithstanding my serious reservations regarding the reasoning of
the Court, there are two major considerations that led me to vote in favour of
the Court’s decision.
53. As a technical matter, the Parties are deeply divided over the scientific
and technical facts of Nicaragua’s extended continental shelf. Nicaragua
claims that the Nicaraguan landmass extends eastwards underwater to form
the dominant feature in the southwest Caribbean: the Nicaraguan Rise,
which is said to stretch over 500 nautical miles from the Nicaraguan landmass
in the southwest to Jamaica and Haiti in the north-east. The Nicaraguan
délimitation du plateau continental (op. ind. xue) 509
de la Commission des limites et les demandes dont les États la saisissent, est
imprévisible, en particulier en ce qui concerne les traités existants et les
recommandations par lesquelles la Commission a déjà accepté que le
plateau continental étendu revendiqué par un État se prolonge en deçà
de 200 milles marins des côtes d’un autre État. La Commission pourrait
ainsi se retrouver à la croisée des chemins s’agissant de la suite à donner à
ces demandes « problématiques ».
III. La demande de plateau continental étendu
du Nicaragua
50. Après avoir examiné l’état du droit, je suis d’avis que le Nicaragua peut
prétendre à un plateau continental étendu, pour autant que soit démontrée
l’existence de sa marge continentale et qu’en soit établie la limite extérieure.
Comme condition préalable à la délimitation, le Nicaragua doit commencer
par prouver que sa marge continentale chevauche les espaces auxquels a
droit la Colombie. Pour savoir si tel est le cas, il faut d’abord examiner les
preuves techniques et scientifiques produites par les Parties.
51. Sur le plan procédural, les rapports d’experts produits par les Parties
n’ont pas été examinés de manière approfondie pendant les audiences, en raison
de la manière dont celles-ci ont été organisées. Dans les écritures, les
preuves techniques et scientifiques du demandeur semblent démontrer que
son plateau continental — la ride (seuil) du Nicaragua — s’étend suffisamment
pour aller jusqu’à moins de 200 milles marins de la côte continentale
colombienne. En même temps, les rapports d’experts de la Colombie, qui
contestent les informations fournies par le Nicaragua, dans sa demande à la
Commission des limites, concernant le rebord du prolongement naturel de
son territoire dans la mer des Caraïbes, semblent également défendables du
point de vue technique. Faute d’avoir entendu les Parties à ce sujet, et sans le
concours d’experts désignés par la Cour, il est difficile d’évaluer le poids à
accorder à chaque élément de preuve. Cela met en évidence la valeur et la
nécessité des recommandations de la Commission. Avec le recul, je pense
que, dans une affaire aussi complexe du point de vue technique, il est indispensable
que les parties obtiennent les recommandations de la Commission
des limites avant de procéder à la délimitation.
52. Nonobstant mes sérieuses réserves au sujet du raisonnement de la
Cour, deux considérations majeures m’ont amenée à voter en faveur de sa
décision.
53. Sur le plan technique, les Parties sont profondément divisées au sujet
des faits scientifiques et techniques relatifs au plateau continental étendu du
Nicaragua. Ce dernier affirme que sa masse continentale se prolonge vers
l’est pour constituer la formation sous-marine dominante du sud-ouest des
Caraïbes : la ride du Nicaragua, qui s’étendrait sur plus de 500 milles marins,
de la masse continentale nicaraguayenne au sud-ouest jusqu’à la Jamaïque et
510 delimitation of the continental shelf (sep. op. xue)
Rise, as is shown, is separated from the oceanic abyssal plain of the Colombian
Basin to the south by a linear feature: the Hess Escarpment. Its northern
edge is formed by the Cayman Trough, a deep ocean trench lying to the
north of Honduras, running between Guatemala and the north coast of
Jamaica, approximately parallel to the Hess Escarpment. Nicaragua further
asserts that the Nicaraguan Rise is divided into two halves: to the north the
Nicaraguan Rise proper and — separated from it by the Pedro Bank Fracture
Zone — the Lower Nicaraguan Rise to the south. The Nicaraguan Rise is
about 150 nautical miles wide (i.e. north-south) and extends from the land
territory of Nicaragua in the west to Haiti in the east.
54. Contesting Nicaragua’s claim, Colombia’s expert reports present the
analyses of the scientific evidence collected from public sources and the
Colombian Navy on the natural prolongation of the seabed and subsoil from
the Nicaraguan land territory into and under the Caribbean Sea. The key
finding of the reports which is relevant to the present case is that the edge of
the natural prolongation of the Nicaraguan land territory in the Caribbean
Sea is not the Hess Escarpment (the southern limit of the Nicaraguan Rise as
assumed by the Applicant), but the Pedro Bank Escarpment-Providencia
Trough Lineament, which separates the southern edge of the Nicaraguan
Rise proper from the Lower Nicaraguan Rise. According to Colombia’s
experts, the scope of Nicaragua’s continental margin is much smaller than
Nicaragua’s experts suggest and, consequently, Nicaragua’s landmass does
not extend within 200 nautical miles from the mainland coast of Colombia.
55. The technical characterization of Nicaragua’s continental margin must
be left to scientific and technical experts. Divergent as they are, the expert
reports of the Parties, at the least, inform the Court of some basic facts that
are crucial for the consideration of Nicaragua’s submissions to the Court for
adjudication in the present case.
56. First, the relationship between Nicaragua’s continental margin and
Colombia’s mainland coast remains highly uncertain. Even relying on Nicaragua’s
evidence, the outer limit of the Lower Nicaraguan Rise in the northeast,
as defined by Nicaragua, seems overexpansive. The materials submitted
by Nicaragua are not sufficient for the Court to ascertain whether and to
what extent Nicaragua’s continental shelf extends within 200 nautical miles
of Colombia.
57. Additionally, the Court has never dealt with such a case where the
delimitation involves the extended continental shelf of only one party. Even
assuming that the Nicaraguan Rise is southbound by the Hess Escarpment,
as asserted by Nicaragua, and that Nicaragua’s entitlement is established and
overlaps with Colombia’s entitlements within 200 nautical miles from its
mainland coast, the question nevertheless remains as to what methodology
the Court should adopt to delimit the boundary between the Parties in the
area. It seems highly problematic to apply the three-stage delimitation methdélimitation
du plateau continental (op. ind. xue) 510
Haïti au nord-est. La ride du Nicaragua est séparée de la plaine abyssale
océanique du bassin colombien, au sud, par une formation linéaire : l’escarpement
de Hess. Au nord, son bord est formé par la fosse des Caïmans, une
fosse océanique profonde située au nord du Honduras, qui s’étend entre le
Guatemala et la côte septentrionale de la Jamaïque, plus ou moins parallèlement
à l’escarpement de Hess. Selon le Nicaragua, la ride est divisée en
deux : au nord, la ride proprement dite, et au sud, séparée par la zone de fracture
du banc de Pedro, la ride inférieure. La ride du Nicaragua a une largeur
(c’est-à-dire du nord au sud) d’environ 150 milles marins et s’étend du territoire
terrestre du Nicaragua, à l’ouest, jusqu’à Haïti, à l’est.
54. Les experts de la Colombie contestent la revendication du Nicaragua en
analysant des preuves scientifiques, provenant de sources publiques et de la
marine colombienne, sur le prolongement naturel des fonds marins et de
leurs sous-sols du territoire terrestre nicaraguayen dans, et sous, la mer des
Caraïbes. La principale conclusion de ces rapports qui est pertinente en l’espèce
est que le bord du prolongement naturel du territoire terrestre
nicaraguayen dans la mer des Caraïbes est non pas l’escarpement de Hess (la
limite méridionale de la ride du Nicaragua, selon le demandeur), mais le
linéament formé par l’escarpement du banc de Pedro et la fosse de Providencia,
qui sépare le bord méridional de la ride proprement dite de la ride
inférieure. Selon les experts de la Colombie, l’étendue de la marge continentale
nicaraguayenne est bien moindre que ne le disent les experts du
demandeur et, par conséquent, la masse continentale du Nicaragua ne s’étend
pas jusqu’à moins de 200 milles marins de la côte continentale colombienne.
55. La qualification technique de la marge continentale du Nicaragua doit
être laissée aux experts scientifiques et techniques. Pour divergents qu’ils
soient, les rapports d’experts des Parties informent à tout le moins la Cour de
certains faits fondamentaux qui sont essentiels pour examiner les questions
que le Nicaragua lui a demandé de trancher en l’espèce.
56. Premièrement, la relation entre la marge continentale nicaraguayenne
et la côte continentale colombienne demeure très incertaine. Même si l’on
accorde foi aux éléments de preuve qu’a produits le demandeur, la limite
extérieure de la ride inférieure, au nord-est, telle qu’il l’a lui-même définie,
semble exagérément étendue. Les données fournies ne sont pas suffisantes
pour permettre à la Cour de déterminer si, et sur quelle distance, le plateau
continental du Nicaragua s’étend en deçà de 200 milles marins des côtes de
la Colombie.
57. En outre, la Cour n’a jamais eu à connaître d’une affaire de délimitation
concernant le plateau continental étendu d’une seule partie. Même à supposer
que la ride du Nicaragua soit bordée au sud par l’escarpement de Hess,
comme l’affirme le demandeur, et qu’il soit établi que ce dernier peut prétendre
à un espace maritime chevauchant ceux auxquels la Colombie a droit
sur une distance de 200 milles marins à partir de sa côte continentale, la
question se pose néanmoins de savoir quelle méthode la Cour devrait adopter
pour délimiter la frontière entre les Parties dans la zone en question. Il
511 delimitation of the continental shelf (sep. op. xue)
odology that is usually used for maritime delimitation within 200 nautical
miles; the relevant considerations for achieving an equitable solution may be
quite different in the present situation.
58. Moreover, the Court should not lose sight of the overall geographical
context in which Nicaragua’s purported continental shelf is located. As is
shown on the maps presented by the Parties, situated on the Nicaraguan
Rise, alongside Nicaragua, are Colombia’s Archipelago of San Andrés,
Providencia and Santa Catalina, Jamaica and Haiti. In the western Caribbean,
there is Jamaica to the north and Panama to the south. Notwithstanding
the existing delimitation treaties between each of these States and Colombia,
which are not opposable to Nicaragua, res inter alios acta, the
entitlements of those States to a continental shelf within 200 nautical miles
would likely overlap with any extended continental shelf Nicaragua may
have. Therefore, it is doubtful that any extended continental shelf that
Nicaragua might have established could be given its full effect to the extent
that Nicaragua claims. As between the Parties, it is Colombia’s islands
that are situated in the middle of the mainland coasts of the two States that
prove crucial for the delimitation between the Parties.
59. In the 2012 Judgment, the Court clearly did not delimit the maritime
area eastward beyond the relevant area as identified for the delimitation of
the maritime boundary between the Parties within 200 nautical miles from
the mainland coast of Nicaragua (Territorial and Maritime Dispute (Nicaragua
v. Colombia), Judgment, I.C.J. Reports 2012 (II), p. 683, para. 159). In
rejecting Nicaragua’s proposal to draw a series of enclaves around each of
Colombia’s islands, the Court underscored the requirement not to produce
cut-off effect in the delimitation. It considered, in particular, that
“[e]ven if each island were to be given an enclave of 12 nautical miles,
and not 3 nautical miles as suggested by Nicaragua, the effect would be
to cut off Colombia from the substantial areas to the east of the principal
islands, where those islands generate an entitlement to a continental
shelf and exclusive economic zone. In addition, the Nicaraguan proposal
would produce a disorderly pattern of several distinct Colombian
enclaves within a maritime space which otherwise pertained to Nicaragua
with unfortunate consequences for the orderly management of
maritime resources, policing and the public order of the oceans in general,
all of which would be better served by a simpler and more coherent
division of the relevant area.” (Ibid., p. 708, para. 230.)
The Court, by implication, recognized that Colombia’s islands are entitled to
their continental shelves under customary international law. In the present
case, should Nicaragua’s second and third submissions — similar to the
délimitation du plateau continental (op. ind. xue) 511
semble très problématique d’appliquer la méthode en trois étapes habituellement
utilisée pour une délimitation maritime dans la limite des 200 milles
marins ; dans la situation de l’espèce, les considérations pertinentes qui permettent
de parvenir à une solution équitable pourraient être tout à fait
différentes.
58. La Cour ne doit pas non plus perdre de vue le contexte géographique
global dans lequel se situe le plateau continental supposé du Nicaragua.
Comme le montrent les cartes présentées par les Parties, sur la ride du Nicaragua
se trouvent, outre le territoire nicaraguayen, l’archipel colombien de
San Andrés, Providencia et Santa Catalina, ainsi que la Jamaïque et Haïti.
Dans les Caraïbes occidentales, il y a la Jamaïque au nord et le Panama au
sud. Nonobstant les traités de délimitation conclus par chacun de ces pays
avec la Colombie, qui ne sont pas opposables au Nicaragua, res inter alios
acta, tout plateau continental auquel ces États ont droit dans la limite de
200 milles marins chevaucherait probablement tout plateau continental
étendu du Nicaragua. Par conséquent, il est douteux qu’un tel plateau, même
si son existence était établie, puisse se voir accorder plein effet dans toute la
mesure où le voudrait le Nicaragua. Pour ce qui est de la délimitation entre
les Parties, ce sont les îles colombiennes situées entre leurs côtes continentales
respectives qui sont cruciales.
59. Dans son arrêt de 2012, la Cour n’avait pas, à l’évidence, délimité l’espace
maritime qui s’étend vers l’est au-delà de la zone déterminée comme
pertinente aux fins de la délimitation de la frontière maritime entre les
Parties en deçà de 200 milles marins de la côte continentale nicaraguayenne
(Différend territorial et maritime (Nicaragua c. Colombie), arrêt, C.I.J.
Recueil 2012 (II), p. 683, par. 159). En refusant de tracer une série d’enclaves
autour de chacune des îles colombiennes, comme le proposait le Nicaragua,
la Cour a mis en évidence la nécessité de ne pas créer un effet d’amputation
dans la délimitation. Elle a jugé, notamment, que,
« [m]ême si chaque île devait se voir attribuer une enclave de 12 milles
marins, au lieu de 3 comme le propose le Nicaragua, cette solution aurait
pour effet d’amputer la Colombie de vastes zones situées à l’est de ses îles
principales, où celles-ci lui donnent droit à un plateau continental et à
une zone économique exclusive. En outre, la proposition nicaraguayenne
donnerait naissance à un système désorganisé d’enclaves colombiennes,
coupées les unes des autres, à l’intérieur d’un espace maritime qui ressortirait
par ailleurs au Nicaragua. Ce système aurait des conséquences
fâcheuses sur les activités de surveillance ainsi que sur la gestion ordonnée
des ressources maritimes et des océans en général, autant de fins
qu’un partage plus simple et plus cohérent de la zone pertinente permettrait
d’atteindre plus aisément. » (Ibid., p. 708, par. 230.)
La Cour reconnaissait ainsi implicitement que les îles colombiennes ont
droit à leur plateau continental en vertu du droit international coutumier.
En la présente espèce, si les deuxième et troisième demandes du Nicaragua
512 delimitation of the continental shelf (sep. op. xue)
request Nicaragua had made in the Territorial and Maritime Dispute case —
be upheld, it would produce a cut-off effect between the islands and the
mainland of Colombia. Indeed, it would not be conducive to an orderly management
of the maritime area and a coherent relationship among the coastal
States in the western Caribbean. As Colombia’s islands in the east face the
mainland coast of Colombia, their entitlements to an exclusive economic
zone and continental shelf should be given full effect. Furthermore, they are
situated on the landmass constituting part of the continental shelf claimed by
Nicaragua. Under the circumstances, it is questionable whether Nicaragua
could still make a good case for its claim.
60. Based on the foregoing considerations, I come to the conclusion that
Nicaragua’s submissions should not be upheld.
(Signed) Xue Hanqin.
délimitation du plateau continental (op. ind. xue) 512
— similaires à celle qu’il avait formulée en l’affaire du Différend territorial
et maritime — avaient été accueillies, il en serait résulté un effet d’amputation
entre les îles et le territoire continental de la Colombie. Assurément, un
tel résultat ne favoriserait pas une gestion ordonnée de la zone maritime ni
une relation harmonieuse entre les États côtiers des Caraïbes occidentales.
Étant donné qu’elles font face à la côte continentale colombienne, les îles
de la Colombie situées à l’est devraient se voir reconnaître avec plein effet
leurs droits à une zone économique exclusive et à un plateau continental. En
outre, elles se trouvent sur la masse continentale qui constitue une partie du
plateau continental revendiqué par le Nicaragua. Dans ces conditions, on
peut se demander si le Nicaragua pourrait encore justifier sa revendication.
60. Compte tenu de ce qui précède, j’en viens à la conclusion qu’il convenait
bien de rejeter les demandes du Nicaragua.
(Signé) Xue Hanqin.

Document file FR
Document Long Title

Separate opinion of Judge Xue

Order
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