Rcqucst by the United Nations Gcncral Asscmbly for an Advisory Opinion on the
"Lcgal conscqucnccs of the scparation of the Chagos Archipelago from Mauritius in 1965"
Written comments of the United States of America on the Written Reply of Mauritius
of September 7, 2018 to the question posed by Judge Gaja
1. The United States offers three observations on the Written Reply of Mauritius to the
following question posed by J udge Gaja on September 3: "In the process of decolonization
relating to the Chagos Archipel a go, what is the relevance of the will of the population of
Chagossian origin?"
2. First, the United States remains of the view that the Court should exercise its discretion to
decline to respond to the questions referred by the General Assembly. To respond to those
questions would require the Court to examine a number of issues that bear directly on the
main points of the dispute between Mauritius and the United Kingdom, including the role of
consent of the elected representatives of Mauritius. These would not be appropriate inquiries
in an advisory proceeding.
3. Second, as discussed in detail in our written and oral submissions, by the Court's own
standards for determining the existence of a rule of customary international law, no rule had
crystallized by 1965 or 1968 that would have prohibited the establishment of the British
Indian Ocean Territory. 1
4. Third, in its response to Judge Gaja's question, Mauritius continues to make questionable or
erroneous assertions. As we noted in our Written Comments, for example, it should not
simply be taken as fact that the present-day people of Mauritius represent the wishes of all
Chagossians throughout the world. In this respect, the United States directs the Court's
attention to paragraph 4.4 of the United States Written Comments of May 15, 2018, in which
we addressed this assumption, which appeared in several written statements from the first
round of submissions:
1 See United States Written Statement, Chapter IV; United States Written Comments, Chapter Ill; United States Oral
Presentation, paras. 35-66.
[S]cvcral statements assumed that any unexerciscd right of self-determination with
respect to the Chagos Archipelago would belong to the present-day people of
Mauritius. 151 If, however, the Court were to determine that any right of self-determination
exists in these circumstances and remains to be exercised, the holder of that right may not
be the modern people of Mauritius. 152 As the Republic of Seychelles highlighted in its
submission, a significant Chagossian population is present in the Seychelles. 153
Chagossians are also living in the United Kingdom. 154 As such, determining who may
hold the right of self-determination with respect to the Chagos Archipelago today would
be an exceedingly complicated undertaking.
5. In the view of the United States, such an undertaking is not appropriate in the context of an
advisory opinion given its direct relationship to issues at the heart of a bilateral sovereignty
dispute. If it were undertaken, it is difficult to see how the Court could resolve the question
in the absence of detailed submissions by States on this specific issue during the earlier
stages of these proceedings.
151 See, e.g., African Union Written Statement, paras. 66,224; Argentina Written Statement, para. 51; Belize Written
Statement, para. 4.2; Djibouti Written Statement, para. 42; Mauritius Written Statement, para. 6.3(5); Namibia
Written Statement, pp. 3-4; Serbia Written Statement, para. 50; South Africa Written Statement, para. 85.
151 See, e.g., STEPHEN ALLEN, THE CHAGOS ISLANDERS AND INTERNATIONAL LAW 286 (2004) ("The Chagos
Islanders ... qualify as the beneficiaries of the entitlement to self-determination in relation to the BIOT.").
153 Seychelles Written Statement, paras. 4, 6 (noting that "a significant number of the Chagossians were brought to
the Seychelles" and requesting "that the unique perspectives and legitimate concerns of the Seychellois Chagossian
community be taken into due consideration").
154 United Kingdom Written Statement, para.1.5 n. 7; id., para. 4.38.
Written Comments of the United States of America on the Written reply of Mauritius to the question put by Judge Gaja at the end of the hearing held on 3 September 2018