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The UN Maritime Court Rules That Britain Does Not Have Sovereignty Over Chagos Islands

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The Chagos Islands or the Chagos Archipelago comprises of 60 tropical islands in the Indian Ocean roughly 500 kilometres south of the Maldives. The Islands are home to the Chagossians, who had lived there for more than two centuries. They were evicted by the UK between 1967 to 1973 to house a military base for the United States in the largest island of the Chagos, the Diego Garcia. 

Since at least 1971, the sovereignty of the Chagos Archipelago has been a dispute between the UK and Mauritius. Prior to the independence of Mauritius in 1965, the UK formed the British Indian Ocean Territory (BIOT) comprising of the Chagos Islands, the islands of Aldabra, Farquhar, and Desroches from Seychelles. The BIOT was established to form an oversea territory for the UK. Later in 1976, the Aldabra, Farquhar, and Desroches islands were returned to Seychelles. However, the UK continued to illegally occupy the Chagos territory. Subsequently, in 2017, the UN General Assembly (UNGA) asked the International Court of Justice (ICJ) to give an advisory opinion on the separation of the Chagos Archipelago from Mauritius. In February 2019, the ICJ ruled that the UK must discontinue occupation of the islands as “soon as possible”. In May 2019, the General Assembly, in a 116 state vote (majority) adopted a resolution affirming that the Chagos Islands belonged to Mauritius. 

The International Tribunal for the Law of the Sea (ITLS)

In a press release dated on the 28th of January 2021, the ITLS criticized the UK government’s failure to hand over the Chagos territory to Mauritius despite longstanding promises on its part and despite the ruling from the ICJ and a resolution the UNGA. The Special Chamber of the ITLS was adjudicating the dispute concerning delimitation of the maritime boundary between Mauritius and Maldives in the Indian Ocean. The proceedings had been instituted by the Maldives in December 2019, and publicly heard between the 13th and 19th of October 2020 in hybrid formats. The centre of these hearings where five Preliminary Objections raised by the Maldives. This included: (1) indispensable third party (UK), (2) disputed issue of sovereignty, (3) the requirement under articles 74 and 83 of the United Nations Convention on the Law of the Sea (“the Convention”), (4) existence of a dispute, and (5) abuse of process. Furthermore, Maldives also objected to the jurisdiction and admissibility of the ITLS. 

Regarding the first-two Preliminary Objections, the Maldives argued that the UK was an indispensable third party to the current dispute. Since they had not been involved in these proceedings, the Special Chamber does not have jurisdiction over the dispute in question. Moreover, Maldives also contends that the Special Chamber does not have jurisdiction to determine whether the disputed issue of sovereignty over the Chagos Archipelago, which the Special Chamber would necessarily need to have to determine Mauritius’ claim over the current dispute. Mauritius, alternatively, argued that the UK was not an indispensable party of the dispute, and in addition, considering the ICJ advisory opinion, the legal status of the Chagos Archipelago was clear and not disputed. The Special Chamber held that the UK did not have sufficient legal interested in the Chagos Islands to be considered as an “indispensable third party” that would be affected by the delimitation of the maritime boundary between the Maldives and Mauritius. Moreover, in light of the Chagos advisory opinion, and the UNGA resolution, the Chagos Islands belonged to Mauritius.  

Regarding the third Preliminary Objection, the Maldives had argued that since Mauritius and the Maldives had failed to engage and could not meaningfully engage in the negotiations required by articles 74 and 83 of the Convention, the Special Chamber lacked jurisdiction. Alternatively, Mauritius argued that articles 74 and 83 of the Convention did not impose any obligation to negotiate as a jurisdiction precondition to invoke proceedings as provided for in Part XV of the Convention and that the parties did in fact engage in negotiations in regard to the disputed maritime boundary. The Special Chamber concluded that “in situations in which ‘no agreement [could] be reached’, to resort the procedures of Part XV of the Convention, as set out in para 2 of articles 74 and 83, is not only justified but also an obligation of the States concerned, thus, rejecting the third Preliminary Objection.

As for the fourth Preliminary Objection, the Maldives argued that there was no, and could not be any dispute between itself and Mauritius concerning their maritime boundary, and thus, without such a dispute, the ITLS did not have jurisdiction to hear the case. On the contrary, Mauritius argued that the Special Chamber did in fact have jurisdiction as the dispute existed between the parties even as late as 2010. The Special Chamber concluded that “a dispute existed between the parties concerning the delimitation of their maritime boundary” at the time of the filing of the Notification; thus, rejecting Maldives argument. 

Finally, the fifth Preliminary Objection that the Maldives raised was that Mauritius’ claims constituted an abuse of power and thus were inadmissible. In the Maldives’ view, Mauritius was using the compulsory dispute settlement procedures of the Convention to obtain a ruling on a territorial dispute with a third State. Mauritius, alternatively, argued that the Maldives objection is unsubstantiated and that it did not seek a ruling on the sovereignty over the Chagos Islands. The Special Chamber concluded that under articles 74 and 83 requirements, a dispute between the parties concerning the delimitation of their maritime boundary existed at the time of filing the Notification. Moreover, Mauritius resorted to dispute settlement in accordance with the provisions of the Convention; thus, Mauritius’ claims were not an abuse of process. As an overall conclusion, in an 8:1 judgment, the Special Chamber of the ITLS held that it did have the jurisdiction to adjudicate the case and that Mauritius’ claims were admissible; effectively, concluding that the Chagos Islands belonged to Mauritius. 

A copy of the Press Release of the Special Chamber can be found here. is now on Telegram. Follow us for regular legal updates and judgment from courts. Follow us on Google News, InstagramLinkedInFacebook & Twitter. You can subscribe to our Weekly Email Updates. You can also contribute stories like this and help us spread awareness for a better society. Submit Your Post Now.

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