Abstract: Did the UK act illegally in splitting off the Chagos Islands from Mauritius prior to its independence in 1968? On 22 June 2017 Mauritius successfully petitioned the UN to ask the International Court of Justice to consider this question, against the UK’s wishes, but the outcome is rather uncertain. This contribution explains why.
In 1965, the UK excised the Chagos Islands from the British colony of Mauritius to create the British Indian Ocean Territory (BIOT) after reaching an agreement with the representatives of the Mauritian colonial government (known as the 1965 Lancaster House Agreement). The UK paid Mauritius £3 million in recognition of the detachment of the Chagos Islands and gave undertakings to cede the islands to Mauritius when ‘no longer needed for our defence purposes’ as well as other benefits including fishing and mineral rights.
Readers might be familiar with the wide range of disputes that have arisen as a result of the detachment of the Chagos Islands form the colony of Mauritius, ranging from the exile of the entire population of the inhabitants of the Chagos Islands (known as the Chagossians) to make way for what is now a fully-fledged US military base on the remote Island of Diego Garcia, to the protection afforded to the Chagossians by human rights law, the designation of maritime protection areas around the BIOT, and the core sovereignty dispute between Britain and Mauritius over the Islands.
On 22 June 2017, Mauritius successfully petitioned the United Nations (UN) to ask the International Court of Justice (ICJ) to consider these questions, against the UK’s wishes. By 94 to 15 with 65 States abstaining, the UN General Assembly requested the ICJ to provide an advisory opinion on the legality of the separation by the United Kingdom of the Chagos Islands from the colony of Mauritius prior to the grant of independence to Mauritius by the UK in 1968. The ICJ fixed 30 January 2017 as the time-limit for the submission of written statements by the UN and its Member States and also by the African Union. The deadline has been extended to 1 March 2018. It is probably fairly easy to guess what the Mauritian and UK government submissions will contain. But there are more players involved than just those two countries. Most importantly there are the Chagossians themselves, who were forcibly exiled from the archipelago to make way for what is now a fully-fledged US military base on the island of Diego Garcia.
The operative part of the Resolution (the request that the Court is asked to address) reads as follows:
(a) “Was the process of decolonization of Mauritius lawfully completed when Mauritius was granted independence in 1968, following the separation of the Chagos Archipelago from Mauritius and having regard to international law, including obligations reflected in General Assembly resolutions 1514 (XV) of 14 December 1960, 2066 (XX) of 16 December 1965, 2232 (XXI) of 20 December 1966 and 2357 (XXII) of 19 December 1967?”;
(b) “What are the consequences under international law, including obligations reflected in the above-mentioned resolutions, arising from the continued administration by the United Kingdom of Great Britain and Northern Ireland of the Chagos Archipelago, including with respect to the inability of Mauritius to implement a programme for the resettlement on the Chagos Archipelago of its nationals, in particular those of Chagossian origin?”.
The drafting of the question posed to the Court is remarkable in many respects. First, it is fairly broad thus, allowing the Court to exercise its competence with some flexibility as to the interpretation of the question itself and as to the content of its opinion. At the same time, it is sufficiently specific and, thus, being susceptible of a certain response based on law. Second, the question does not directly ask the Court to ascertain whether Mauritius has sovereignty over the Chagos Islands but whether the decolonization of Mauritius had been carried out in a lawful manner, given the Islands’ subsequent separation from Mauritius’ territory.
The request also makes links to numerous UN General Assembly resolutions (relating to decolonization and the principle of self-determination) in order to make clear that this is a multifaceted dispute, raising much broader questions than just the sovereignty dispute over the Chagos Islands. The question is also notable in that it does not simply ask what are the legal consequences would be if the Court found that the UK acted wrongfully in detaching the Chagos Islands from Mauritius. Rather, the consequences are those ‘arising from the continued administration by the United Kingdom… including with respect to the inability of Mauritius to implement a programme for the resettlement on the Chagos Archipelago’. This would allow the Court to deal with a number of issues that do not directly relate to the question of sovereignty or faults in the decolonization process, such as notably the Chagossians claims of a right to return to the Chagos Islands and the reparation for their involuntary displacement.
It is generally understood that when the Court is seized with a request to give an advisory opinion ‘on any legal question’ the Court must first consider whether it has jurisdiction to give the opinion requested and, should the answer is in the affirmative, whether it is appropriate for it to exercise that jurisdiction. Assuming that the Court decides to exercise its propriety to give an advisory opinion on this case, one of the primary legal issues it will probably have to examine is whether the Chagos Islands formed an integral part of Mauritius before 1965. The UK has argued that the Chagos Islands were only administered by Mauritius, ‘as a matter of convenience’, and were not really a part of Mauritius’ territory (see Counter-Memorial by the United Kingdom, 2013). If that is sustained, then the Court is more likely to conclude that the process of decolonization of Mauritius was lawfully completed. If, on the contrary, the Chagos Islands were an integral part of Mauritius prior to its independence, the legality, or illegality, of their detachment would have to be grounded in a number of subsequent issues, including the questions as to when and how, did the right of colonial self-determination acquired its binding character as a matter of general international law and vis-à-vis the UK in particular.
Many of these questions are depended on inter-temporal considerations in the sense that the legality of the UK’s actions are to be judged by the law in force at the time the actions occurred. For example, the ICJ would have to ascertain whether the right to self-determination in the Mauritian context had achieved the status of binding international law vis-a-vis the UK by the time the Chagos Islands were excised from Mauritius pursuant to the terms of the 1965 BIOT Order in Council and the 1965 Lancaster House Agreement. If the right of colonial self-determination became binding upon the UK after the Chagos Islands were detached from Mauritius, then, as a matter of principle, it would be difficult to establish that the UK’s conduct was in breach of the right to self-determination in the Mauritian context. If, on the other hand, the right of colonial self-determination had acquired the status of binding international law by 1965, the dismemberment of Mauritius before it had acceded to independence would amount to a violation of this right.
Nevertheless, the detachment could still be considered lawful if the Court finds that those who accepted the UK’s proposal for the excision of the Chagos Islands from Mauritius were a) the legitimate representatives of the Mauritian government and; b) they acted voluntarily. Mauritius has argued that the agreement between the UK and the former representatives of Mauritius to the excision of the Chagos Islands ‘does not validate the dismemberment of Mauritius’ because it was ‘obtained under conditions of duress and coercion’ (see Memorial of Mauritius, 2012).
Finally, given the broad drafting of the question posed, the Court has the opportunity to go beyond the matter of the legality of the detachment of the Chagos Islands. Indeed, it is theoretically possible that the UK’s administration of the Chagos Islands might have breached some international law norms even if the Court concludes that the detachment itself was lawful. The Court could conclude, for instance, that the UK has breached some of the terms of 1965 Lancaster House Agreement. In 2016, the UK extended the lease of the US military base on Diego Garcia for a further 20 years despite the vigorous opposition of the Mauritius government which saw the renewal likely as significant for the condition in which the Islands will eventually return to Mauritius as the controversial marine protected area around the BIOT which a Law of the Sea tribunal later rendered unlawful.
It could also conclude that the UK breached some of its obligations towards the former inhabitants of the Islands. It is true that the UK government has historically taken some exceptional measures to prevent the return of the Chagossian community to their Indian Ocean homes; a sign perhaps of its own uncertainty over the legality of its actions. In 2000, it withdrew the Chagossian right of abode in the BIOT, and, in 2004, it reinstated full immigration restrictions over the BIOT. After all, it was against the background of the UN-inspired decolonisation process in the 1960s, that the US and UK governments covertly agreed that the entire population of the Chagos Islands would be removed before the US government took possession of Diego Garcia (Chagos Islanders v Attorney General & HM BIOT Commissioner  EWHC QB 2222, Appendix A: Events leading up to the creation of BIOT).
Despite knowing that the Chagos Islands supported an indigenous population which was ethnically and culturally distinct, the UK government chose not to disclose this information to the UN General Assembly, possibly for fear that the BIOT would be classified as a non-self-governing territory. Under Chapter XI of the UN Charter, States which administer ‘territories whose peoples have not yet attained a measure of self-government’ have to ensure and promote the interests and the well-being of the inhabitants of these territories and to transmit relevant reports to the UN Secretary-General. If the BIOT were deemed a non-self-governing territory, it would mean the Chagos Islanders had the right to choose their own political future and achieve self-government. It would also mean that the UK, as the administering State, did not have the right to divide up or dismember the BIOT in violation of self-determination, as leading expert, Dr Stephen Allen, argues. Or, indeed, forcibly remove the inhabitants and prevent their return. Not the outcome that Mauritius or the UK – or the USA – are hoping for, but one that would be welcomed by those Chagossians who have been campaigning for the right to return for over 40 years.
***The views expressed herein do not necessarily represent the opinions of JTMS or Yonsei Institute for North Korean Studies
Author Bio: Dr Constantinos Yiallourides is the Arthur Watts Research Fellow on the International Law of Territorial Disputes at the British Institute of International and Comparative Law (BIICL). His research expertise spans a number of international law fields with a particular focus on the law of the sea, the law of territory, environmental/natural resources law and the peaceful settlement of international disputes. He has published widely on these areas and has assisted governments, international organisations, and other entities on matters of international law. Constantinos is also a Teaching Associate at the University of Aberdeen where he teaches law of the sea, oil and gas law, theory of regulation and critical legal skills. He is a member of the International Union for Conservation of Nature (IUCN), the World Commission on Environmental Law (WCEL), the European Society of International Law (ESIL), and an Associate Fellow of the Higher Education Academy (UK).