Written evidence submitted by Professor Philippe Sands (CHA0023)

1. I am pleased to be able to make a submission to the Foreign Affairs Sub-Committee on the Overseas Territories for the inquiry on ‘The UK Government’s engagement regarding the British Indian Ocean Territory’.[1]

2. At the outset, I wish to make clear that as a member of the Bar of England and Wales I have acted as counsel to Mauritius since 2010 in relation to the Chagos Archipelago. As such, I have been involved in the proceedings before the Annex VII arbitral tribunal (2010-2015), the International Court of Justice (ICJ, 2017-2019) and the International Tribunal for the Law of the Sea (ITLOS, 2019-2023). I continue to advise the Government of Mauritius. I make this submission in a personal capacity, as an academic and a writer, drawing in part from my professional involvement. The views I express should not be taken to express the views of any Government or third party.

3. By way of background, I have made available to members of the Sub-Committee a copy of my book The Last Colony (Weidenfeld & Nicolson, 2022). The book is translated into several languages, including French, Italian, Spanish, German, Dutch and Polish, and more translations are in preparation. This attests to the interest in the subject. I attach as an annex a copy of an opinion piece I published in the New York Times in April 2021. It set out my personal views, and obtained significant and positive responses from within the Biden Administration.

4. The background to the Inquiry is fully set out in The Last Colony. The ICJ, ITLOS, the United Nations and its specialised agencies all recognise that the entirety of the Chagos Archipelago, including Diego Garcia, is (and has always been) an integral part of the sovereign territory of Mauritius. The territory of the “British Indian Ocean Territory” was illegally detached from Mauritius in 1965, and the forcible deportation of the entire population between 1968 and 1973 was illegal. That deportation, and its continuing effects, is widely seen as a crime against humanity. In short, “BIOT” is an illegal construct under international law. By its resolution 73/295, adopted by an overwhelming majority on 22 May 2019, the UN General Assembly (UNGA) called on the United Kingdom to end it illegal occupation of the Chagos Archipelago by the end of 2019. It also called on the United Nations and all its specialised agencies, and all other international organisations, “to refrain from … recognizing, or giving effect to any measure taken by or on behalf of, the “British Indian Ocean Territory”.[2]

5. Two years later, in 2021, a Special Chamber of ITLOS handed down a binding judgment, in a maritime boundary dispute between Mauritius and the Maldives. The Special Chamber ruled that the 2019 ICJ Advisory Opinion is an authoritative statement of international law and that Mauritius has sovereignty over the whole of the Chagos Archipelago, including Diego Garcia. The judgment of the Special Chamber of ITLOS is binding and final. It ruled that the UK claim to sovereignty over the Chagos Archipelago was no more than a “mere assertion”; that it was “contrary to the determinations made by the ICJ” , which “have legal effect”; and that it was “inconceivable” that the United Kingdom “can have any legal interests in … maritime zones around the Chagos Archipelago”.[3] Following this ruling, in 2023 the Special Chamber delivered a further judgment that delimited the maritime boundary between Mauritius (the Chagos Archipelago) and Maldives (Addu Atoll). This delimitation is now recognised around the world.

6. The Sub-Committee needs to be aware that since 2015 no less than 28 distinguished international judges and arbitrators have had an opportunity to express views on sovereignty over the Chagos Archipelago. Not a single one of these judges has expressed any support for a United Kingdom claim to sovereignty. The UK claim to sovereignty is unarguable and, frankly, embarrassing. I am not aware of any serious public international lawyer who has, in the face of recent developments, expressed support for a UK claim. To the best of my knowledge, the legal advisers at the FCDO and the Ministry of Defence have not sought to justify that claim by reference to the rules of international law, since the ICJ, ITLOS and UNGA determinations.

7. As the “British Indian Ocean Territory” is illegal under international law, Britain is currently in illegal occupation of a part of the territory of Mauritius, and of the continent of Africa. It follows too – regrettably - that the operation of the military base at Diego Garcia is not in conformity with international law. So long as the UK’s illegal occupation continues, Britain’s position is no different from that of South Africa in relation to Namibia (from 1971 to 1994), Russia in relation to Crimea and other parts of the territory of Ukraine (since 2014), or China in relation to certain claims in relation to the South China Sea.

8. The only way to bring matters into conformity with international law, with regard to the base at Diego Garcia, is for the UK to enter into an agreement with Mauritius. That was wisely understood by the UK Government in September 2022, when it decided to negotiate a solution with Mauritius on the basis of international law. It did so in part because of the grave harm being done to Britain’s international reputation. This welcome new direction set the UK on the path of a return to legality. As has been publicly reported, negotiations began in November 2022, and I believe significant progress was made until November 2023. My understanding is that an agreement is within sight, and could be reached within weeks. That agreement would be a major and positive achievement: it would secure the recognition of Mauritian sovereignty over the Chagos Archipelago; the long-term, continued  and effective operation of the military base at Diego Garcia; the protection of the area’s environment; and the return of Chagossians to other islands.

9. Personally, I believe an agreement is highly desirable, as soon as possible. The reason is simple: a failure to reach an agreement adversely impacts the reputation of the United Kingdom and its influence around the world and, even more directly, risks jeopardizing the operation of the base and related activities.

10. If the United Kingdom fails to reach an agreement with Mauritius, the consequences that will follow include:

1. grave reputational harm to the UK as a promoter of the rule of law, as the UK will be regarded around the world and by the United Nations as being in illegal occupation of a part of the territory of Mauritius and of Africa, and to be operating a military base at Diego Garcia in manifest violation of international law;
2. grave reputational harm to the UK as a reliable partner, having undertaken in September 2022 to reach an agreement with Mauritius based on respect for international law (as reflected in decisions of the ICJ, ITLOS and the UN);
3. most likely an immediate resumption by Mauritius of diplomatic and legal initiatives, including:

1. further resolutions adopted by the UNGA, the African Union and the Non-Aligned Movement that condemn Britain for its lawless posture;
2. further initiatives at other UN specialised agencies, which will require members to ignore all UK actions in relation to “BIOT” (as has already happened at the Food and Agriculture Organization and the Universal Postal Union, in relation to fisheries and stamps); and
3. further litigation before international courts and tribunals, with legally binding consequences, to ensure that the UK takes no measures that seek to prevent Mauritius from exercising its sovereignty over the Chagos Archipelago.

4. Permanently undermining the ability of the UK to have a judge elected to the ICJ (it lost its judge in 2017, for the first time since the ICJ’s creation in 1946, in part due to the UK’s lawless position on the Chagos Archipelago, following the General Assembly’s request for an Advisory Opinion from the ICJ);

5. issues with India (perhaps also in relation to the desired Free Trade Agreement), an ally of both Mauritius and the UK which is strongly committed to an early  resolution of the Chagos Archipelago matter on the basis of the authoritative determinations of the ICJ;

6. issues with the US, which wishes to secure the long-term future of the base and to avoid any further international litigation in relation to the Chagos Archipelago; 

7. issues with the global south and other partners, including the African Union and the Non-Aligned Movement, as well as the European Union, which will see the UK as holding others to standards which it does not apply to itself;

8. undermining the ability of the UK effectively to confront Russia (in relation to its illegal occupation of parts of Ukraine) and China (in relation to its unlawful claims in relation to the South China Sea) (both countries frequently invoke the UK’s position on the Chagos Archipelago to label the UK as a double-standard country);

9. difficulties consequential to the operation of the military base at Diego Garcia, which will be seen as operating illegally, which could give rise to difficulties with third countries, particularly in Asia and the Indo-Pacific region, in relation to supply chains which are connected to, or otherwise premised on, the lawful operation of the base at Diego Garcia;

10. reputational harm to the UK as a promoter of human rights, as the failure to allow the timely and immediate return of the Chagossians forcibly removed between 1968 and 1973 will surely cause Human Rights Watch and other groups to renew and develop claims that the UK and the US are engaged in a ‘crime against humanity’, with consequential legal risks for individuals considered to be responsible for the failure to reach an agreement with Mauritius; and
11. undermining the long-term protection of the marine environment of the Chagos Archipelago, together with effective scientific research, that can only be offered by a lawful Marine Protected Area established under Mauritian law, and losing out on the possibility of the full involvement of the UK and British organisations and scientists in the vital marine conservation work to be done in and around the Chagos Archipelago.
10. As regards the issue of China, I have read with incredulity and the most serious concern the absurd suggestion that Mauritius might enter into an arrangement with China. This comes from individuals and organisations who seem to have no insight or understanding as to political realities in that region. In my view, there is no possibility of that happening. First, Mauritius’ closest ally is India, and for this reason alone it is impossible to imagine such a scenario. Second, Mauritius has many islands, and if it wished to make one of them available to any other State hostile to the UK or the US, it could have already done so. The reality, as every informed observer knows, is that Mauritius has excellent relations with the UK and the US. It has consistently made clear – at the ICJ, ITLOS and the UN – that the base at Diego Garcia under Mauritian sovereignty will continue. Those who assert otherwise have offered not a shred of evidence to support this pernicious suggestion. If anything, it is the failure to secure an agreement in the immediate future that will undermine the excellent relations between Mauritius and the UK. In that regard, I deeply regret the failure of the Foreign Secretary to make clear that Mauritius has been a steady and reliable ally of the UK, and that it has consistently supported the continuation of the base. This failure, which is both unfortunate and potentially consequential, is evidenced most recently in his appearance before the Foreign Affairs Committee on 9 January 2024.

12. One final point should be emphasised: an agreement between Mauritius and the UK will have no consequences for any other UK overseas territory. The circumstances in which the ICJ, ITLOS and the UN have proceeded is premised on the unique situation of Mauritius, the only former UK colony in which a part of the territory was separated and retained prior to the granting of independence, in 1968. The factual and legal situation for every other UK OT (including the Falklands and Gibraltar), as well as the Sovereign Base Areas, is completely different and distinguishable, as anyone with even the most rudimentary knowledge of international law recognises. It is ill-informed and wholly misleading to suggest otherwise.

13. In summary, I can see no reason why the United Kingdom would not wish to enter into an agreement which provides long term security for the base at Diego Garcia, protection of the marine environment, respect for the rule of law, and the ability for the Chagossians to return. That is the agreement that is being negotiated. A British Government that turns its back on such an agreement would do the United Kingdom a grave and damaging disservice.

14. I would be pleased to provide such further information as may assist the Sub-Committee.

26 January 2024

Professor Philippe Sands KC FBA(Hon) FRSL

University College London

11 King’s Bench Walk

ANNEX

January 2024