“By 2127, the US may no longer need a military base in the Indian Ocean,

while rising sea levels could make Diego Garcia inoperable”

Interview: David Snoxell – Coordinator of the Chagos Islands All-Party Parliamentary Group

* ‘The UK is not under US pressure over Chagos. The US Administration broadly supports the treaty; it is the President who opposes it’

After decades of controversy, Mauritius and the United Kingdom reached a treaty in May 2025 aimed at settling the sovereignty issue while safeguarding the long-term operation of the strategically important US military base on Diego Garcia. Yet the agreement has become caught in a new political impasse following President Donald Trump’s renewed criticism of the treaty. For Mauritius, sovereignty over the Chagos Archipelago is non-negotiable. For the UK, the challenge is to reconcile its commitment to the treaty and international law with its strategic relationship with Washington and the requirements of the Diego Garcia base. The treaty has also faced opposition from sections of the US political establishment, British conservative circles and some Chagossian groups, complicating its passage through the UK Parliament.

Against this background, Mauritius Times spoke to David Snoxell, former British High Commissioner to Mauritius and Coordinator of the Chagos Islands All-Party Parliamentary Group (APPG) in the UK Parliament. He discusses the APPG’s position, the prospects for ratification, the options available to London and Port Louis, and the wider implications for international law, the future of Diego Garcia and the Chagossians.

Mauritius Times: The Chagos Islands All-Party Parliamentary Group (APPG) in the UK Parliament has historically supported an overall diplomatic settlement between the UK and Mauritius grounded in international law. What is the APPG’s position in relation to recent developments surrounding the May 2025 UK–Mauritius Chagos Agreement, with US President Trump again publicly criticizing the treaty as a “terrible” and “ridiculous” arrangement? 

David Snoxell: On 3 November 2022 Mauritius and the UK announced that negotiations to conclude a treaty in keeping with international law would be concluded by early in the new year of 2023. This was not achieved, partly because of the timing of the three national elections in the UK (4 July 2024), the US (5 November 2024), and Mauritius (10 November 2024), as well as the differing objectives of the three new governments.

The Mauritian Prime Minister and President Trump commissioned reviews of the draft treaty. It was signed by the two Prime Ministers on 22 May 2025. From July 2024, the UK Parliament debated a Bill to implement the treaty. The Bill was paused in the House of Lords on 27 January 2026, at its final stage.

Although the treaty was supported by the US Administration and Presidents Biden and Trump, the latter abruptly changed his position to oppose the treaty. The UK Government’s view is that the treaty cannot be ratified without US agreement because the 1966 UK/US Exchange of Notes stipulates that the UK will remain sovereign over Chagos.

The media and conservative think tanks became heavily involved and critical of the treaty. Chasgossian groups in the UK also opposed the UK-Mauritius Treaty. This had its impact on politicians with the result that some members of the APPG no longer supported the Bill and Treaty. It has become a highly charged political debate that could have been avoided had the treaty been concluded and ratified before the three elections.

Clearly, a delay of nearly four years since the Conservative Foreign Secretary, James Cleverly, announced the negotiations has been the cause of the difficult situation in which the two governments and the APPG now find themselves. Because of the 2024 election, the APPG lost several members. Most members, including the chairman and vice-chairs, still support resettlement and a negotiated settlement with Mauritius as represented by the treaty. At its 104th meeting in June, the APPG decided to expand its purpose, which now reads: “To help bring about a resolution of the issues concerning the future of the Chagos Islands and the Chagossians, including a just and lasting framework for the resettlement of Chagossians wishing to do so.”

* Mauritian Prime Minister Navin Ramgoolam has firmly reaffirmed that Mauritian sovereignty over the Chagos Archipelago is strictly non-negotiable. Given Port Louis’s refusal to reopen the core treaty text, how much diplomatic manoeuvring space does London actually have to satisfy Washington?

The UK Government fully accepts that Chagos belongs to Mauritius. A way forward needs to be agreed between the UK and Mauritius if the treaty is to be ratified before President Trump leaves office on 20 January 2029. A further delay of two years and three months, until the next US administration takes office, would be difficult to manage.

By then, there could be three new governments, each with different ideas and policies, while the international situation may no longer be conducive to a final settlement. Getting the US President on board for a third time looks unlikely, although both governments will continue their efforts to win his support. 

* The May 2025 treaty relies on separating formal legal title (Mauritius) from long-term military administration (through a UK-US lease of Diego Garcia). From a diplomatic standpoint, is this framework robust enough to withstand continued political scrutiny in Washington and Westminster?  

From a diplomatic standpoint, the best way forward would be to secure the US President’s agreement to the UK ratifying the treaty without any changes to its text. Ratification could potentially be achieved through a minor amendment to the 1966 UK–US Exchange of Notes. If that proves impossible, the UK and Mauritius would need to consider what might persuade President Trump to change his position. There has been some discussion of Mauritius selling Diego Garcia to the US…

* That does not appear plausible from the Mauritian perspective. However, critics in the US argue that even a 99-year lease leaves some long-term operational uncertainty. Do you foresee any willingness in Port Louis to modify the lease-extension arrangements or provide additional guarantees to address Washington’s concerns about the long-term security of the base?

I don’t see any need at this stage to extend the 99-year lease. By 2127, the US may no longer need a military base in the Indian Ocean. Only last year they bombed Iran directly from the US. In any case, rising sea levels could make the base inoperable well before the end of the lease.

* If the main treaty can’t be reopened, could side-agreements or a joint UK–US–Mauritius security deal satisfy Washington?

My letter published in The Times on 30 September stated:  “Mathew Parris (‘Trump can solve our Chagos problem’ – 28 Sept) proposes a trilateral deal between the UK, US and Mauritius to resolve the current political impasse.”

Such an idea deserves consideration. It would enable Britain to honour its 1965 Lancaster House commitment to “return” Chagos to Mauritius – the Aldabra islands were returned to Seychelles in 1976 with US agreement. It would also uphold international law. The 56 Outer Islands, as Mauritian territory, would be available for resettlement by Chagossians.

Moreover, the move would release the UK from the considerable cost of administering a base we do not use. It would allow the Marine Protected Area to become internationally recognised and would give the US unfettered use of their military base on Diego Garcia in exchange for payment to Mauritius.

Answering a PQ on 11 July 1980, Prime Minister Thatcher said: “In the event of the islands no longer being required for defence purposes, they should revert to Mauritius.” This has been the policy of successive governments.

* In balancing its “Special Relationship” with the US against its obligations under International Court of Justice (ICJ) and UN General Assembly rulings, isn’t London effectively prioritizing American security demands over the international rules-based order?

The “Special Relationship” is much less visible in today’s world order, although the UK remains militarily dependent on the US and is bound by the 1966 Exchange of Notes with the US. However, that agreement will terminate in December 2036, just over a decade from now. I am sure neither side wants to wait that long for a settlement. The current British Government is also committed to respecting international law, UN General Assembly resolutions and ICJ rulings.

* But if the UK yields to US pressure and delays or indefinitely abandons implementation, what damage could this do to London’s credibility when it champions international law globally?

The UK is not under US pressure over Chagos. The US Administration and its agencies are generally supportive of the treaty; it is the President who is opposed to it. It is therefore for the UK and Mauritius to find a way of addressing his concerns.

UK officials and ministers remain in close contact with their American counterparts. Prime Minister Burnham has raised the issue with the President, and perhaps Prime Minister Ramgoolam has done so as well. In the past, the UK’s reputation for upholding international law and human rights has been damaged by its handling of the Chagos issue and the treatment of Chagossians.

* If the treaty stalls or falls apart, Mauritius will likely step up diplomatic pressure at the UN and ICJ, while using International Tribunal for the Law of the Sea (ITLOS) and the Permanent Court of Arbitration (PCA) to challenge UK authority over Chagos maritime zones, fisheries, and environmental permits. How effective do you think these legal avenues would be in practice, and could they force the UK back to the table?

No one will be surprised if Mauritius takes the issue back to the UNGA which in 2019 set a deadline of six months for the implementation of the ICJ Advisory Opinion or finds a way of going back to the ICJ and ITLOS.  The only answer the UK can give is that it is doing all it can to persuade the US to enable the UK to ratify the treaty. The UK will remain at the table.

The UK’s control of Chagos has been eroded by the decisions of the UNGA, ICJ and ITLOS. The Marine Protected Area is not currently recognised internationally amongst conservation organisations and the UN. It can no longer issue stamps and coins for the territory and will lose its position as a coastal state on the Indian Ocean Tuna Commission. A negotiated settlement becomes increasingly inevitable.

Mauritius Times ePaper Friday 2 October 2026