What’s the Controversial UK Chagos Islands Deal and Why Did Trump Criticize It?

The ongoing geopolitical tensions surrounding the Chagos Islands highlight a significant shift in sovereignty from the UK to Mauritius, albeit with a long-term lease of Diego Garcia back to the UK. This deal, valued at £3.4 billion, has sparked controversy, particularly with US President Donald Trump's recent remarks deeming the plan an "act of GREAT STUPIDITY." The situation is complex, with implications for international relations, military strategy, and historical grievances.

Last updated: 28 October 2023 (BST)

What’s happening now

The UK's intention to return sovereignty of the Chagos Islands to Mauritius has reignited discussions about colonial legacies and military strategy. Although an agreement was reached in May 2025, the deal has yet to be ratified by the UK Parliament, leaving the islands as British territory for now. President Trump's recent condemnation of the plan contrasts sharply with his previous support, raising questions about political motivations and the future of US-UK relations.

Key takeaways

The UK aims to return sovereignty of the Chagos Islands to Mauritius while retaining a long-term lease on Diego Garcia.
Trump's comments have created confusion regarding the US-UK alliance and military strategy in the region.
The deal includes a £40 million trust fund for Chagossians affected by the historical displacement.

Timeline: how we got here

The history of the Chagos Islands is deeply intertwined with colonialism and military strategy. Key milestones include:

1965: The islands were separated from Mauritius while still under British colonial rule.
1966: The US established a military base on Diego Garcia after the UK forcibly removed the Chagossian population.
May 2025: The UK and Mauritius agreed on a deal to return sovereignty, which includes leasing Diego Garcia for 99 years.
January 2026: Trump publicly criticises the agreement, calling it "an act of total weakness."

What’s new vs what’s known

New today/this week

Trump's recent statements have cast doubt on the future of the lease agreement and the strategic value of Diego Garcia, which serves as a crucial military asset for the US. His comments suggest a potential shift in US policy towards the UK, particularly in relation to military bases.

What was already established

The agreement to hand over sovereignty was celebrated by Mauritius as a significant step towards decolonisation, and the UK government had previously defended the necessity of maintaining a military presence in the region to counteract "malign influence."

Impact for the UK

Consumers and households

The implications of this sovereignty transfer may not directly affect UK households in the short term. However, the geopolitical landscape could influence defence spending and international relationships, potentially impacting economic stability.

Businesses and jobs

Businesses linked to defence contracting may see changes depending on the outcomes of the lease negotiations. The strategic importance of Diego Garcia suggests that any disruptions could affect jobs and supply chains related to military operations.

Policy and regulation

The UK government will need to navigate the complexities of this agreement and its ratification process through Parliament. The evolving relationship with the US and the implications of Trump's comments will likely be a focal point in future discussions about military and foreign policy.

Numbers that matter

£3.4 billion: The estimated value of the lease agreement for Diego Garcia.
99 years: The duration of the lease for the military base on Diego Garcia.
£101 million: The average annual cost of leasing Diego Garcia.
£40 million: The trust fund established to support displaced Chagossians.

Definitions and jargon buster

Chagos Islands: A group of islands in the Indian Ocean that are part of the British Indian Ocean Territory.
Diego Garcia: The largest island in the Chagos Archipelago, home to a significant US military base.
De-colonisation: The process of transferring sovereignty from colonial powers to indigenous populations or nations.

How to think about the next steps

Near term (0–4 weeks)

UK Parliament is expected to debate the ratification of the sovereignty transfer. Observers should watch for any statements from government officials regarding the timeline and implications of this deal.

Medium term (1–6 months)

The UK will need to clarify its military commitments and relationships with both the US and Mauritius. Monitoring the political responses from both countries will be crucial to understanding future diplomatic relations.

Signals to watch

Parliamentary discussions and votes on the sovereignty transfer.
Statements from US officials regarding military commitments in the region.
Public responses from Chagossians and Mauritian officials regarding the implementation of the treaty.

Practical guidance

Do

Stay informed about developments in UK-Mauritius relations and their implications for the Chagos Islands.
Consider the historical context of colonialism when discussing the sovereignty transfer.

Don’t

Don’t assume the deal will be ratified without parliamentary debate and public scrutiny.
Don’t overlook the potential impact on the Chagossian community and their ongoing struggles for recognition.

Checklist

Review the details of the sovereignty agreement and its terms.
Follow news updates on political reactions in the UK and Mauritius.
Stay alert for parliamentary sessions discussing the ratification.
Understand the historical significance of the Chagos Islands for both the UK and Mauritius.

Risks, caveats, and uncertainties

The situation surrounding the Chagos Islands remains fluid, with multiple stakeholders involved. The potential for changes in US foreign policy under Trump could alter the dynamics of the lease agreement. Additionally, the reaction from the Chagossian community could impact public opinion and political pressure on the UK government.

Bottom line

The sovereignty transfer of the Chagos Islands to Mauritius represents a complex intersection of historical grievances, geopolitical strategy, and international relations. Observers should remain vigilant about developments in this area, as the implications could reverberate through both military and diplomatic channels.

FAQs

What is the significance of the Chagos Islands?

The Chagos Islands are strategically important due to the US military base on Diego Garcia, which plays a critical role in global military operations.

Why did the UK separate the Chagos Islands from Mauritius?

The separation occurred in 1965 under British colonial rule, and Mauritius argues it was forced to relinquish sovereignty as part of its independence deal.

What are the financial terms of the lease for Diego Garcia?

The agreement includes a 99-year lease with an average cost of £101 million per year, with initial payments of £165 million for the first three years.