UK Cedes Chagos Islands to Mauritius in Historic Sovereignty Deal

On May 22, 2025, British Prime Minister Sir Keir Starmer formalized an agreement transferring sovereignty of the Chagos Archipelago to Mauritius. This pivotal) decision brings to a close one of the longest-running post-colonial territorial disputes. While sovereignty over the islands has shifted, the United Kingdom will maintain a presence on Diego Garcia a critical military installation through a 99-year lease agreement, paying Mauritius £101 million annually, amounting to a total of £3.4 billion over the term.

Background: A Disputed Legacy

The Chagos Islands, located in the continent of Africa, situated in the Indian Ocean, were detached from Mauritius in 1965 during British colonial rule and reclassified as the British Indian Ocean Territory (BIOT). In the years that followed, from 1968 to 1973, the UK government forcibly evicted the native Chagossian population to pave the way for a joint US-UK military base on Diego Garcia. This controversial act has faced widespread international condemnation and legal scrutiny.

In 2019, the International Court of Justice (ICJ) issued a non-binding opinion asserting that the UK’s continued administration of the islands was unlawful and called for their return to Mauritius. The UN General Assembly reinforced this view, urging Britain to end its occupation of the territory.

The 2025 Deal: Terms and Strategic Considerations

The newly signed treaty recognizes Mauritius as the rightful sovereign over the Chagos Islands. Nevertheless, the UK will retain control of the Diego Garcia base, considered essential to Western defense operations in the Indian Ocean, under the terms of the long-term lease.

Sir Keir Starmer defended the arrangement, framing it as a pragmatic compromise that safeguards national and allied security interests while complying with global legal expectations. He also noted that the financial terms represent a cost-effective alternative to building or relocating such a strategic facility.

Responses: Divided Opinions and Unresolved Issues

Displaced Chagossians: Members of the Chagossian diaspora, many of whom were forced from their homes decades ago, have voiced strong discontent. They argue the agreement overlooks their rights and aspirations particularly the long-standing demand for the right to return. Bertrice Pompe, a prominent Chagossian activist born on Diego Garcia, launched a legal bid to halt the deal, calling it an abandonment of the community’s interests.

Domestic Political Reactions: Critics within the UK, especially from the Conservative opposition, have condemned the deal. They claim it may expose British assets to future diplomatic risk, particularly in light of Mauritius’s increasing economic engagement with China. Some also argue the financial cost is unjustified amid broader budgetary pressures.

Global Support: Despite domestic pushback, the deal has drawn praise from several international partners, including the United States, Canada, Australia, and New Zealand. These allies see the move as a meaningful step toward post-colonial reconciliation and a way to maintain the strategic balance in a region of growing geopolitical competition.

Conclusion: A Milestone with Complex Consequences

This agreement represents a turning point in the UK’s colonial legacy, aligning its policies with international rulings while preserving vital security partnerships. However, the deal also exposes lingering tensions especially the unresolved plight of the Chagossian people and the strategic uncertainty surrounding rising regional influences. How these challenges are addressed in the coming years will shape the legacy of this unprecedented handover.

Written By: Kehinde Samson