Chagos Islands: dispute, Diego Garcia and the 2024 UK–Mauritius agreement
Introduction
The Chagos Islands are at the centre of a complex dispute with strategic, legal and human consequences. The archipelago, coterminous with the British Indian Ocean Territory (BIOT), hosts the American military base on Diego Garcia and has been claimed by Mauritius. Recent diplomatic developments, contested maritime claims and questions over the rights of the displaced Chagossians make the islands a matter of regional and international relevance.
Main developments and background
Historical and territorial context
The Chagos Islands were detached from Mauritius in 1965 and have been administered as the British Indian Ocean Territory. The largest island, Diego Garcia, has been the site of a joint UK–US military base since the 1970s, giving the archipelago outsized strategic importance.
Sovereignty claims and maritime disputes
Mauritius claims sovereignty over the Chagos Archipelago, which is coterminous with the BIOT. The Maldives has challenged aspects of the UK’s maritime claims, stating that the UK’s assertion of a 200‑nautical‑mile Exclusive Economic Zone around the Chagos Archipelago is invalid on the grounds that the islands are considered uninhabited (clarification has been noted in source material). A separate but related controversy has concerned the UK Government’s 1 April 2010 declaration of the BIOT as a Marine Protected Area (MPA), which prohibited fishing and extractive activities including oil and gas exploration and met with opposition from Mauritius.
2024 agreement and military arrangements
On 3 October 2024 the UK Government and the Mauritian government issued a joint statement saying they had negotiated for the sovereignty of the Chagos Islands after two years of talks, while ensuring the continued operation of the American military base on Diego Garcia. That statement also effectively ruled out the right of return of Chagossians to Diego Garcia.
Recent political fallout
Commentary and reporting in 2026 have highlighted the sensitivity of the handover and its potential impact on the UK–US relationship and domestic politics. Coverage has noted that shifting signals from US political figures have complicated the position of the UK government and provoked debate about the future of the special relationship and the strategic role of Diego Garcia.
Conclusion
The Chagos Islands dispute combines strategic military interests, competing sovereignty claims and unresolved human rights issues for displaced Chagossians. The 2024 UK–Mauritius agreement and the continuing presence of the Diego Garcia base mean the islands will remain a focal point for diplomatic negotiation and regional concern. For readers, the situation underscores how geopolitical priorities, environmental designations and historical claims can intersect to produce enduring international tensions.
