On May 22, 2025, the United Kingdom and Mauritius signed a landmark agreement transferring sovereignty of the Chagos Islands to Mauritius. This accord, however, allows the UK to retain control over the strategic military base on Diego Garcia through a 99-year lease. The deal, valued at £3.4 billion, includes annual payments and support packages but has sparked controversy over its implications for displaced Chagossians and regional geopolitics.
Historical Context
The Chagos Archipelago was detached from Mauritius in 1965, prior to Mauritius gaining independence in 1968. The UK established the British Indian Ocean Territory (BIOT) and, in the late 1960s and early 1970s, forcibly removed approximately 2,000 Chagossians to facilitate the construction of a US military base on Diego Garcia. This action has been widely condemned, with the International Court of Justice (ICJ) advising in 2019 that the UK’s continued administration of the Chagos Archipelago was unlawful and that the decolonization of Mauritius was not lawfully completed.
The 2025 Sovereignty Agreement
Under the terms of the 2025 agreement:
• Sovereignty Transfer: The UK agreed to transfer sovereignty of the Chagos Islands to Mauritius, excluding Diego Garcia.
• Leaseback Arrangement: The UK retains control over Diego Garcia through a 99-year lease, paying Mauritius £101 million annually, totaling £3.2 billion over the lease period.
• Economic Support: An additional £45 million annual economic support package and a £40 million trust fund for displaced Chagossians were established.
• Security Provisions: The agreement includes clauses restricting foreign military presence and development near the base, ensuring exclusive UK control over military and communications infrastructure.
Political Reactions and Criticisms
The agreement has elicited mixed reactions:
• Mauritian Government: Prime Minister Navin Ramgoolam, who assumed office shortly before the deal’s finalization, expressed reservations about the agreement’s terms, citing concerns over the benefits for Mauritius and the lack of transparency in negotiations.
• Chagossian Community: Displaced Chagossians have criticized the deal for excluding them from negotiations and failing to guarantee their right of return. Legal challenges were mounted but ultimately dismissed by the UK High Court.
• UK Political Opposition: Conservative politicians and others have denounced the agreement as a strategic misstep and a financial burden, questioning the £3.4 billion cost and the implications for UK sovereignty.
Geopolitical Implications
Diego Garcia remains a critical asset for US and UK military operations, serving as a strategic hub in the Indian Ocean. The leaseback ensures continued access for counterterrorism and regional security efforts. However, the agreement has raised concerns about regional dynamics, particularly regarding China’s growing influence and the potential for shifts in alliances.
The 2025 Chagos Islands agreement represents a significant development in the longstanding sovereignty dispute between the UK and Mauritius. While it marks progress in addressing historical injustices, the deal’s exclusion of Chagossian voices and the strategic considerations involved highlight the complexities of decolonization and international diplomacy. Ongoing scrutiny and dialogue will be essential to ensure that the rights and interests of all stakeholders are adequately addressed.