Background:

The Chagos Archipelago, a remote group of over 60 islands in the Indian Ocean, has been at the center of a decades-long sovereignty dispute between the United Kingdom and Mauritius. The UK separated the islands from Mauritius in 1965, three years before Mauritius gained independence, and established the British Indian Ocean Territory (BIOT).

In the 1970s, the UK allowed the United States to build a military base on Diego Garcia, the largest island in the archipelago. The local Chagossian population was displaced, leading to international criticism and legal challenges.

Recent Development

In May 2025, the UK government, led by Prime Minister Keir Starmer, agreed to transfer sovereignty of the Chagos Islands to Mauritius. The agreement follows the 2019 advisory opinion of the International Court of Justice (ICJ) and United Nations resolutions urging the UK to end its colonial administration of the islands.

Key Provisions of the Treaty

• Sovereignty Transfer: Mauritius regains control over the Chagos Archipelago, including Diego Garcia.
• Lease Agreement: The UK will lease back Diego Garcia from Mauritius for 99 years, paying approximately:
  • £101–136 million annually, totaling over £3 billion ($4 billion) across the lease term.
• Strategic Base Retained: The US-UK military base on Diego Garcia will continue operating. It is vital for counter-terrorism, surveillance, and regional stability in South Asia, the Middle East, and East Africa.

Geographical Significance

• The Chagos Islands lie about 500 km south of the Maldives and are part of the Chagos–Laccadive Ridge.
• It is the southernmost archipelago of the ridge and is located over 9,000 km southeast of the UK.
• Major islands: Salomon Islands, PerosBanhos, Diego Garcia.

Strategic and Military Importance

• Diego Garcia serves as a key US military outpost, supporting operations in multiple global regions.
• Described as an “almost indispensable platform”, the base has hosted long-range bombers and surveillance missions.
• Recently, it has been used for nuclear-capable bomber deployments and airstrike missions.

Local and International Reactions

• Mauritius: The agreement is celebrated as the completion of its decolonisation process. Chagossian exiles expressed joy over the chance to return to their ancestral lands.
• India: Strongly supported the sovereignty restoration, aligning with its principles on decolonisation, sovereignty, and territorial integrity. India views the resolution as a positive development for Indian Ocean regional stability.

India’s Official Statement

“India welcomes the resolution of the Chagos dispute, a significant step in completing Mauritius’s decolonisation in accordance with international law and a rules-based order. India remains committed to maritime security and prosperity in the Indian Ocean region.” – Ministry of External Affairs, May 2025

Criticism and Concerns

• Some UK opposition leaders raised concerns about national security and financial burden on taxpayers.
• There are apprehensions about Mauritius’s close trade ties with China, though the deal includes safeguards against “malign influence.”