The 2026 Chagos Sovereignty Accord: A New Chapter in Indian Ocean Decolonization

The formalization of the 2026 Chagos Sovereignty Accord marks a watershed moment in the history of decolonization and international law. The treaty, signed between the United Kingdom and Mauritius, provides for the phased transfer of sovereignty over the Chagos Archipelago to Mauritius, effectively ending more than half a century of British colonial administration in the Indian Ocean.

The dispute dates back to 1965, when the UK excised the Chagos Islands from Mauritius—then a British colony—to create the British Indian Ocean Territory (BIOT). This was followed by the forced displacement of the local Chagossian population to make way for a strategic military base on Diego Garcia, leased to the United States. For decades, Mauritius challenged this excision, gaining significant momentum after a 2019 advisory opinion from the International Court of Justice (ICJ) and a 2021 ruling by the International Tribunal for the Law of the Sea (ITLOS), both of which declared the UK's occupation illegal.

The 2026 Accord represents a pragmatic diplomatic solution. While Mauritius gains full sovereignty, the treaty ensures the continued operation of the Diego Garcia base under a 99-year lease, addressing the security concerns of the UK and the US in the Indo-Pacific. Furthermore, the agreement establishes a framework for the resettlement of displaced Chagossians on islands other than Diego Garcia, addressing a long-standing human rights grievance.

For India, the resolution is a welcome development. India has consistently supported Mauritius’ sovereignty claims while maintaining a close strategic partnership with the US and UK. The treaty stabilizes the geopolitical landscape of the Indian Ocean, aligning with India’s vision of a "Free, Open, and Inclusive Indo-Pacific" and its SAGAR (Security and Growth for All in the Region) policy.