US Reverses Stance on Chagos Islands, Risking Diego Garcia's Future

The future of the Chagos Islands has become a growing point of tension between the US and the UK. Originally, Washington backed a 2025 deal returning sovereignty to Mauritius while keeping a US lease on Diego Garcia. But in early 2026, the US sharply reversed its position, calling the agreement a strategic blunder.

At the heart of the dispute lies Diego Garcia, a key US military base often called an 'unsinkable aircraft carrier'. The shift in stance now threatens US security interests and raises questions about the islands' legal status.

In 2019, the International Court of Justice issued a non-binding advisory opinion on the UK's detachment of the Chagos Islands from Mauritius in 1965. Initially, the US under President Biden supported the UK's May 2025 deal, which would return sovereignty to Mauritius while securing a 99-year lease for Diego Garcia. Then-Secretary Rubio even praised it as a 'monumental achievement'.

By January 2026, however, President Trump condemned the agreement as an 'act of great stupidity'. He argued it signalled weakness to China and Russia, given Mauritius' growing ties with Beijing. The US now fears losing control of Diego Garcia, a critical military hub in the Indian Ocean.

The US Ambassador to the UK, Warren A. Stephens, had previously called the transfer the 'best available option'. Yet concerns persist over the legal fragility of the lease arrangements. The UN Committee on the Elimination of Racial Discrimination has also criticised the Mauritius Treaty for ethical failings, urging both the UK and Mauritius not to ratify it.

A potential alternative has emerged: a self-determination referendum for the Chagossian people. If they vote to become a resettled US Overseas Territory, the legal status of all the islands—including Diego Garcia—would be secured. This solution could bring four key benefits for the US: preserving UK sovereignty, correcting a historical injustice, redirecting funds to NATO, and bolstering the UK's moral standing.

Despite these options, the US has made clear it will defend its military base by force if needed. The dilemma remains—balancing strategic interests with the ethical and legal complexities of the islands' future.

The US now faces a difficult choice over the Chagos Islands. Its reversal from supporting the 2025 deal to outright opposition reflects deeper concerns about security and influence. With Diego Garcia's future uncertain, the focus shifts to whether a Chagossian referendum could offer a stable resolution—or if the dispute will escalate further.