USA

The Chagos Islands: Where they are and why they are militarily important for the UK

Why is Diego Garcia in the Chagos Islands so important?

The Chagos Islands are important militarily because they host the strategically located Diego Garcia base.

Diego Garcia is the largest of 55 islands that form the Chagos Archipelago within the British Indian Ocean Territory (BIOT), following the French ceding control of many Indian Ocean islands to Britain under the 1814 Treaty of Paris.

The joint US-UK base is a significant hub for US naval and air operations.

The base, which supports US Navy supply ships and long-range bombers like the B1-B Lancer, gives a secure location from which operations can be launched to the Middle East.

The US base on Diego Garcia is sizable and is seen as very important to maintaining regional stability.

chagos islands — The UK bought the Chagos Islands for £3m to create the British Indian Ocean Territory in November 1965

There is a small detachment of UK personnel on the base, reportedly around 40 personnel, which provides police and customs services on the island.

Three hundred and ninety-six joint forces personnel and more than 2,000 Department of War civilians and contractors are based there.

The Chagos Islands timeline

November 1965: UK buys Chagos Islands for £3m to create the BIOT.

February 2019: A UN court says that the UK has an "obligation" to end its administration of the Chagos Islands "as rapidly as possible".

May 2019: The UN passes a non-binding resolution demanding that the UK end its control of the Chagos Islands.

November 2022: The UK and Mauritius agree to hold talks on the future of the Chagos Islands.

October 2024: The UK transfers the sovereignty of the Chagos Islands to Mauritius after more than 50 years of control.

December 2024: The UK government denies that there is a lack of US support for a deal over the islands.

January 2025: A former First Sea Lord, Admiral Lord West, backs a report calling on the UK government to halt a deal that will hand sovereignty of the Chagos Islands to Mauritius.

May 2025: A judge clears the way for the Government to sign its deal over the Chagos after discharging a High Court injunction which blocked the end of negotiations.

January 2026: US President Donald Trump criticises the UK-Chagos Islands deal, calling it an "act of great stupidity".