Archive · 22 Sep 2026
Diego Garcia Deal Stalls Amid Britain-Mauritius-US Dispute
Diego Garcia is a remote island in the Indian Ocean with an important military base.
Britain currently controls the island, but Mauritius says the islands should belong to it.
Britain and Mauritius signed a deal to transfer sovereignty to Mauritius.
The deal would let Britain and the United States keep using the military base for 99 years.
The United Kingdom would also pay Mauritius £101 million each year.
The agreement has not been finalized because the United States has raised objections.
The base is important because it helps military operations in several regions.
Iran tried to hit the base with missiles in March, but the missiles did not hit it.
Britain plans to transfer sovereignty over the Chagos Archipelago, including Diego Garcia, to Mauritius.
A May 2025 treaty would give Mauritius sovereignty while allowing Britain and the United States to operate the base for 99 years.
The agreement includes annual UK payments of £101 million to Mauritius and is estimated to be worth £3.4 billion.
The deal has stalled amid objections from US President Donald Trump, who called it a “big mistake.”
The base remains operational, despite its strategic importance and Iran’s unsuccessful March ballistic-missile attack.
- Who
- Britain, Mauritius, the United States and Chagossians are central to the dispute; Iran also targeted the base in March.
- What
- Britain and Mauritius are trying to implement a treaty transferring sovereignty over the Chagos Archipelago while preserving British and American use of Diego Garcia.
- When
- The islands were separated from Mauritius in 1965; the treaty was signed in May 2025; Iran attempted to strike the base in March.
- Where
- Diego Garcia is in the Chagos Archipelago in the Indian Ocean, roughly halfway between East Africa and Indonesia.
- Why
- Mauritius seeks control of the archipelago and recognition of Chagossian rights, while Britain and the United States seek to preserve access to a strategically important military base.
Mauritius and Chagossian Claims
British and American Security Concerns
Territorial control
Mauritius and Chagossian Claims
Mauritius argues that the Chagos Archipelago was unlawfully separated from it during decolonization and should be returned.
British and American Security Concerns
Britain has maintained control of the territory and is seeking terms that preserve its military rights on Diego Garcia.
Military base
Mauritius and Chagossian Claims
The sovereignty transfer should give Mauritius control over the surrounding territory while addressing the rights of Chagossians removed from the islands.
British and American Security Concerns
Britain and the United States want continued operation of the strategically important base, and the United States has objected to the proposed deal.
Strategic risk
Mauritius and Chagossian Claims
The dispute is primarily a decolonization and self-determination issue involving Mauritius and displaced Chagossians.
British and American Security Concerns
The United States has linked its concerns to China’s growing strategic presence in the Indian Ocean and the base’s role in regional military operations.
- Location
- Diego Garcia is the largest island in the Chagos Archipelago, which contains about 60 islands.
- Military facility
- The joint US-UK base has an airfield, deep-water port, and communications and surveillance infrastructure.
- Proposed sovereignty
- Mauritius would exercise sovereignty over the Chagos Archipelago, including Diego Garcia.
- Base access
- Britain would retain rights over the military base for 99 years, with Britain and the United States continuing to operate and maintain it.
- Financial terms
- The United Kingdom agreed to pay Mauritius £101 million annually; the deal’s total value is estimated at £3.4 billion.
- Legal context
- In 2019, the International Court of Justice said British administration of the Chagos Islands should end and the archipelago should be returned to Mauritius.
- Current status
- The treaty’s implementation remains unresolved, but existing UK-US arrangements and day-to-day base operations continue.