Trump's Ire, UK's Defence: What Is The Big 'Deal' About The Chagos Islands Returning To Mauritius?

Last Updated:January 20, 2026, 18:09 IST

Britain ceded sovereignty of the islands to Mauritius in a multi-billion dollar deal, in which it secured a lease for the key UK-US airbase on Diego Garcia over the next century

London said its deal to hand the Chagos Islands to Mauritius "secures" the key US-UK Diego Garcia military base on the Indian Ocean archipelago, after President Donald Trump accused Britain of "great stupidity". (Image: AFP/File)

“An act of total weakness" – this is how US President Donald Trump described Britain’s deal to cede sovereignty of the island of Diego Garcia in the Chagos Islands to Mauritius.

Britain signed the multi-billion dollar deal – securing a lease for the strategically important UK-US airbase on Diego Garcia over the next century – eight months ago but the contentious agreement is once again in the spotlight.

Despite the deal being framed as a resolution to a decades-long legal dispute, it has triggered a firestorm of international criticism and domestic debate, highlighting a growing tension between traditional diplomacy and a more transactional approach to global security.

Here is all you need to know about the islands and the deal:

WHAT ARE THE CHAGOS ISLANDS?

The Chagos Archipelago is a cluster of six atolls comprising more than 600 islands in the Indian Ocean.

Located approximately 500 km south of the Maldives and halfway between Africa and Indonesia, this strategically vital territory was at the heart of a landmark 2025 agreement where Britain ceded sovereignty to Mauritius while securing a 99-year lease for the joint UK-US military base on Diego Garcia.

At least 4,000 people are stationed on the islands. No indigenous inhabitants, often referred to as Chagossians or Ilois, have lived there since Britain forcibly displaced up to 2,000 people, mostly former agricultural workers, in the late 1960s and early 1970s to establish the Diego Garcia base.

WHAT IS BRITAIN’S DEAL WITH MAURITIUS?

According to a report published by Reuters, under increasing international pressure, Britain agreed in October 2024 to transfer sovereignty of the Chagos Islands to Mauritius – a former colony that gained independence in 1968.

The deal, however, drew criticism from lawmakers as well as Britons born in Diego Garcia. In May 2025, Britain said it will pay Mauritius 101 million pounds ($136 million) per year – calculated to be worth 3.4 billion pounds over the lifetime of the deal – to secure the future of the Diego Garcia military base under a 99-year lease.

At the time, the US said it “welcomed the historic agreement", commending both countries’ leaders for their vision. In February 2025, ahead of the signing, Trump also expressed preliminary support for the deal.

Canada, Australia, New Zealand and India have also backed the agreement.

WHAT IS THE SIGNIFICANCE OF THE DIEGO GARCIA BASE?

Diego Garcia serves as a key military base in the Indian Ocean for the US and Britain.

Reuters reported that recent operations launched from there include bombing strikes against Houthi targets in Yemen in 2024 and 2025, humanitarian aid deployments to Gaza and attacks against Taliban and al Qaeda targets in Afghanistan in 2001.

China also has a growing reach in the region, including close trade ties with Mauritius.

WHAT ARE THE CONCERNS, THE UN VIEW?

United States Secretary of State Marco Rubio raised concerns in February 2025 about potential threats to his country’s security, particularly in light of Chinese influence.

Even Mauritian Prime Minister Navin Ramgoolam, who was elected after the initial agreement was reached, questioned the deal and had wanted Trump to assess the plan. Some Chagossians, many of whom ended up living in Britain after being removed from the archipelago, have protested against the agreement on the grounds that they were not consulted.

Kemi Badenoch, leader of the opposition in Britain, said on Tuesday on X that the deal was “complete self sabotage" that made “us and our NATO allies weaker".

Britain had split the archipelago off from its colonial island territory of Mauritius in 1965, three years before granting independence to Mauritius but without the islands.

In 2019 after a request by the United Nations General Assembly, the Court of Justice issued a non-binding ruling calling on Britain to give up control, saying it wrongfully forced the population to leave to make way for the base.

WHAT WAS THE LEGAL CHALLENGE?

Before the deal was signed, a UK High Court judge issued a last-minute injunction sought by Bernadette Dugasse and Bertrice Pompe, British nationals who were born in Diego Garcia and criticised the deal for excluding Chagossians. The injunction, however, was overturned hours later making way for the deal to be signed.

WHAT DOES IT HAVE TO DO WITH TRUMP’S GREENLAND ULTIMATUM?

The transition of sovereignty of the Chagos Islands was originally a move that enjoyed broad international support.

Under the previous Biden administration, the US “welcomed the historic agreement", praising the vision of both British and Mauritian leaders for resolving long-standing displacement claims and legal challenges. Other global allies, including India, Australia, Canada, New Zealand, Japan, and South Korea, also endorsed it as a necessary step to conclude the decolonisation process of Mauritius.

The diplomatic landscape, however, dramatically shifted following the return of Trump to the White House. Despite expressing preliminary support for the arrangement in early 2025, he has recently denounced the treaty as an “act of total weakness" and “great stupidity".

In a blunt post on his Truth Social platform, he claimed that the move provided China and Russia with an opening stressing that international powers “only recognize STRENGTH".

Most controversially, the US President has linked this perceived strategic failure in the Indian Ocean to his renewed demands for the US to acquire Greenland from Denmark. He argued that the loss of Chagos is another reason why acquiring Greenland is imperative for national security.

He has gone so far as to threaten European allies with tariffs – starting at 10 percent in February and rising to 25 percent by June – if they continue to resist his territorial ambitions regarding Greenland.

(With agency inputs)

News explainers Trump's Ire, UK's Defence: What Is The Big 'Deal' About The Chagos Islands Returning To Mauritius?

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