Trump once backed the Chagos deal. Now he calls it 'stupid': What drove his sudden reversal

The islands were administered by Britain along with Mauritius during the colonial period. Before granting Mauritius independence in 1965, the UK separated Chagos and retained control.

US President Trump criticized the UK’s decision to transfer the Chagos Islands to Mauritius, calling it “GREAT STUPIDITY” and linking it to his push for the US to acquire Greenland, sparking tensions with European allies and political debate in Britain.

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US President Donald Trump has sharply criticised the United Kingdom over its decision to hand over the Chagos Islands to Mauritius, calling the move an “act of GREAT STUPIDITY” and linking it directly to his push for the United States to acquire Greenland.

Trump’s remarks mark a significant reversal from his earlier support for the Chagos agreement and have injected fresh tension into already strained transatlantic relations, particularly as he threatens European allies with tariffs over Greenland.

What are the Chagos Islands and why do they matter

The Chagos Archipelago is a chain of islands in the Indian Ocean, located roughly 500 kilometres south of the Maldives. The most strategically important island is Diego Garcia, which hosts a major joint US-UK military base.

The islands were administered by Britain along with Mauritius during the colonial period. Before granting Mauritius independence in 1965, the UK separated Chagos and retained control. To establish the military base, Britain forcibly removed between 1,500 and 2,000 Chagossians from the islands in the late 1960s and early 1970s. They were resettled in Mauritius and Seychelles and have never been allowed to return.

Mauritius has long argued that Britain illegally broke up its territory and that Chagos should be returned. International legal bodies have backed this position, including the International Court of Justice in 2019, which ruled that Britain’s control of the islands was unlawful and that they should be handed back as quickly as possible. The UN General Assembly also voted in favour of Mauritius, with India among the countries supporting its claim.

What is the Chagos deal

In May 2025, the UK agreed to transfer sovereignty of the Chagos Islands to Mauritius under a $4 billion agreement. However, Britain retained effective control over Diego Garcia through a long-term lease arrangement.

Under the deal, the UK will lease Diego Garcia from Mauritius for 99 years at an annual cost of $118 million, ensuring continued operation of the US-UK military base. The base has been used in operations ranging from the war in Afghanistan to strikes against Houthi targets in Yemen and humanitarian missions to Gaza.

At the time, the deal was strongly supported by Washington. US Secretary of State Marco Rubio called it a “monumental achievement” and said it reflected the strength of the US-UK relationship.

Trump himself appeared supportive. “They’re talking about a very long-term, powerful lease, a very strong lease, about 140 years actually,” he said earlier. “That’s a long time, and I think we’ll be inclined to go along with your country.”

Trump’s sudden reversal

Trump has now taken a dramatically different stance. In a social media post, he accused Britain of weakening Western security.

“Shockingly, our brilliant Nato ally, the United Kingdom, is currently planning to give away the island of Diego Garcia, the site of a vital US military base, to Mauritius,” Trump wrote.

“There is no doubt that China and Russia have noticed this act of total weakness. These are international powers who only recognise STRENGTH,” he added.

Trump then tied the Chagos decision to his demand for Greenland. “The UK giving away extremely important land is an act of GREAT STUPIDITY, and is another in a very long line of national security reasons why Greenland has to be acquired,” he said.

Trump has threatened Denmark and other European allies with tariffs unless the US is allowed to buy Greenland, arguing that the Arctic territory is essential for American national security.

Britain pushes back

British Prime Minister Keir Starmer has sought to calm the situation while firmly rejecting Trump’s Greenland demand.

“On Greenland, the right way to approach an issue of this seriousness is through calm discussion between allies,” Starmer said. “Any decision about the future status of Greenland belongs to the people of Greenland and the Kingdom of Denmark alone.”

UK officials have insisted Trump’s comments will not derail the Chagos agreement. Darren Jones, Chief Secretary to the Treasury, said the deal was already complete.

“We’ve done a deal with the Mauritian government, we’ve legislated for the process, we’ve agreed the terms of the treaty, which has been signed,” Jones told Sky News.

“This is the way in which to secure that military base for the next 100 years,” he said, adding that “British diplomacy is working.”

Political backlash at home

Trump’s criticism has fuelled political debate in Britain. Conservative leader Kemi Badenoch described the Chagos deal as “complete self-sabotage”.

“I’ve been clear, and unfortunately on this issue President Trump is right,” she wrote on X. “Keir Starmer’s plan to give away the Chagos Islands is a terrible policy that weakens UK security.”

Liberal Democrat leader Ed Davey took the opposite view, arguing Starmer had been too accommodating to Trump. “It’s time for the government to stand up to Trump; appeasing a bully never works,” Davey said.

As Trump continues to link Greenland, tariffs and the Chagos deal, Britain and its European allies now face growing uncertainty over how far the US president is willing to go to force concessions from even his closest partners.