LONDON — Keir Starmer has successfully won Donald Trump back around to supporting his controversial Chagos Islands deal, rescuing a key foreign policy goal that the U.S. president blasted last month as an “act of GREAT STUPIDITY.”

The U.K. prime minister’s plan to hand over sovereignty of the archipelago in the Indian Ocean to Mauritius while retaining use of a joint U.S.-U.K. military base on the island of Diego Garcia was thrown into disarray a fortnight ago by the president’s surprise criticism.

But Trump wrote Thursday on Truth Social, the same platform where he had unleashed his criticism, that he now understands it’s the best deal Britain was able to get after he had “very productive discussions” with Starmer — though he warned he wouldn’t hesitate to get involved if he felt U.S. interests were at risk.  

“If the lease deal, sometime in the future, ever falls apart, or anyone threatens or endangers U.S. operations and forces at our Base, I retain the right to Militarily secure and reinforce the American presence in Diego Garcia,” the president added. 

To the ire of British officials, Reform UK leader Nigel Farage and the Conservatives’ Kemi Badenoch had lobbied Trump to oppose the deal, which will cost Britain around £3.4 billion over the initial 99-year lease. 

But official diplomatic channels have won the debate, and Starmer will take Trump’s backing as a modicum of sweet relief during a dire moment in which his authority is being questioned.

Government officials, speaking under condition of anonymity to avoid further fraying diplomatic relations, had ascribed Trump’s Jan. 20 criticism of the Chagos deal to Starmer’s public defense of Greenland from American threats to seize the Danish territory.

Starmer broached the agreement with Trump in a call over the weekend, as well as during another on Thursday. 

Downing Street’s account of the call said the leaders had “agreed on the importance of the deal to secure the joint U.K.–U.S. base on Diego Garcia, which remains vital to shared security interests.”

The men also agreed that both sides would “continue to work closely on the implementation of the deal,” the statement added.