Starmer blocks US access to British bases for potential Iran strikes citing international law

Prime Minister Keir Starmer is blocking a request from US President Donald Trump to utilize British sovereign bases for potential aerial strikes against Iran, citing concerns that such an operation would violate international law.

According to reports from The Times, a deepening diplomatic rift has emerged as the Prime Minister informed President Trump that the United Kingdom will not grant permission for US assets to launch from the sovereign base on Diego Garcia or from RAF Fairford in Gloucestershire. These strategic installations serve as critical hubs for the US fleet of heavy bombers across Europe and the Indian Ocean.

Under the terms of long-standing bilateral agreements with Washington, these facilities may only be utilized for military operations against third-party nations with the prior explicit consent of the British government.

This refusal has reportedly prompted President Trump to withdraw his administration’s support for a landmark deal to transfer sovereignty of the Chagos Islands from the UK to Mauritius.

The President addressed the escalating tension regarding Iran and the United Kingdom’s role via a post on the social media platform Truth Social. He suggested that British support would be “legal under international law” because of the inherent threat an Iranian strike could pose to the UK itself.

“If Iran decides not to make a deal [regarding its nuclear program], the US may need to use the airfield located at Diego Garcia and Fairford to eliminate a potential attack by a highly unstable and dangerous regime,” the President stated.

On Thursday, President Trump indicated that the world would learn “probably within the next ten days” whether the US would reach a diplomatic accord with Tehran or pivot toward military intervention.

“We may or may not have to go a step further now. They cannot have a nuclear weapon. It is very simple. There can be no peace in the Middle East if they have nuclear weapons,” Trump asserted.

Government sources suggested that Britain remains unlikely to support a preemptive military strike, following London’s refusal last summer to participate in a presidential plan targeting Iranian nuclear facilities. In the wake of previous discussions regarding military action against Iran, ministers have repeatedly declined to confirm whether UK government lawyers believe such strikes meet the threshold of international legality.

The White House is understood to be drafting comprehensive military contingencies for an assault on Iran that would incorporate the use of Diego Garcia and RAF Fairford. Defense officials have reportedly briefed President Trump that following the largest military buildup in the region since the 2003 invasion of Iraq, US forces will be combat-ready by Saturday, Feb. 21.

“A political process supported by the UK continues between the US and Iran,” a government spokesperson said. “Iran must never be able to develop a nuclear weapon, and our priority remains security in the region.”

When questioned specifically on the use of British bases, the government maintained its standard protocol: “As a matter of routine, we do not comment on operational matters.”

Information obtained by The Times suggests that British officials fear granting base access would implicate the UK in a breach of international law. Specifically, they are concerned with statutes that do not distinguish between the state carrying out an illegal act and a supporting state that is “aware of the circumstances of the internationally wrongful act.”

President Trump spoke with Starmer on Tuesday night to discuss his ultimatum to Tehran regarding the nuclear program. The following day, the President issued a statement criticizing the Chagos sovereignty agreement.

In 2021, John Healey—the current Defense Secretary—sought clarification from the then-Conservative government while in opposition regarding the “red lines” for US forces using British bases. He was informed at the time that any proposed military operation must align with both UK domestic law and the British government’s interpretation of relevant international law.

The Conservative opposition is now urging Starmer to grant the US access. Shadow Defense Secretary James Cartlidge stated:

“Iran’s nuclear program poses a grave threat to the UK and our allies. If the US determines that further measures are required to deal with this specific threat, and we believe that such action is in our national interest and intended to protect the vital security interests of the UK, we should permit the use of our bases.”

Prior to the invasion of Iraq, then-Attorney General Lord Goldsmith argued that international law only permitted the use of force in self-defense during an actual or imminent attack. Goldsmith later contended that a UN resolution regarding Iraq rendered that specific conflict legal.

The government has repeatedly emphasized that the handover deal with Mauritius—which is projected to cost taxpayers £35 billion—is essential for security and would prevent a protracted and costly legal battle over the territory.

While President Trump initially appeared receptive to the plan, his stance shifted during recent debates concerning the future of Greenland. Senior government officials have described the current situation as “bleak,” noting that the Chagos agreement cannot feasibly proceed without American endorsement.

RAF Fairford and other British military installations were most recently utilized by the US last month during a military operation to seize the registered tanker Bella 1. However, that operation was conducted with the full support of the United Kingdom, with ministers affirming its justification under international law at the time.

On Thursday, Alex Davies-Jones, the Victims’ Commissioner, insisted that Starmer would “deliver” the deal and return the necessary legislation to Parliament as swiftly as possible.

Speaking to Times Radio, she said: “We will continue to work with our allies on this, including the Americans, but national security must be the priority above all else, and this government is committed to ensuring that. Only two weeks ago they supported the deal, and the US supported the deal this week. Discussions will continue with the Americans and other allies, but as I said, the priority is our base and our national security.”