British Prime Minister Keir Starmer has responded firmly to criticism from U.S. President Donald Trump regarding the United Kingdom’s refusal to participate in military action against Iran.

Although the UK and the United States share a long-standing military alliance, Starmer defended his government’s decision, stressing that his foremost responsibility is to act in Britain’s national interest. He maintained that his stance was carefully considered and remains unchanged. Addressing the possibility of deploying British troops, the Prime Minister made it clear that he would not authorise the involvement of UK forces in any operation that could be deemed unlawful. He added that British service personnel deserve clarity, legality, and proper justification before being committed to combat operations.

Analysts suggest that the UK government is deliberately underscoring its commitment to international law in the face of mounting geopolitical tensions.

President Trump had earlier voiced disappointment after reports emerged that Britain initially declined to permit the U.S. to use certain UK military bases for potential strikes on Iran. In an interview, Trump expressed surprise at the decision, suggesting it was unprecedented in the history of cooperation between the two nations and implying that legal concerns influenced Starmer’s position.

Reports indicate that Washington had been considering operational plans involving joint US-UK military facilities, including the Diego Garcia base in the Chagos Archipelago and RAF Fairford in Gloucestershire, a strategic location for America’s heavy bombers in Europe. However, under existing defence agreements, U.S. forces require explicit approval from London before launching operations from British territory.

Sources suggest that the British government’s hesitation is largely driven by concerns about compliance with international law, particularly the risk of being implicated in actions that might later be ruled unlawful.