A reported US plan to stage potential military operations against Iran using facilities on British territory has hit a legal and diplomatic roadblock after the UK declined to pre-authorize use of its bases without further review.
According to the reporting, detailed White House contingency plans under development envision operations involving Diego Garcia in the Indian Ocean and RAF Fairford in Gloucestershire - the latter known to host America's European fleet of heavy bombers. Current bilateral arrangements between the UK and the US require that any military action launched from those bases have prior approval from the UK government.
British officials have not granted permission for the bases to be used for any potential strike on Iran, the reporting says, pointing to concerns that participation could run afoul of international law. The legal issue cited is the proposition that international law does not distinguish between a state that carries out an internationally wrongful act and a state that provides support for that act if the supporting state has knowledge of the circumstances surrounding it.
The sequence of diplomatic moves described in the report links this refusal to a shift in US posture on a separate matter. President Trump reportedly withdrew his support for an agreement to transfer the Chagos Islands to Mauritius after the UK resisted pre-clearing US use of the military bases.
Further context on domestic oversight of base usage was noted with reference to 2021 parliamentary exchanges. At that time, John Healey - now serving as defense secretary - sought clarification in Parliament about the rules that apply when US forces propose to use British bases. He was informed that any proposed operation would need to adhere to UK law and to Britain’s interpretation of the relevant rules of international law.
The sequence outlined in the reporting highlights three interlinked constraints: bilateral base-use agreements requiring UK approval, the UK’s assessment of international legal exposure for supporting third-party military action, and the diplomatic consequences that flow from withheld approvals. The reporting also records a direct conversation between President Trump and Prime Minister Starmer the night before the public reversal on the Chagos transfer, tied to the ultimatum delivered to Iran.
Contextual note - The material presented here follows the details reported about interactions between the US and UK on base use and the related diplomatic developments. Where the reporting linked specific conversations and decisions, those elements are reflected above without additional inference.