Lord Hermer KC, the UK attorney general, advised the government that the US-Israeli military campaign against Iran does not accord with international law 1. That assessment shaped Prime Minister Starmer's initial refusal on 28 February to grant Washington access to any British military facilities 2. Starmer reversed within 48 hours, authorising "specific and limited defensive operations" from RAF Fairford and Diego Garcia while refusing RAF Akrotiri in Cyprus for offensive strikes. A former Director of Public Prosecutions now facilitates operations his own chief law officer assessed as unlawful.
Chatham House published analysis arguing the distinction between defensive and offensive base use "blur[s] the line between lawful self-defence and unlawful war on Iran" 3. Under Article 16 of the International Law Commission's Articles on State Responsibility, a state that knowingly aids another's internationally wrongful act bears international responsibility — regardless of how it categorises its contribution. The label "defensive" does not insulate London if the underlying campaign is assessed as unlawful.
The UK faced a version of this in 2003. Attorney General Lord Goldsmith's advice on the Iraq invasion — initially equivocal, later firmed up under political pressure — consumed the Chilcot Inquiry for seven years and destroyed the Blair government's credibility on the use of force. Starmer's legal exposure is sharper: Goldsmith's advice was ambiguous; Hermer's, as reported by Middle East Eye, is not 4.
Iran had warned the UK on Thursday that permitting US access to British bases made Britain "a participant in aggression." Within hours of London confirming that access, two intermediate-range ballistic missiles were fired at Diego Garcia — the first Iranian weapons aimed at British sovereign territory in this conflict. One malfunctioned; the other was intercepted; no damage resulted. Britain is now the only European state absorbing direct Iranian retaliatory fire, while the Coalition of Hormuz-statement signatories has grown from seven to 22 without a single warship deployment.
