Britain’s Attorney General, Richard Hermer, has cautioned that any UK involvement in strikes against Iran, beyond purely defensive measures, may be illegal under international law. His warning arises amid growing pressure on Prime Minister Keir Starmer to support U.S. or Israeli military action, particularly concerning a potential attack on Iran’s underground Fordow nuclear facility. Sending aircraft from Diego Garcia or Cyprus, or otherwise enabling or participating in offensive operations, could place the UK in violation of international law, he argued.
Hermer reportedly advised that international law recognizes force only under limited conditions: to defend oneself or an ally, or when explicitly authorized by the UN Security Council. Since no such authorisation exists, and Iran is not deemed to pose an “imminent threat,”, offensive action would be legally questionable. Ministers are now under fire from opposition politicians, including Liberal Democrat leader Ed Davey and Labour’s Emily Thornberry, who are demanding that the government publicly release this legal advice. They warn that without clarity, the UK risks becoming embroiled in an illegal war.
Prime Minister Starmer has adopted a cautious tone, emphasizing the importance of de-escalation and diplomacy. While he acknowledges concerns over Iran’s nuclear ambitions and affirms Israel’s right to self-defense, he stresses that conflict should be avoided where possible. Concurrently, Foreign Secretary David Lammy is pressing counterparts in Washington to return to negotiations and postpone any military options.
This legal dilemma carries real-world consequences. The U.S. has reportedly sought permission to use British bases such as Diego Garcia and RAF Akrotiri to launch attacks. Whitehall officials, citing Hermer’s legal opinion, have declined, arguing that facilitating a pre-emptive strike without UN backing would breach international law.
Domestically, ministers are acutely aware of the political and moral ramifications of pursuing military action without proper legal grounding. Historically, when conflicts like the Iraq War were later revealed as legally dubious, public trust and government credibility suffered. The Attorney General’s intervention aims to guide ministers toward legally sound decisions, preventing hasty escalation.
For now, Starmer’s government remains on edge. With tensions rising between Israel and Iran and U.S. pressure increasing, the UK finds itself at a crossroads: to support allies in a potentially unlawful military campaign, or to uphold international legal standards and steer toward diplomacy.
