MI5 chief warns Iran is targeting British military sites and RAF Fairford terror plot is 'not unique'

Sir Ken McCallum delivered his annual threat assessment at Thames House on Tuesday, revealing that Iran has sharply widened its targets in Britain, shifting from attacks on Iranian dissidents to operations against military installations. Over the past year, arrests in Iran-linked cases have exceeded 50, among them suspects tied to alleged arson attacks on Jewish sites in London and a suspected synagogue plot in Manchester. McCallum also unveiled a new AI Threat Assessment Centre, cautioning that artificial intelligence could raise the stakes around bioweapons and is already helping terrorists refine their attack planning. Iran's foreign ministry summoned Britain's ambassador Hugo Shorter to press for evidence connecting Tehran to the RAF Fairford plot.

MI5 is now putting more resource into countering state threats than at any point during the Cold War, with its state threats caseload having quadrupled in a decade.

British businesses have been told to prepare for power cuts, internet failures and supply chain collapse as hostile states escalate sabotage, arson and cyber attacks on critical infrastructure.