MI5 director general Ken McCallum has warned that Britain faces a profound transformation in national security threats, comparing the scale of change to the aftermath of the September 11 attacks. In his annual assessment, he identified Russia as Britain’s foremost state threat, alongside growing concerns about Iranian operations, terrorism, cyberattacks and sabotage. He warned that hostile actors increasingly seek to undermine critical infrastructure, disrupt communities and spread division through manipulative online content. Artificial intelligence presents additional dangers, potentially enabling sophisticated cyberattacks, terrorist reconnaissance, drone operations and even biological weapons development. McCallum said the security service is strengthening national resilience through its new 'Protect' mission, focusing on infrastructure, technology and community cohesion. He also highlighted violence targeting politicians and religious communities, including the killing of Ann Widdecombe. He warned that the present period of heightened insecurity could continue for years, requiring vigilance and cooperation across British society.