The UK’s domestic intelligence chief has issued a stark warning: the nation faces an escalating and diverse array of threats from hostile states like Russia, Iran, and China, alongside an ever-present and “huge” risk of terrorism. Speaking on October 16, 2025, MI5 Director General Ken McCallum highlighted a concerning 35% surge in investigations into state-sponsored threats. He noted that these adversarial nations are increasingly resorting to “ugly” tactics typically associated with terrorist groups.
McCallum revealed that MI5 has successfully thwarted numerous surveillance operations orchestrated by Russia and has identified over 20 potentially deadly plots linked to Iran. During his annual address at MI5’s London headquarters, he emphasized, “In 2025, MI5 is grappling with a greater volume and wider variety of threats from both terrorists and state actors than I have ever witnessed.”
While the UK has consistently accused Russia, Iran, and China of hostile activities, these nations have routinely denied the allegations. Earlier this year, for instance, six individuals from Bulgaria were incarcerated for conducting surveillance on behalf of Russia, while five others were convicted for an arson attack in London on Ukrainian-linked businesses, an act British officials attributed to Russia’s Wagner mercenary group.
“Alongside our European partners, MI5 remains relentless in identifying those who follow orders from Russian operatives,” McCallum affirmed. “And we will continue to trace these trails back to those commanding these operations, who mistakenly believe they are anonymous and untraceable behind their screens. They are not.”
He further pointed to China’s involvement in cyber espionage, its efforts to entice academics to China, covert interference in British public life, and the harassment of pro-democracy activists within the UK. Regarding Iran, McCallum stated that Tehran is “frantically” attempting to silence its critics globally, referencing recent disclosures by Australia of Iranian involvement in antisemitic plots and Dutch authorities’ revelation of a thwarted assassination attempt.
McCallum underscored the “huge” and persistent terrorist threat to Britain, noting that MI5 and police forces have collectively foiled 19 advanced attack plots since early 2020. He warned that groups like Al Qaeda and Islamic State are re-emerging with renewed ambition, leveraging global instability to strengthen their positions.