MI5 Director General Ken McCallum warned Britons they must build resilience against “escalating” Russian hybrid warfare, as the security service devotes more resources to hostile state threats than during the Cold War. Speaking at Thames House in London, he called for greater “systemic resilience” in critical infrastructure, banking and defence, alongside stronger “societal resilience” against polarised online debate and radicalisation.
“Russia remains aggressor No. 1,” McCallum said, describing Kremlin tactics that fall short of conventional conflict. He warned that interconnected financial systems, energy grids, supply chains and manufacturing bases are key vulnerabilities. MI5’s state threats caseload has “quadrupled” over the past decade, and in 2026 the service will devote more resources to countering state threats than at any point during the Cold War.
McCallum cautioned against letting Moscow’s strategy intimidate Britain, warning that exaggerating Russian interference would “do our adversaries’ work for them.” He also addressed recent security incidents, noting Iran-linked operations have led to more than 50 arrests in the UK over the last 12 months. He highlighted the establishment of an AI Threat Assessment Centre, warning of AI’s potential to enable hostile actors to create novel pathogens.
Source: Bloomberg Markets · Summarized by HeadlinesBriefing