Allied Intelligence — 2026-10-14

MI5 Chief McCallum Says Service Devotes More Resources to Russian Threat Than During Cold War and Launches AI Threat Assessment Centre

BLUFMI5's pivot to criminal-proxy threats and its elevation of Protect as a core mission signal that Russian and Iranian hybrid operations against UK civilian and military targets will intensify before traditional espionage networks can reconstitute.

MI5 Director General Ken McCallum said in his annual Thames House speech on Tuesday that Russia remains "aggressor number one" and that MI5 devotes more resources to state threats than during the Cold War, with state threats having quadrupled over the last decade 123. He said Russia is escalating hybrid warfare below the NATO Article 5 threshold, citing about 1,000 expulsions since 2022 and a turn to paid criminal proxies 24. Reuters reported McCallum saying Iran-linked operations produced more than 50 UK arrests in the past year, with Iranian ambitions shifting toward "harder targets, like military sites" 34. Euronews reported that Prime Minister Andy Burnham told parliament on Monday the RAF Fairford incident was "almost certainly directed" by the IRGC; McCallum declined to discuss it, and Tehran denies involvement 23. McCallum also said MI5 has caught terrorists using AI for reconnaissance, and that AI-assisted bioweapons development is his greatest concern, though not yet realized 34.

Analysis
Russia's hybrid campaign now runs on paid criminal proxies because MI5 and its partners have stripped the Kremlin of its traditional covert footprint. That pushes the threat toward arson, sabotage and cyber disruption of civilian targets, which explains why MI5 made Protect a third core mission. Iran is applying the same proxy model to military sites, and McCallum's remark that Fairford is "not unique" signals more such cases. His limited estimate of Iranian proxy capability in the UK, set against the IRGC's deeper experience abroad, is the main variable to watch. Confidence is high, based on consistent reporting across seven outlets, including CNN's primary account of the speech. The Fairford attribution rests on the Prime Minister's statement and an ongoing investigation. The Cold War comparison may instead measure budget allocation more than any rise in damaging attacks, and it serves MI5's case for resources and legislative backing.

7 sources

MI5 devoting more resources to Russian threat than during Cold War, spy chief warns - National Security News
Russia remains 'aggressor number one,' UK's MI5 spy agency chief warns in threat update - Euronews
Iran, Russia ramping up hybrid campaigns in Britain, MI5 Director-General Ken McCallum says - The Jerusalem Post
Factbox-MI5 chief lists Iran, Russia, AI and terrorists among threats to UK - Reuters (via 93.3 The Drive)
MI5 Chief Warns Hostile State Threats Higher Than Cold War - Bloomberg
MI5 chief warns of AI 'supercharging' threats posed by hostile actors like Russia and Iran - CNN
MI5 chief warns Russia is UK's 'aggressor number one' as Iran and AI threats grow - WION