MI5 Chief Warns of Escalating Hybrid Threats from Iran and Russia in Europe

Key points

• MI5 chief Ken McCallum stated that threats have shifted from state-owned assets to people, businesses, and communities, marking a 'new era' of national security.
• Iran has conducted over 50 arrests in the UK in the past year, linked to arson, sabotage, and plots against military sites like RAF Fairford.
• Russia is described as 'aggressor number one,' using tactics that stay just below the NATO Article 5 threshold, including drone attacks and sabotage of defense industries.
• McCallum warned that AI could 'change the stakes' for bioweapons, prompting MI5 to create a new threat center focused on AI-driven security risks.
• The US-Iran war, nearing eight months, has intensified Iranian hybrid campaigns in Europe, targeting Jewish communities and military infrastructure.

Background

This briefing follows a series of escalating hybrid warfare incidents in Europe, including the Leipzig drone attack in August 2026 and subsequent EU sanctions against Russia. Earlier in 2026, Ukrainian officials urged Europe to leverage their experience in countering Russian hybrid tactics, while NATO leaders warned against escalation. The current MI5 assessment builds on these prior warnings, highlighting a shift in the nature and intensity of threats from both Moscow and Tehran.

How outlets are covering it

CBS News and The Washington Post emphasize the shift in Iranian tactics toward 'harder targets' like military bases, citing the RAF Fairford plot as a key example. The Guardian focuses on the AI-bioweapons angle, detailing how AI tools could lower the barrier for creating pathogens, a concern McCallum raised in his speech. AP News highlights the broader context of the US-Iran war and the limited capabilities of Iran outside the Middle East. All sources agree on the rising threat level but differ in emphasis: CBS and WaPo focus on the physical attacks, while The Guardian focuses on the technological risks.

Why it matters

The escalation in hybrid attacks by Iran and Russia signals a new phase of conflict in Europe, where traditional military boundaries are blurred. The potential for AI to accelerate bioweapons development adds a new dimension to the threat, requiring updated security protocols and international cooperation. The targeting of Jewish communities and military sites underscores the direct impact of geopolitical conflicts on European security and public safety.

What to watch

MI5 will likely increase surveillance and counterterrorism operations in response to the shifting threats. European nations may further coordinate on sanctions and defense against Russian hybrid tactics. The new MI5 threat center will focus on mitigating AI-driven risks, potentially influencing global AI safety policies. Continued monitoring of Iranian and Russian activities in Europe is expected, with possible further arrests and investigations.