MI5 Chief Says State Threats Have Quadrupled as Russia, Iran and AI Pose Growing Danger to UK

The head of Britain's domestic intelligence service has disclosed that MI5 is now allocating more resources to countering state threats than at any point during the Cold War, describing a dramatic shift in the security landscape facing the United Kingdom.

In his annual address delivered at MI5's headquarters in central London, Sir Ken McCallum said threats emanating from foreign adversaries had quadrupled over the past decade. He identified Russia as "aggressor number one," while also highlighting an expanding campaign of Iran-linked aggression directed at Jewish sites and military installations across the country.

The speech, delivered at Thames House, painted a picture of an intelligence agency whose workload has been fundamentally reshaped by the convergence of hostile state activity, terrorism, and rapid technological change. Sir Ken noted that counterterrorism work and efforts to counter state threats are now "pretty much of equal scale" — a situation he characterised as a "huge shift" in recent years.

On Russia, the MI5 chief said Moscow has deliberately avoided "conventional conflict" with Nato, instead pursuing a strategy of hybrid warfare aimed at unsettling European nations. He pointed out that Russia's progress in its full-scale invasion of Ukraine has been "minimal and horrifically costly," suggesting that the Kremlin's military ambitions have not translated into strategic gains.

Hybrid warfare, a term used to describe non-military tactics such as cyber-attacks, sabotage, and disinformation campaigns, has become a central pillar of Russian strategy, according to the intelligence assessment. Such operations are frequently carried out through proxies, with Moscow consistently denying involvement despite mounting evidence to the contrary.

Sir Ken revealed that MI5's success in identifying and expelling Russian operatives has significantly degraded the Kremlin's ability to conduct covert operations on British soil. Since the invasion of Ukraine, nearly 1,000 expulsions have "eviscerated" Russia's traditional covert footprint, leaving its global toolkit weakened.

"So we see them scrambling to pay criminals to do their bidding," he said, adding that such behaviour demonstrates "not the actions of a great power with the strategic upper hand."

His remarks come amid growing concern across Europe, where an increasing number of leaders have warned that Russia may be preparing attacks designed to test their commitment to supporting Ukraine. The MI5 chief's assessment appears to reinforce those anxieties, suggesting that Moscow's capacity for disruption remains significant even as its traditional spy networks have been dismantled.

Asked about recent comments from Prime Minister Andy Burnham regarding Russian interference in the Brexit referendum, Sir Ken said it was "not new news" that Moscow had attempted to exert influence. However, he drew a careful distinction between "interference attempted" and "outcome achieved," stressing that the result of the 2016 referendum was "not in dispute."

He acknowledged that Russian media outlets, along with "so-called internet trolls and bot farms," had sought to influence the Brexit debate — a matter he said was already on the public record. Nevertheless, he expressed concern about the ongoing discussion surrounding Russian interference, warning that overstating the effectiveness of such operations could inadvertently benefit adversaries.

"I am a little bit anxious that we don't play into our adversaries' hands by making these trolls look 10ft tall," he told reporters following his speech.

Turning to Iran, Sir Ken warned that Tehran is expanding its own hybrid campaign within the UK, with 50 arrests linked to Iranian activity over the past year alone. Much of this aggression has been directed at Jewish communities, he said, as well as at "harder targets, like military sites."

While he did not directly reference arrests at RAF Fairford during his formal address, he told reporters afterwards that the incident was "not unique," adding: "We have seen Iranian interest beyond RAF Fairford in the UK." The airbase in Gloucestershire was the scene of an incident involving three suspicious vans parked nearby, which led to seven people being arrested and bailed by counter-terrorism police.

Prime Minister Burnham has previously stated that the incident was "almost certainly directed by Iran's Islamic Revolutionary Guard." Sir Ken struck a defiant tone, declaring that "those who seek to cause mayhem on British streets — whether hired thugs here or their paymasters overseas — will meet an unflinching response."

The MI5 chief also noted that the National Security Act, a 2023 law designed to target individuals working against UK interests on behalf of foreign powers, is in heavy use. The legislation has been employed to address threats from China, Iran, and Russia alike, reflecting what appears to be a broadening of the UK's counter-state-threat framework.

A significant portion of Sir Ken's address focused on the emerging challenges posed by artificial intelligence. He warned that AI is "supercharging the cyber-security contest between attackers and defenders," enabling extremist groups to produce propaganda and radicalising material tailored to individual targets.

"We've caught terrorists seeking to exploit AI to improve their reconnaissance and attack methodologies, with AI-enabled drones adding a new twist," he said. He further warned that the threat of AI being used to develop bioweapons, while "not yet realised," has the "potential to change the stakes" in ways that could fundamentally alter national security calculations.

"These risks are real," Sir Ken emphasised, noting that MI5, GCHQ, and MI6 are working closely with the UK's AI Security Institute to address them. He described the challenge in stark terms, telling his audience: "Put at its simplest, human history has given us no experience of facing an actor which is smarter than we are."

To help meet this challenge, Sir Ken announced the creation of an AI Threat Assessment Centre, which he said would evaluate intelligence sources and "separate the bluster from the realities." The new unit represents a recognition that understanding AI-related threats requires dedicated expertise and sustained attention.

The MI5 chief also referenced the raising of the UK's terrorism threat level to "severe" in April — the first such increase in five years — meaning an attack is considered highly likely. He noted that Islamist groups such as Al Qaeda continue to feature in the threat picture, alongside extreme right-wing terrorism, which he identified as a rising concern.

The speech underscored the complex and overlapping nature of the threats Britain now faces, with hostile states, terrorist organisations, and emerging technologies all contributing to what Sir Ken described as a security environment without historical precedent.