MI5 is devoting more resources to countering state threats than it did during the Cold War, its head, Sir Ken McCallum, said in an annual speech at the service’s London headquarters. He described Russia as “aggressor number one” and said threats from foreign adversaries had quadrupled. The state’s security apparatus, he said, now handles terrorism and state-threat missions on “pretty much of equal scale.”
The security apparatus expands
McCallum set out the scale of MI5’s work against foreign governments and violent groups. The service has identified and expelled Russian spies from the UK, leaving the Kremlin reliant on paid proxies for attempted attacks. “With its traditional covert footprint eviscerated by almost 1,000 expulsions since the invasion, the Kremlin’s global toolkit is weak. So we see them scrambling to pay criminals to do their bidding,” he said. “These aren't the actions of a great power with the strategic upper hand.”
He said Russia was waging hybrid warfare while avoiding a joint response from Nato, and described the Kremlin as testing how far it could go without crossing what he called a “foolish” line. Russia had stopped short of “conventional conflict” with the military alliance and was trying to unsettle European countries, he said. Its progress in the full-scale invasion of Ukraine had been “minimal and horrifically costly,” in McCallum’s words.
Iran, he said, was also expanding a hybrid campaign in the UK. Authorities made fifty arrests in the last year over Iran-linked activities. McCallum said much of the aggression had targeted Jewish communities, as well as “harder targets, like military sites.” The National Security Act, a 2023 law designed to target people working against UK interests for foreign powers, has seen heavy use against threats from China, Iran and Russia.
Threats named, powers mobilised
McCallum also warned about extreme right-wing terrorism and violent groups’ use of new technology. “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. His greatest concern, he told Thames House, was extremist groups using AI to make bioweapons. The threat “isn't yet realised,” but the technology had the “potential to change the stakes on existing or even new bioweapons.”
He said the UK Intelligence Community - MIS, GCHQ, M16 - works closely with the UK’s globally respected AI Security Institute. The warning described a state response organised through intelligence agencies and a security institute, while, by McCallum’s account, the possible threat remains unrealised.
In April, the UK raised its terrorism threat level to severe for the first time in five years, meaning an attack was highly likely. McCallum said Islamist groups such as Al Qaeda and so-called Islamic State continued to direct and inspire attacks. He said the increased risk was also driven “in significant part” by extreme right-wing terrorism.
A warning aimed at the young
“Over the last year the most marked trend has been an increase in cases where extremist versions of anti-immigration and anti-Muslim grievance are tipping into terrorist intent,” McCallum said. He described extreme right-wing terrorism as tending to “skew young” and being driven by the internet.
MI5 had recently investigated a “radicalised extreme right-wing 13-year-old here in the UK,” he said. McCallum added that the investigation generated insight that enabled one of MI5’s international partners to prevent a lethal attack on their soil. His speech placed anti-immigration and anti-Muslim grievance among the factors under investigation, alongside foreign state activity and risks posed by technology. The response he outlined was the expansion and coordination of intelligence work across national and international lines.