Espionage, cyberwar and terror plots: MI5 warns UK facing record surge in threats from Russia, China, Iran

MI5 Director General Ken McCallum - File Photo

Britain is facing a surge in security threats from hostile states including Russia, Iran and China, even as the danger from terrorism remains “huge,” according to the country’s domestic intelligence chief.

MI5 Director General Ken McCallum said on Thursday that the agency is now dealing with more diverse and complex threats than ever before, with state-backed espionage and terror-linked activities both on the rise. “In 2025, MI5 is contending with more volume and more variety of threats from terrorists and state actors than I’ve ever seen,” McCallum said during his annual address at MI5 headquarters in London.

McCallum revealed that investigations into state-backed threats had jumped by 35 per cent, and that hostile nations were increasingly using “ugly” tactics once associated primarily with extremist groups. He said MI5 had disrupted “a stream of surveillance plots with hostile intent” tied to Russia and uncovered over 20 Iran-backed operations that “could have proven deadly.”

The MI5 chief accused Moscow, Tehran and Beijing of continuing to undermine the UK’s national security through espionage, cyberattacks and intimidation campaigns. He said Russian networks remain active despite several recent exposures. Earlier this year, six Bulgarians were jailed for spying for Russia, while five men were convicted for setting fire to Ukraine-linked businesses in London, an attack British officials believe was ordered by Russia’s Wagner mercenary group.

“With our partners across Europe, MI5 will keep detecting those who take orders from Russian thugs,” McCallum said. “And we will keep following the trails back to those giving the orders, who imagine they’re anonymous and unfindable behind their screens. They’re not.”

Turning to China, McCallum accused Beijing of orchestrating widespread cyber espionage, cultivating foreign academics for intelligence purposes, and covertly influencing public life in the UK. He said Chinese authorities have also been involved in the harassment of pro-democracy activists who have sought refuge in Britain.

On Iran, he described a pattern of increasingly desperate behaviour. “Tehran is frantically trying to silence its critics around the world,” McCallum warned, noting that Iranian agents have been implicated in antisemitic plots in Australia and an attempted assassination in the Netherlands.

The MI5 chief said the terrorism threat to the UK has not diminished despite the focus on state-sponsored espionage. He revealed that MI5 and British police had disrupted 19 late-stage attack plots since 2020. “Al Qaeda and Islamic State are once again becoming more ambitious, taking advantage of instability overseas to gain firmer footholds,” McCallum said.

The warning reflects an increasingly crowded threat landscape, where Britain finds itself defending against both traditional espionage and modern hybrid warfare, while still confronting the persistent menace of global jihadist groups.