Iran seeks harder targets, MI5 warns
Ken McCallum, director general of MI5, gave his annual threat speech on 13 October 2026. He said Tehran is trying to intensify attacks in Britain beyond its traditional targets, Iranians opposed to the Islamic Republic's authorities. He described Iranian ambitions to hit harder targets, such as military sites, as a notable shift this year. Britain says Iranian proxies carried out arson and sabotage attacks on Jewish sites. McCallum said more than 50 people have been arrested over Iran-linked plots in the past year.
The suspected plot at RAF Fairford
On 27 September, scores of residents were evacuated from homes near RAF Fairford, the western English base used by the US Air Force, as armed officers and army explosives experts moved into the rural area. The Guardian reported that five men from London had been seen in three white vans in a village beside the base shortly after midnight. Police later said they found a quantity of gasoline, an accelerant, in three vans at the site, but no explosives. Two more suspects were arrested later. All seven men, in their 20s, were released on bail under investigation, suspected of preparing a terrorist act, and none has been charged.
- Five men seen in three vans near RAF Fairford shortly after midnight; scores of residents evacuated
- Two more suspects arrested; all seven later released on bail under investigation
- Burnham says the IRGC almost certainly directed the plot
- McCallum's annual speech warns Iran is seeking harder targets such as military sites
On Monday, 12 October, Prime Minister Andy Burnham said the plot was "almost certainly" directed by Iran's Revolutionary Guard, the IRGC. Iran denies involvement but has said it considers any base used to attack its territory a legitimate target. Tehran summoned British Ambassador Hugo Shorter and warned it could "seriously reconsider" relations unless London supplies evidence. The US pulled about a dozen long-range bombers from the base after the incident. McCallum said he could not discuss the Fairford case while the investigation continues, but called it "not unique", citing examples elsewhere in Britain and around the world.
Iran's Foreign Ministry responded:
The British government must provide documents and evidence supporting its accusations against Iran.
Sanctions and a joint response
On 13 October, the Foreign Office summoned Iran's ambassador in London and said the UK would not tolerate threats on its soil. Sanctions were announced against two Iranian nationals. Ruhollah Bazghandi is described as head of counter-intelligence operations at the IRGC. Shahram Ali Reza Tamarzadeh Jakki was sanctioned over activities for the Iranian regime involving plans for attacks abroad, and is considered a key facilitator for the Zindashti network, a criminal group led by Naji Sharifi Zindashti that works with Iranian intelligence. Both men have had their assets frozen, face a travel ban to the UK and are barred from running companies there. About thirty countries, including Spain, France, Germany and the United States, issued a joint statement backing the accusation against Iran.
Russia, AI and terrorism
McCallum called Russia "aggressor number one" and said Moscow is escalating hybrid warfare while staying below the threshold for a direct NATO response. He said the expulsion of Russian officials from embassies since the 2022 invasion of Ukraine has pushed Moscow to rely on volunteers and criminal proxies. He added that state threats had quadrupled over the last decade. On AI, he said it is supercharging the cybersecurity contest, and that MI5 has caught potential attackers using it to refine reconnaissance and attack methods. His greatest concern is terrorists developing bioweapons or new pathogens, which, as far as he knows, has not yet happened.
Put at its simplest, human history has given us no experience of facing an actor which is smarter than we are, is capable of out-thinking us.
Britain raised its national terrorism threat level to "severe" in April, meaning an attack within six months is highly likely. McCallum said Al Qaeda and Islamic State continue to inspire plots, and he pointed to a marked rise in cases where extreme anti-immigration and anti-Muslim grievances tip into terrorist intent.
There is no law of physics dictating that rising state threats will be accompanied by diminishing terrorist threats.