US Military Sites Still at Risk After Foiled Plot, Ex-Terror Chief Says - Newsweek

A suspected terrorist plot that was foiled at a U.S.-operated military base highlights the heightened risk that American facilities in the U.K. face due to the Iran war, a former British terrorism chief has told Newsweek.

Counterterrorism detectives are investigating a possible plot linked to Iran following the arrest of five men near RAF Fairford, near Whelford, Gloucestershire, on Sunday.

The site has been used by American bombers for decades, including during the war that Trump launched on the Islamic Republic on February 28.

Investigators have not concluded if it is a state-backed attack linked to Iran, but the Islamic Republic had targeted U.S. military sites in the Middle East. Meanwhile, reports in August suggested U.S. facilities in Europe could also be in Tehran's crosshairs.

Chris Phillips, former head of the U.K's National Counter Terrorism Security Office, told Newsweek on Monday that with the U.K already at a severe threat of terrorism partly due to the Iran war, the risk posed to U.S. facilities in the country has "always been high."

"The threat is real. It's not going to go away and, even when the war is finished in Iran, that doesn't mean to say it all just fades into obscurity."

"What worries me is there's still a bomb factory out there; clearly, they made some explosives," he added.

When contacted for comment about the threat American bases may face in the U.K., a U.S. Defense Department spokesperson told Newsweek: "U.S. European Command (US ECOM) remains vigilant and will take appropriate actions to ensure the safety and security of our U.S. service members, civilians, contractors, and their families across the European theater."

On Monday, Gloucestershire police were questioning the five men arrested who have not been named. Initially arrested over suspected explosives offenses and then on suspicion of preparing an act of terrorism, they can be held for up to 14 days without charge.

The Times newspaper in the U.K. cited counterterrorism sources that the suspects were U.K. nationals in their 20s, living in the London suburbs of Camden, Westminster and Willesden, although this has not been confirmed.

British intelligence had previously said that Iran, as well as Russia, have used proxies to commit acts on British soil. Officials warned in March how cases involving activity by hostile states including Iran had increased by 50 percent in the six months to December 2025 and warned Tehran could expand its targets in the U.K.

Phillips, founder of the consultancy IPPSO (International Protect and Prepare Security Office), said a key aspect of the case, if Iran is behind it, is to find out whether it was directed by the government in Tehran "or is it inspired by actions that are happening over there? Either of those two could be true."

However, Phillips doubted President Donald Trump's comments on Sunday that the suspects had been detained following cooperation between the U.S. and the U.K. and had been tracked for some time.

"It's not impossible that they were under surveillance to some degree, but clearly British police would never allow them to put a bomb together and then take it to the site. They would have been arrested prior to that," said Phillips.

"I think it's unlikely they were under tight surveillance. I think it's clear that everyone down at Fairford knew that there was a real threat," he added.

Residents reported that security had increased around the perimeter of the site days before, with extra concrete barriers and large trucks blocking the entrance. But it appears the arrests were made after a tipoff from a farmer who had noticed a large group of hooded and masked men.

The unnamed farmer told the BBC that the group ran ahead of her when they saw her, with some fleeing into a field and others toward a neighboring village. She said her 999 call "foiled whatever plans they had."

Gloucestershire police said it got its first report of three suspicious vehicles near the base at around 12.45 a.m. Sunday. Around 85 homes have been evacuated as the investigation continues.

"They don't sound very professional to be honest," said Phillips, "If you have got a bomb, why don't you just drive the vehicles? If you're going to do it, you might as well just drive them off and attack something.

"Instead of that, they ran into the woods, taking their balaclavas off," he said, although while they were, "not high-quality terrorists…anyone that makes a bomb is a dangerous person."

"The great news is that a farmer coming home has managed to bump into this motley crew," he added.

RAF Fairford is near Swindon in Gloucestershire, 100 miles west of London, and is the headquarters for the U.S. 501st Combat Support Wing and the 420th Air Base Squadron.

The U.K. did not join the U.S.-Israeli war on Iran that started on February 28 and had denied Trump’s request to use bases in the U.K. but in March, the then-Prime Minister Keir Starmer let the U.S. utilize British bases for "defensive" operations against Iran’s missiles.

American B-1 and B-52 bombers have taken off from RAF Fairford for operations during the Iran conflict.

The U.S. also has a military presence at other U.K. bases, including RAF facilities that support the U.S. Air Force.

On Monday, the U.S. Department of Defense raised its threat level to RAF Lakenheath, which hosts the 48th Fighter Wing operating F-15 and F-35 jets, and Mildenhall in Suffolk, a base for U.S. air refueling tankers, according to crisis-monitoring website Monitor the Situation and local media outlets.

The U.S. Defense Department did not confirm the measures, telling Newsweek in a statement, "for operational security reasons, we will not discuss specific force protection measures."

"We are working closely with our U.K. counterparts to monitor this situation, minimize impacts and ensure the safety of U.S. personnel, their families, and the local community," the statement added.