American warplanes have been relocated after reported threats, U.S. military families are being urged to take extra security precautions outside base gates, and allies across Europe are bolstering air defenses.
The situation points to an evolving range of threats confronting U.S. forces in a region that also serves as a major staging ground for American operations in the Middle East.
Security has become an increasingly complex proposition on the Continent, where suspected Iran-backed terrorist plots, Russian sabotage operations and cyberattacks are testing how governments and military commanders protect personnel and installations.
The dangers have been especially visible in the United Kingdom. On Monday, numerous U.S. aircraft departed RAF Mildenhall, including refueling tankers, following reports of a potential threat from Iran.
Mildenhall and nearby RAF Lakenheath were placed under Force Protection Condition Charlie, the second-highest security alert level, in response to the threat, according to multiple media reports.
A U.S. airman patrols RAF Fairford, England, Nov. 20, 2025. U.S. and allied moved aircraft out of British bases because of threats of attack, and military families in Europe are being urged to stay alert off base. (Adam Enbal/U.S. Air Force)
Military officials have declined to discuss details of the situation in the U.K., citing operational security.
But after the aircraft were transferred, U.S. European Command said it is “taking coordinated and appropriate actions” to ensure the safety and security of service members, civilians, contractors and families.
The latest incident follows other abrupt U.S. military moves amid a flurry of Iranian threats. It comes as President Donald Trump weighs whether to resume major military operations against Iran.
In October, 12 B-1 bombers also were removed from RAF Fairford after British authorities uncovered a suspected Iran-backed plot against the installation.
The Justice Department on Tuesday announced charges against three men accused of participating in a terrorist network that prosecutors say was behind the plot against RAF Fairford.
Federal prosecutors say Mohammad Dawood al-Saadi, a dual citizen of Iran and Iraq, orchestrated the intended attack on the base from a jail cell in New York. He is awaiting trial on pending terrorism charges.
The other two people indicted in the plot are Mohsen Mohajeri and Mohammad Ali al-Hassani. They were in Iran at the time of the RAF Fairford plot and relied on a network of contacts in the U.K., according to a Justice Department statement.
Iran’s national security chief, Mohsen Rezaei, said Wednesday that military bases in Europe could become targets in the event of renewed U.S. attacks.
“If American aircraft take off from an American military base, even one located in a European country or some other distant region, to bomb Iran, we will strike those bases as well,” Rezaei said on Lebanese television.
French Master Sgt. Frederic Keiffer scans an ID card at a gate at Ramstein Air Base, Germany, Sept. 8, 2021. Security has been tightened at U.S. bases in Europe, where an initiative known as “See Something, Do Something” was recently launched. (Jacob Wongwai/U.S. Air Force)
Earlier this month, EUCOM launched a theaterwide security awareness campaign urging troops, civilian employees and military families to vary their commuting routes and limit the personal information they share online.
Known as “See Something, Do Something,” the initiative also calls for vigilance in crowded public places. EUCOM has not linked the campaign to any specific threat.
But Gen. Alexus Grynkewich, who leads EUCOM and serves as NATO’s top military commander, said the effort is intended to strengthen the collective security of military communities.
“Maintaining our strategic advantage requires a daily partnership with our military and local communities,” Grynkewich said.
The current security situation extends beyond concerns linked to Iran. Across Europe, governments have accused Russia of an expanding campaign of espionage and sabotage aimed at countries supporting Ukraine.
In Germany, the military’s top operational commander this month said security would be strengthened at installations across the country in response to the threats.
German authorities also blame Russia for an attempted attack in August involving an explosives-laden drone discovered near a Ukrainian cargo aircraft at Leipzig/Halle Airport.
In Romania, intelligence officials announced in October that they had uncovered a Russian-directed sabotage network involved in a fire at a military-industrial complex.
Romanian investigators said the network was looking at other potential targets, including military facilities used to train Ukrainian troops.
The incidents fit a pattern, according to military researchers, who say Russia is stepping up what are known as gray-zone attacks. The term refers to hostile actions that fall short of the standard conception of armed attack.
The Kremlin has conducted a sustained drone surveillance campaign across Europe, including at or near U.S. bases and allied locations where American nuclear bombs are stored, the International Institute for Strategic Studies said in a July report.
Spc. Lucas Yohn learns to operate a Dronebuster Block 4 counter-drone system at Caserma Ederle, Italy, Dec. 2, 2025. Heightened threats from Iran and Russia have led U.S. and allied forces in Europe to step up efforts to secure bases against drone use by adversaries. (Jennifer French/U.S. Army)
The same month, U.S. Air Forces in Europe-Air Forces Africa announced that it had begun deploying laser-based counter drone systems to undisclosed locations across Europe.
“The modern threat has erased the idea of a safe haven,” Air Force Col. Victoria Habas said at the time.
Europe has also seen disruptions at airports, grocery stores and schools amid concerns about hybrid warfare, which can involve attempts to sow chaos and fear in societies.
In Italy, thousands of schools received bomb threats this week, prompting evacuations.
Defense Department schools in Italy were not targeted, but some children of American service members attending off-post schools were affected by the threats, Stars and Stripes reported.
Elsewhere, cyberattacks have inflicted a financial toll on both civilian infrastructure and U.S military communities.
France blames Iran for attacks last month on refrigeration systems at about 700 locations that destroyed food inventories and caused fires.
Meanwhile, unexplained refrigeration failures that struck numerous military commissaries in the United States, Germany and England over the summer are still under investigation.
The Pentagon hasn’t said what caused the outages or who might be responsible for them.
