German concerns about American control over the advanced F-35 fighter jets they’ve recently bought are sparking a heated debate across Europe.
Some defense experts are now openly asking: Could the U.S. really shut down European warplanes if it wanted to?
The idea of a so-called “kill switch”—a hidden feature that could disable the aircraft remotely—has gained attention after Joachim Schranzhofer from German defense firm Hensoldt suggested the possibility in an interview with Bild last week.
Others, including former Munich Security Conference chair Wolfgang Ischinger and CDU defense expert Ingo Gädechens, have echoed the concern.
While Germany’s Ministry of Defense says there are no plans to cancel its F-35 deal, the fears reflect growing unease about the level of U.S. control over European military hardware, especially in light of U.S. President Donald Trump’s shifting defense policies and recent aid suspensions to Ukraine.
This was reported by Euronews.
The Jet Everyone Wants — But at What Cost?
The F-35 Lightning II, built by Lockheed Martin, is already in service—or on order—with more than 10 European countries, including Germany, Finland, Poland, Switzerland, and Belgium. The aircraft is praised for its stealth, advanced sensors, and ability to operate alongside NATO forces.
Lockheed itself has called it the “NATO standard fighter of choice” and predicts that more than 550 of the jets will be flying across Europe by the end of the decade.
But the technology at the core of the F-35 relies heavily on U.S.-controlled systems—especially encrypted data links like Link-16 and GPS navigation. That’s where some European defense officials start to worry: What happens if those systems are suddenly turned off or withheld?
Expert: U.S. Doesn’t Need a Kill Switch
Military analyst Mark Cazalet, editor-in-chief of European Security and Defence Magazine, told Euronews Next that while there’s no hard evidence of a “kill switch,” the U.S. could still block the use of the aircraft in more subtle ways.
“The U.S. doesn’t necessarily need a kill switch,” Cazalet said. “They can just withhold software updates, spare parts, or access to critical systems.”
In fact, he believes the question isn’t whether the U.S. can stop the jets from flying, but how easily they could do it if they wanted to. And on that point, the answer is clear: “Mostly yes.”
Replacing the U.S. software—or designing a European system to work independently—would be extremely difficult, he added. That makes true independence hard to achieve, even for major NATO members like Germany.
“You Can Use the Jets Anytime”
Responding to similar concerns raised in Switzerland, Lockheed Martin published a statement this week denying that any such shutdown mechanism exists.
“Switzerland does not need consent if it wants to use its weapon systems,” the company wrote. “It can do this autonomously, independently, and at any time.”
Lockheed said that missiles remain operational even without software upgrades, and countries are free to choose when or if they update their systems. When upgrades are needed, Lockheed dispatches a mobile team to carry them out with the host nation.
Reality Check: No Fighter Jet is Ever Fully Independent
Even with Lockheed’s reassurances, experts say the reality is more nuanced. Modern fighter jets are incredibly complex, and they rely on secure networks, cloud-based mission planning systems, and satellite guidance—all of which are often controlled or hosted by the U.S.
“You may own the plane, but you don’t fully control the ecosystem it runs on,” said a senior European defense official familiar with the F-35 program.
And even if there's no “big red button” to turn off foreign jets, logistics dependence is still a powerful tool. For instance, in other arms deals, countries have blocked the export of ammunition or components to influence policy—like Switzerland delaying shells for Ukraine’s Gepard anti-aircraft systems, or Germany hesitating to approve Eurofighter sales to Turkey.
The timing of these fears is no accident.
With Trump’s return to the White House, European nations are rethinking their dependence on U.S. military leadership. The concern isn’t just about planes—it’s about geopolitical trust.
Germany is spending billions to modernize its air force under the Zeitenwende (turning point) initiative announced after Russia’s invasion of Ukraine. The F-35 purchase is a big part of that plan, but so is strategic independence.
