With heightened tensions between Europe and the United States over NATO and Ukraine, the myth of an F-35 “kill switch”, which would supposedly allow the Pentagon to disable foreign-operated F-35s, is fueling speculation and debate.
In the shadow of escalating tensions between Europe and the United States over NATO commitments and the war in Ukraine, a persistent myth about the F-35 Lightning II has exploded online: the notion that the Pentagon has embedded a “kill switch” in the fifth-generation fighter jet, allowing it to remotely disable or impair the aircraft operated by foreign allies.
With over 1,100 F-35s in service across 16 armed forces worldwide, this rumor has gained rapid traction online, stoking fears among nations like Germany and Canada about their military sovereignty—and U.S. control in a time of significant geopolitical uncertainty.
The “kill switch” narrative posits that the U.S. can deactivate or limit the combat functions of F-35s sold to allied nations, effectively holding a veto over their military operations. This concern has echoed in X discussions, with users claiming, “Europeans are now worried if there is a kill switch in all the American weapons sold to Europe! (Answer: Yes ).”
Some online voices claim the jet’s eight million lines of code hide a backdoor for remote deactivation, and many others urge Canada to cancel its $14.5 billion F-35 order, citing fears of U.S. ability to “brick” the jets.
The myth’s resurgence comes as distrust toward the new Washington administration grows, with some European lawmakers and online commentators speculating wildly about U.S. intentions amid Trump’s recent freezes on military aid to Ukraine and intelligence-sharing pauses.
Web reports, including statements from Belgian and Swiss officials, deny the existence of a physical kill switch. However, the fact that the F-35 is a software-defined weapon system (roughly made of +8 million lines of code) of highly networked nature, reliant on systems like the Autonomic Logistics Information System (ALIS), its successor Operational Data Integrated Network (ODIN), and software updates, has raised legitimate questions about U.S. influence over allied operations.
But is this the real problem?
U.S. Control Over F-35 Operations: Beyond the Myth
Recent revelations about U.S. policy restrictions on F-35 operations add a new layer to the debate. According to the 350th Spectrum Warfare Group’s F-35 Program Support Cell, international F-35 operators “are not allowed to conduct independent test operations outside of the Continental United States (CONUS) based on U.S. policy. United States Government (USG) security rules and National Defense Policy (NDP) require that U.S. citizens perform specific functions in order to protect critical U.S. technology.”
This policy, detailed on the U.S. Air Force website, underscores the U.S.’s tight grip on the F-35’s advanced systems, limiting foreign operators’ ability to test or modify the aircraft independently. For NATO allies like Italy, Germany, and the UK, this restriction heightens concerns about operational sovereignty, especially as they rely on the F-35 for critical missions, including nuclear deterrence.
By the way, as of now, Israel is the only country permitted to operate a fully independent system for its F-35I Adir.
While this policy doesn’t constitute a “kill switch,” it amplifies fears of U.S. control, particularly as European nations question their dependence on American technology amid strained transatlantic relations. Wolfgang Ischinger, former head of the Munich Security Conference, told Bild that if the U.S. were to restrict German F-35s as it has with Ukraine’s F-16s, “then the issue of contract cancellation may be considered.”
ALIS and ODIN
The F-35’s logistical backbone, ALIS, was designed to streamline maintenance, supply chain management, mission planning, and debriefing for the global fleet, as described by Lockheed Martin:
“ALIS integrates a broad range of capabilities including operations, maintenance, prognostics, supply chain, customer support services, training, and technical data… transmitting aircraft health and maintenance action information to technicians worldwide.”
Using radio frequency downlinks, ALIS pre-positions parts and maintainers to minimize downtime, but it has struggled with data inaccuracies and inefficiencies, earning it a reputation as one of the F-35’s most troubled systems.
To address these issues, the U.S. Department of Defense is transitioning to ODIN, a cloud-native system aimed at improving sustainment and readiness. According to the F-35 Joint Program Office, ODIN will “decrease F-35 administrator and maintainer workload, increase mission capability rates for all F-35 variants, and allow software engineers to rapidly develop and deploy updates in response to emerging warfighter requirements.”
ODIN promises more efficient communication, edge processing, and less centralization to address export customers’ concerns about sharing sensitive data with the U.S. manufacturer.
Critically, neither ALIS nor ODIN interface with the F-35’s operational controls. As the Government Accountability Office (GAO) has noted, their shortcomings relate to maintenance and data management, not the ability to command or deactivate the aircraft in flight.
Therefore, even if the U.S. were to cut access to these systems or withhold spare parts, the F-35 would remain flyable, though maintenance would become far more complex.
A deeper vulnerability: Software Upgrades and the MDF
Beyond logistics, the F-35’s reliance on U.S.-provided software updates makes the weapon system really vulnerable.
Software upgrades, managed by the U.S., ensure optimal performance and security, but withholding them would leave the aircraft operational, albeit with outdated capabilities.
Think of the F-35 like a modern smartphone: a cutting-edge device that relies on constant software updates to stay at the forefront of technology. To unlock new capabilities, run the latest applications, and leverage innovative features, it must be continuously upgraded.
If you stop updating your smartphone, it doesn’t suddenly stop working as you can still make calls and send messages. But over time, it becomes outdated, unable to support new apps, security patches, or advanced functionalities. Eventually, it reaches a point where it can only perform the most basic tasks, making it irrelevant.
To a certain extent, the F-35 operates the same way. It’s not just an aircraft, it’s a flying networked combat system of system, dependent on software-driven upgrades for mission success. Without these updates, the F-35 can still take off and fly, but its ability to fight, adapt to new threats, and penetrate advanced defenses will be severely compromised. In modern warfare, where technology evolves at an unprecedented pace, staying ahead is not optional, it’s essential.
Famous journalist, writer and, industry executive Bill Sweetman offers a more nuanced perspective on X, arguing that the real issue isn’t a “kill switch” but the F-35’s Mission Data File (MDF). Responding to one of the X posts, Sweetman tweeted: “Most F-35 posts that start with ‘debunk’ miss something important… It’s not just a matter of ‘updating software.’ The Mission Data File (MDF) is the electronic battle manual for the F-35… It provides known target characteristics for the fusion engine that IDs targets with minimal emissions.”
He explains that the MDF enables critical functions like plotting minimum-detectability flightpaths (the “blue line” track), managing communications, and hosting electronic orders of battle—capabilities essential for countering modern threats like Russian air defenses.
In a December 2022 article about the Italian Air Force producing its first MDF file for the Italian F-35 fleet, the U.S. Air Force explained:
“Aircraft rely on MDFs to provide pilots with the awareness of what potential threats may be in an area and how to counter them, such as radars and surface-to-air missiles (SAMs). The information comes from what aircraft sensors pick up during flights and is driven by the mission data. Upon landing, the pilots review their tapes and provide feedback on MDF performance to improve future performance.”
Sweetman emphasizes that MDF updates are “essential” and “rapid and frequent” during conflict, managed by a 90-person team at the AustCanUK Reprogramming Laboratory (ACURL) at Eglin AFB in the U.S. Without these updates, the F-35’s combat effectiveness could be severely compromised, effectively limiting NATO allies’ operational autonomy. This dependency, he suggests, isn’t about a physical “kill switch” but about U.S. control over the jet’s software-driven capabilities, a strategic vulnerability that transcends the logistical concerns of ALIS and ODIN.
Why worry about the F-35 when almost everything in defense already depends on the U.S.?
The F-35 “kill switch” myth underscores a deeper tension within NATO: the balance between collective defense and national sovereignty.
“On F-35 fears, I get it – there is real dependency. But if all your targeting capacity, BLOS comms, penetrating/orbital ISR and the munitions you assume you’d fight with in a war are US-provided; then dependency on the US for MDFs and ALIS/ODIN for F-35 isn’t your main problem,” Justin Bronk, Senior Research Fellow for Airpower and Military Technology at RUSI, commented on X.
As Russia’s war in Ukraine drags on and U.S. political reliability is questioned, European nations like Germany and Canada are reevaluating their defense strategies. Germany’s use of the F-35 for nuclear deterrence with U.S.-supplied B61 Mod 12 bombs, as noted by Justin Bronk, makes it “100% dependent on the U.S. whatever the aircraft.”
With over 400 F-35s projected for Europe by 2030, per Lockheed Martin, the jet remains a cornerstone of NATO’s air power—but its integration highlights a paradox: its technological edge comes at the cost of strategic vulnerability. The U.S. policy restricting independent test operations outside CONUS, combined with reliance on U.S.-managed MDFs, ALIS, ODIN, and software updates, amplifies fears of over-dependence.
TWZ’s Tyler Rogoway commented on X:
“[…] there is no real replacement for the F-35. You would be sacrificing capability and survivability by stepping away from it. There is a whole ecosystem of capabilities provided beyond just the F-35 aircraft that would need to be established…So major investment would be needed and force structure alterations. Unmanned capabilities and future indigenous fighter programs can solve the capability gap potentially, but this is not in the near term. Stepping away from F-35 isn’t about just getting another fighter.”
While the current crisis will likely drive European defense innovation and diversification, building a credible defense backup plan independent of U.S. support would take decades to arrange and execute, and would require substantial funding.
We’ll see…
