Canada

Nothing in the article backs up the headline claim. The closest it gets is their quoted expert saying that he worries about the US doing to the F-35 what they're doing to Ukraine. He's almost certainly referring to the fact that parts and software updates are produced by the US, who could choose to withhold them, just like they're withholding aid from Ukraine.

Every serious defence analyst has laughed at the idea that the F-35 has a secret killswitch. This would be the dumbest thing ever to include in an aircraft, because there is always the possibility that your enemies could find out about it.

Consider; if an F-35 kill switch did exist, any buyer of the craft could invest the resources required to go over every inch of circuit and line of code and find it, and then deactivate every US F-35. It would be more of a liability for them than it is for us. And, equally, our experts could simply patch around the killswitch on our planes. Nations like Canada and Germany are not lacking in technical expertise.

This bonkers notion seems mostly to be rooted in the broader fear that the F-35 is somehow "too advanced", an idea that largely springs from the diseased brain of Pierre Sprey (seriously, if you chase down every bad thing said about the F-35, odds are ridiculously high that Sprey said it first). Sprey also believed that the ideal design for a modern attack fighter has a machine gun, no missiles, no computers, and no radar.

I'm not joking, not even slightly. Pierre Sprey wanted the modern world to fight Russia with planes that had no radar.

There are valid concerns to be raised about the idea of adopting a craft whose supply chain is centred on the US. That's a discussion that NATO partners should be having. But this "killswitch" nonsense just derails that important discussion into paranoid conspiracy theorist nonsense rooted in the deranged ramblings of a self-aggrandizing madman.