You don’t need a fancy kill switch, just stop sending parts and updates, any sustained conflict will do the work.

Any F35 bought by Europe is nothing short of lunacy. You don’t buy from people hell-bent on having conflicts with you.

The UK alone produces 15% of the parts required to assemble the F35. Around 25% of the jet is manufactured/produced by the other partners of the program.

Heck the F35B only exists due to the UK demanding it. They have access to the source code (and so do Israel).

Due to political engineering some significant parts are manufactured in partnership countries. That supply chain is also a vulnerability for the US albeit to a lesser degree.

Excatly and even more they are stripped version. Export version is always inferior.

Except the Israeli versions obviously. These are at least on par with domestic.

Iam not sure about this, may be true. But in general exported products are always less capable. Be it f35, brahmos or s400.