That's a double whammy for European countries who signed on to spend hundreds of billions on these planes in the belief that they're part of a NATO security umbrella. Now it seems like NATO will soon be in shambles and the planes might not even fly if that one drunk frat guy with Nazi tattoos running the Pentagon says so.
Finland bought F-35's recently, and the Finnish government is saying that nothing should change because America will hopefully be back to normal before the fighters are delivered. I don't think that kind of ostrich strategy is going to pay off.