Lack of maintenance parts is just a kill switch with a timer.

Jet Fighters need a lot of maintenance, they are not like cars.

So a kill switch in software is not needed. If the US stops shipping parts, then it is only a matter of time before the Jet Fighters is an expensive paper weight.

That's basically what the article says. And that even if there isn't a kill switch, these weapons rely on constant updates and cutting those off is effectively a kill switch, even if it wasn't designed as one.

Having a kill switch "just in case" really is a strategically logical move. Consider the case of Iran: In the 1960s and 1970s, the US delivered several US-built aircraft to Iran, including F-4s, F-5s, and F-14s, some of the most advanced fighters of that era. After the 1979 revolution, US-Iran relations collapsed. Despite the US cutting off spare parts and maintenance, Iran has been able to keep the aircraft operational to this day (likely through effortful reverse engineering). So now there is an adversary that is armed with equipment you provided. The obvious way to avoid that is to install a kill switch.

One of the kill switches are the Intel ME, AMD PSP, Windows OS, Google. Apple? Who knows if they will participate in such national security measure.

Also core routers, interxions, sealines, Level 3 et al.

With absolutely no military experience, I find this thought process hard to believe. Namely that the existence of backdoors is hard to conceal forever, and that their discovery would do worse damage than what Trump is doing now. Given most administrations seemed interested in maintaining friendship with Europe, I don't see the strategic benefit.