Earlier quoted context omitted.
Whether there is a kill switch or not is somewhat irrelevant. There is a larger than nonzero chance that there is a kill switch, and the US cannot be trusted anymore. So we have to assume there is a kill switch.
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.
Selling expensive weapons that can never be used against oneself sounds like a pretty significant strategic benefit to me. Are there risks? Sure, but the US could just shrug if exposed. A kill switch seems likely.