No, you're wrong. Remember, when someone like Russia invades countries, it's because their people like to kill, rape and pillage. When the US invades countries, it's because the poor soldiers need to get education and healthcare.

I world put the "some" qualifier before US soldiers.

I've met my fair share that are who you describe, but I've also got some dear friends who worked in the military. One was because his dad is a two star general. The other was because it was the easiest way (for him) to get out of Utah. Both are religious, but they aren't zealots.

I honestly can't say for sure but I doubt it... anecdotally, the few Americans I know who did serve, did so as a way to get higher education paid for. None seem to have any particular love for what they were asked to do

This is of course anecdotal as I said, I do not know nearly enough people to say for sure nor have I read in-depth about this topic