As much crap is is going on in the world right now, the US military still has some scruples. They don't just blindly follow Trump's orders. And especially wouldn't just fire into their countrymen. Trump hasn't managed to take over every institution yet. Especially the military.
Service members know how to complain and think for themselves. And if something doesn't seem right, they will clarify the heck out of it and push back. It's not the Russian military