My mom's husband was in Vietnam. He passed away several years ago, due to cancer from something he was around over there. He had some violent dreams where he'd sometimes wake up and think he was still there. We never knew exactly what he did there. He always said he was a clerk, but sometimes he would tell these very vivid stories about his experience, I think maybe he just didn't want my mom to know, so I always figured he had done some pretty bad things over there. He just never told me what he really was doing. And I know he was disillusioned with war after being there.
He also hated Trump with a passion. His reason is pretty much the same as mine. Trump talks tough, says he knows more about the military than anybody, criticized the military when he wasn't in office, makes stupidly bold claims and denigrates actual war heroes like McCain. Yet when he was presented with a chance to back it up, and I think we can all pretty much guess Trump's personality isn't much different than it was, he chickened out. McCain served and he could have avoided it. If Biden had said the same things, or even Clinton, the right wouldn't have let them hear the end of it.
Yet Trump acts like he's a tough guy when he is just a coward.