I don't recall the "real" facts of why Trump didn't want to go to Vietnam and take a chance of getting his ass shot off. If you are considered to be rich, maybe, gifted, young, have a bright future ahead, why would you volunteer to join in a war, a war considered to be terribly flawed--even at the time--a war history now sees, as , maybe, the biggest human waste of life story in American history [throw in those poor hapless Vietnamese, too]?
Just because you don't want to lie side by side, in a tall grass-field, and watch many of these gungho volunteer's get blow to bits [I would guess, most, had a bleak future, some were likely blinded by the power of packing a deadly weapon, were under-educated--or just plain dumb,too--or needed a job], doesn't mean you're a coward, and I certainly know, Trump, is far, far from being a coward. He is under heavy fire, constantly, and you can see, this man is not backing down. He has his neck on a platter right now, and those other crazy nut's McCain didn't speak of, would like to end his campaign with some chosen method of violence, so he, or they, could become one of those, so-called, heroes.
War should be the last resort of any young, heathy minded, American. Avoiding it like the black plague, to me, is the method that makes sound, logical sense.
Now, if you're drafted, you still have the moral obligation to choose the life you want to lead and worry about the conquences later. This may be what Trump must face, but I do not see choosing to go to war as always a smart decision for all young, bright, American kids.
McCain's father was a high-ranking officer, so his situation was profoundly different. He chose to follow his father, as many son's choose to do.
That's exactly what Trump did, and lucky for him, it made some real good-cents, doing just that. [Pun-time]