This will divide the military, and that's what the Chinese want.
I assume you're referring to the American military. And yes, there was a very bad "slope" in the 1968 to '72 era. Let's face it, the jokes are over, after all, the joke might refer to your dad or your uncle.
I believe that there was also a very strict "reject rate" at this time. One of my freshman class (living in student-housing) came back almost at the end of the year. There was a mistaken belief that if you didn't get yourself into "an injury," dismal grades, or tickets to Canada you'd be watering a Vietnamese jungle with napalm. The guys I knew served in The States like most guys. And most of the guys doing the fighting had the skills to actually fight, and did so with distinction.
My discussion with a soldier at one of our "meeting and greets" lasted within two, perhaps three seconds. He saw the simple word "asthma" in my sheet and told me to take up "wall-papering..."