[GovernmentShrinker]

A high school diploma is required because the military saw that if a kid is a quitter in school, he will be a quitter in Basic.

Given that a lot of kids who try to enlist are coming out of inner city school systems, I don't think that's a safe assumption. Going to school in many inner city high schools is physically dangerous, and means spending the day surrounding by chaos, while having little opportunity to actually learn anything. Given that these schools routinely graduate kids who are completely illiterate, I wouldn't hold it against any kid who decides that graduation isn't a goal worth pursuing.

[Coleus]

they have the ASVAB test to measure intelligence and to determine what job in the military one has the skills, intelligence and desire to do.

And, many could get their GED before entering the military.