Deckman, I can only go by what I remember of the regulations of the period. In the Illinois Army Reserve National Guard, failure to make three drills without excuse could get you involuntarily activated. Miss THAT and the FBI came around inquiring about you.

This may have varied from state to state. And of course, the Army Reserve would have worked by different rules.

GII was in the Texas Air Guard; I was basing my response upon what I (think?) I remember of the regulations of the National Guard in the early '70s, when GII was in the ANG. And, of course, he was an officer and I just a poor, benighted, three-stripe sergeant who didn't get ordered to a disciplinary unit. Of course, I did go to drills and summer camp and state duty and even, God help me, was involuntarily activated with the whole damned unit (most to Chu Lai, me to Korea).