Wasn't this 1979? Didn't we have a foreign country take a bunch of American's captive that year? Seems if he was serious, that event would have fired him up...
And during the term of his imagined enlistment, the hostage rescue, Beirut, Grenada and Panama.
Plenty of chances for combat if that's what he desired.
I'm sure the Chicago Police Department was hiring at the time, wonder why he opted out of that form of community service.