DEAR HARRIETTE: I have a nephew who is dead set on joining the military. He has been talking about it for a few years, and it's almost time to enlist. He believes that it’s as easy as 1-2-3: He will apply, get in and go to basic training. I hope that's true, but that is not what I have heard from people I know who are in the military. They tell me the admission process is rigorous and that for var…