if you need a passport for militray reason, you will be issued it. i don't know of any cadets with them, but the midshipmen in glee club were getting them when i was there because they had a group trip to Argentina this past spring break
that being said, you want to have a civilian passport for personal use. unless your travel requires a military passport, you'll want a personal one. they have opportunities here to get passports (that's what i did) but if you have the opportunity to take care of it before you get here, you may as well. plus then you can get a picture that somewhat looks like you (maybe) as opposed to when where your hair is starting to grow back but hasn't yet... lol