Tell him to join the navy. Screw the army. The navy might be not as hard-ass as the rest (except for the seals), but if he'll be safer on a boat somewhere than the desert.

Whatever he decides, just stand by em. Make sure they know you think it's a shitty idea, but if he's stuck on it, back him up. If he leaves home and joins up feeling lonely, then he may come back a different guy than what he left.

I've noticed those looking for a purpose come back from the service changed. Those who go for the job and such ususally come back the way they left..