Actually, that is based on the branch of military service yo uare in as well. I am in the Marine Corps and when I was stationed in Okinawa, the legal drinking age for locals was 20.
Great!...nope...the Army, Air Force, and Navy could all abide by those rules, and drink legally at 20. However, I can't remember the amount of Marines I knew that were punished and had money and rank taken away from them for drinking under the age of 21.
So, although still off topic, I don't want anyone to join theMarine Corps thinking they can drink under 21...wont happen my friend.