Having been in the military myself, I believe as long as you are onn active duty, your driver's license, even though expired is still good. There is no need to go home every few years to renew your DL.
"The Marines I have seen around the world have, the cleanest bodies, the filthiest minds, the highest morale, and the lowest morals of any group of animals I have ever seen. Thank God for the United States Marine Corps. Eleanor Roosevelt, 1945"