The feds don't care that much, and local cops don't get paid to go looking for idiots on the lam from MSGT. Nobody goes out hunting for anyone who simply goes UA. More often than not, the problem resolves itself pretty quickly. More than likely, he'll either come back on his own or be brought back following an arrest for something else, generally only near a base when they can be transferred easily. Local PD won't pay to extradite them, so if they're not near a base, they usually don't care. It's pretty much as serious as a bench warrant. Unless they're getting popped for something and actually being arrested, cops will often just tell them not to go near a base or they'll get hemmed up.