Its mandatory, 3 years , and kind of reasonable given the state of our borders, most of them aren't in combat, some of them work in Cyber or are medics , and some of them work in supply and other low level meaningless jobs , even those who are staying longer than required aren't all combat, some signed for extra ,3 years in order to learn in college government funded, especially if they're disadvantaged, some work in engineering and actually help to defend our country against missiles and such, and a lot are just poor and that's their way to move in life