I'm suddenly reminded of Starship Troopers where people do not gain the right to speak, vote, et cetera unless they're first joined the army. That's backwards. It is human rights that come FIRST, and the government that is allowed to exist only because we tolerate it.
In "Starship Troopers", the only Right you gained by doing a term of service was the Right to vote. The rest of what we consider "civil rights" you had automagically.
Note also that you did NOT gain the Right to vote by joining the Army. You gained it by leaving the Army (soldiers had no Right to vote).
Note also that "the Army" is misleading, at best. You had to serve a term of service as a Federal employee. That may mean the Army. But, as was pointed out in the book, if you were blind, deaf, and dumb, they'd find something for you to do, like counting the hairs on a caterpillar by touch, so that you could earn the Vote.