Once I entered federal service, I became a lot less paranoid about government because I was better informed. I also became smarter and more aware of US issue and world issues. I care more about voting and am far more patriotic now that I understand how good we have it.
I'm ashamed of what I was before, but I know that I would never have accepted mandatory service. Instead, what if we try to bring people to the government, if even only temporarily, by having a guaranteed job program after high-school or college?
Each US citizen gets one free 2 year term job with the government where they can make decent salary and show some job experience while we get a chance to show them what government is really like and raise their awareness and education in a practical work environment.
If the only thing they learn is how very broken we are in some ways, then that's a bonus. If they manage to use their new ideas and enthusiasm to improve us, even better.
This idea would benefit everyone and we wouldn't need to force it down anyone's throat. They'd come to us because they need it.
Not to mention that anyone who'd never used their 2 year term could fall back on it instead of welfare.