Well the U.S. Military seems to mention it but not dwell on it much..might be different between branches/indoc. centers.

Essentially if you reject what you perceive to be unlawful orders it will be decided in the Military court-system, you'll be punished if it turned out to be a lawful order(and you just didn't like it, say?)
If you encourage others to also not follow orders(as opposed to just stating your reasoning) then you're guilty of mutiny anyway. That is my rough basic interpretation of it.

U.S. soldiers have gotten nailed for war-crimes on an 'individual-basis' before but.. you know..... *coughcough*