They keep themselves first. Most will end up turning on their masters when they realize the implications. But even then most military and police really are NPCs just doing their tasks. It matters who controls the orders and as we know reading Devolution, the real orders come from the seemingly faceless Combatant Commanders.

It would stand to reason that the military is purging those who won't follow orders so as not to further compromise them. Seriously, if you are getting discharged take it as a blessing and new opportunity for something better.