That doesn't always work so well. If some Viking expedition is coming to pillage your "civil society," for example, there's really not much you can do except to fight. Of course, you can decide who to support or oppose as your moral imperative, but don't be surprised if it has negative consequences to you.
If a war comes to you, then you've got to fight a war and an eye for an eye is the way to do that. But that's no principle on which to organize a civil society.
