social contracts are not a myth.
if we lived in a little village, and the vikings rowed up on shore, would you watch your wife and kids be taken as slaves or slaughtered, and all your possessions be stolen while the rest of the village fights, or would you take up arms.
a position of non-violence only works against CIVILIZED opponents who do not really want to kill you, when facing barbarians who are entirely disinterested in your continued survival, or actively desiring your death, pacifism is suicide. if your pacifism allows the deaths of people who were depending on you, you might as well become part of the viking crew.
also, nice invocation of the worst aspect of social contracts in a transparent attempt to Godwin away the reality.
some people prefer to be led, blindly taking theo orders of their superiors through conditioned obedience, a concious suppport of the agenda, or a delight in the power they get as part of the heirarchy, this does not mean every man who ever took up arms in defense of his nation is a murderous bastard, a blind unthinking sheep or a weak willed coward afraid of the social stigma od taking a principled position.
likewise all those who claim a "principled position" are not courageous heroes standing up to tyranny, sometimes they really are just lazy leeches who want all the benefits of society, but not any of the responsibilities incumbent on members of society, like paying taxes, obeying laws which may contradict your own desires, and yes, taking up arms in defense, or even offense if need be.
or was america's action in ww1, and ww2 entirely offensive to your sensibilities?