Is just war unjust?
Traditional theorists seek to justify their extraordinary claim — that those who fight and kill in an unjust war never do wrong provided they kill in accordance with the rules — by appealing to the familiar idea that, while it is not permissible to attack people who are innocent, it can be permissible to attack and kill those who are noninnocent. But the Theory uses these words in a special way. Innocent means “unthreatening,” so that in war non-combatants are innocent while all combatants are noninnocent. Thus, in Walzer’s words, the right not to be attacked “is lost by those who bear arms…because they pose a danger to other people.” This is true of the just and the unjust alike. “Simply by fighting,” Walzer claims, they lose “their title to life…even though, unlike aggressor states, they have committed no crime.” According to this view, all violent action that is defensive is self-justifying, assuming it is also necessary and proportionate.
This account of defensive rights accords no significance to the distinction between wrongful aggressors and their victims, or between unjust and just combatants. Each has a right of defense against the other. Such a view has no plausibility outside the context of war. If a police officer, for example, is about to shoot a murderer on a rampage, the murderer has no right to kill the officer in self-defense, even if that is the only way to save himself. In this and other situations outside of war, the morality of defense is asymmetrical between wrongful aggressors and innocent victims (and third parties who attempt to defend them). While the victim has both a right against attack and a right of defense, the aggressor has neither. This asymmetrical understanding of the morality of defense is found even in the traditional doctrine of jus ad bellum, for the Theory accepts that the morality of defense among states is asymmetrical. It is only in the doctrine of jus in bello, which applies to combatants, that the morality of defense is symmetrical. The Theory thus comprises two distinct accounts of the morality of defense — an asymmetrical account for states and a symmetrical account for combatants.