Rawls characterizes just war theory as part of the nonideal component of a reasonable Law of Peoples. Speciically, it serves to guide well-ordered peoples in their interactions with what Rawls labels outlaw states. Such states, or the regimes that rule them, fail to honor the human rights of individuals belonging to other societies by launching aggressive wars against them, or they fail to respect the human rights of (some of) the members of their own society by adopting policies that egregiously violate those rights, or both. Indeed, Rawls deines human rights in terms of the special role they play in a reasonable Law of Peoples, namely specifying those cases in which well-ordered (or at least human rights respecting) peoples may resort to war, and the constraints under which they must wage it.

As Rawls describes them, outlaw states believe that the advancement of the state’s rational interest in, for example, economic gain, the acquisition of territory, or the attainment of power, sufice to justify the resort to war. Well-ordered states, in contrast, acknowledge the constraints that the reasonable places on the rational by submitting to a reasonable Law of Peoples that sanctions war in only two cases: the defense of a human rights respecting society against aggression, and forceful intervention to protect those individuals whose own state egregiously violates their human rights. In other words, a reasonable Law of Peoples condones waging war only if it targets an outlaw state.