Abstract
This essay argues that the best starting point for discussions of the Principle of Discrimination (PD) is its most basic formulation: In wartime, certain enemy subjects should receive better treatment than others. Other formulations of the PD ? in particular, those centered on the concept of noncombatant immunity ? have sought to identify a single criterion that can be used as the basis for sorting enemy subjects into two (and only two) classes. However, a historical and legal analysis of the principle indicates that three distinct criteria ? the conduct of individuals, their status, and their guilt or innocence ? have all been seen as relevant for determining the appropriate treatment of the enemy. In this essay, I formulate an expanded version of the PD, which calls for the proportionate treatment of enemy subjects based on evaluations of all three of these criteria