ABSTRACT
The law of permissible uses of force in international law dates back to ancient Greek and Hindu law.1 Following the Christianization of the Roman Empire, the use of force abroad was driven by the just war doctrine. Under this doctrine, force could be used as long as it complied with the divine will.2 The foundation of this theory was that order was a deterrent to force, and force threatened order.3 At the time, war was used to punish wrongs and restore the status quo. During this time, St. Augustine elaborated and gave authority to the concept of just war (bellum justum) and theorized that war for the purposes of aggression was unjust.4 Natural law theory maintained that lawfulness of the use of force derived from the justness of its cause premised on the assumption that violations of natural law could be vindicated with force to the extent that justice permitted.5
