Theologists and political philosophers have long sought to identify the conditions under a war is a “just” war, and by extension to determine the impact of war on the human being and society as a whole. This paper explores the literature generated by those seeking to explore the just war, and shall conclude by establishing the principle of justice which best governs the conduct of war in the case of the recent Iraq War and the United States’ rationale for entering this country under the context of conducting a preemptive war.