Legitimacy of Defensive War in the Realm of the Idea of Pacificism, A Critique and Analysis of John Rawls’ Thought on the Laws and Mechanisms of a Just War

War as a human phenomenon has been one of the catastrophic problems of human societies throughout history. Endeavors of some philosophers especially during contemporary century, being used to eliminate war by applying human rights and ethics. The output of this corporation is rejection of offensive war and accepting defensive war as justifiable and legitimate. John Rawls considering fundamental principles and emphasizing human rights and ethics, has made attempt to take new steps towards limitation of war. This research is based on analytic philosophy through “conceptual analysis” and “critical evaluation”. It has analyzed Rawls’ viewpoint on basic principles of Just war, reasons of offensive wars and taking part of it as unjustifiable, and reasons of defensive war and participation of it as justifiable. Furthermore, refusal of joining a war and also methods of defensive war in different systems of government are discussed. Critique and evaluation of Rawls’ doctrine on assessment of the specific situation indicate that there are contradictions between his realistic attitude and legal and moral obligations. So findings of the research reveal approval of hidden intervention in other countries by domestic governments based on national security, approval of attack on civilians by governors in emergency situations for the interest of political system, and justifying bombardment of Germany by Britain in Second Word War based on legal and moral constraints.