To the student and practitioner of international law in the twenty-first century, the just war ethic is clearly part of Moral Theology--binding the consciences of ethical people everywhere --but it is not part of international law. Nevertheless, there is today a lingering flavor of the Just War Ethic in debates about issues that are partly moral and partly political, such as: 1. the testing and use of nuclear weapons; 2. combating terrorism; and 3. humanitarian intervention to save lives and the human environment. None of these activities is authorized expressly in the United Nations Charter. What is an unjust war in the twenty-first century? Use of military force in violation of the Charter of the United Nations by a sovereign Nation State. What is a just war in the twenty-first century? Use of military force according to the decisions of the United Nations Security Council. All theories of international law agree on one thing: Pacta Sunt Servanda Treaties must be observed. The Charter of the United Nations is such a Treaty.This is the voice of the Just War Ethic in the era of the UN Charter. Only in the inherent right of self defense against armed attack can a Nation be justified in resorting to military force, without the approval of the Security Council. Returning to the basic question: Are there criteria of Just War in the twenty-first century? Yes. Use of military force as directed by the Security Council --or use of military force in self defense against an armed attack are such criteria. These are the just wars of our century and likely to remain so until the United Nations is replaced by a world government. This Article is neither a political endorsement of the 2003 Iraq War nor a political denunciation of decision-making at the highest level. The question is whether international law regulated the outbreak of war by the requirement that it be a just war. The concluding unresolved issue is whether the 2003 Iraq War conducted by the United States and its coalition was a just war in terms of the United Nations Charter.
Joseph C. Sweeney,
The Just War Ethic in International Law,
27 Fordham Int'l L.J. 1865
Available at: http://ir.lawnet.fordham.edu/ilj/vol27/iss6/2