This title appears to be self-contradictory. How can there be a law of war if war is outlawed? This apparent contradiction disappears, howover, if the distinction between “ war in the legal sense” and “ war in the material sense” is kept in mind. War in the legal sense has been in large measure “outlawed” ; that is, the international law conventionally accepted by most states no longer recognizes that large-scale hostilities may constitute a “state of war” in which the belligerents are legally equal. Such hostilities may, however, occur constituting war in the material sense, and “laws of war” may regulate such activities. This has, in fact, long been the situation within the state. All states “outlaw” domestic insurrection, rebellion and civil strife, yet if these events occur, they apply the laws of war to the hostilities involved in their efforts at suppression. The first modern codification of the law of war was, in fact, issued by the United States to apply to civil strife. Lieber's Code, however, distinguished the applicability of the rules of land warfare in international war and in civil war:

Despite a widespread hope that in the United Nations mankind had created an organization which would eliminate warfare, events have unfortunately proved that international conflict, with all its attendant legal problems, is not yet a dead issue. Although the United Nations has not extirpated armed conflict, it has, by its very existence and by its actual and potential role as a participant in, and even as an originator of, military actions, altered, of necessity, the status both of Members and nonMembers in the course of such an action. This is a study of that status, together with a consideration of the necessary concomitant changes in the concept of neutrality in the modern world. The laws of neutrality will first be briefly considered; the effect of the League of Nations period will then be examined as background for a comparison with the current period; and the effect and influence of the United Nations will then be studied in greater detail.

It is generally agreed that the modern origins of the law of nations are to be found in two great early seventeenth-century works, Suarez’ Tractatus de legibus ac deo legislatore (1612) and Grotius' De jure belli et pacis (1625). Among their contemporaries, Suarez and Grotius were moderate and mediating men, and they were therefore particularly aware that the basic problems of international diplomacy—the just causes and conduct of war, treatment of prisoners, acquisition of sovereignty and booty through conquest, neutrality or intervention, maritime law, treaties, etc., had become profoundly complicated by the growth of a conscious and extreme political nationalism.

The problems raised by the unwillingness en masse of the North Korean and Chinese prisoners of war to be repatriated in accord with the rights given them under the 1949 Geneva Convention, present, in a revealing perspective, the test to which the Korean conflict has put positive international law. Apart from the final solution, which is based on a United Nations resolution grounded in valid international law, the attitude of both sides throughout the Pan Mun Jom negotiations raised quite sharply several questions. Standing out among them was, on the side of the United Nations, the policy question of confidence in, and application of, international law, and the legal question of its dynamic interpretation and adjustment. More generally and, in part, de lege ferenda, the ideological basis of the war prisoner issue raised a fundamental question of values, and added a new dimension to one of the central foci in the modern development of international law: the rights of individuals, per se and in their relations to the rights of states. Viewed from this standpoint, the prominence of the prisoner-of-war question in the armistice negotiations looks much less incidental or opportunistic than some current commentaries may have made it seem.