CEVAP:

One of the most significant developments of the 20th century was the outlawing of war as a legitimate instrument of foreign policy. It was realized with the establishment of the United Nations after the Second World War; however, there were also initial attempts for this. The first attempt for it came after the First World War with the establishment of the League of Nations. However, the League system did not prohibit war or the use of force, but it did set up a procedure designed to restrict it to tolerable levels. The Covenant of the League declared that members should submit disputes likely to lead to a rupture to arbitration or judicial settlement or inquiry by the Council of the League. In no circumstances were members to resort to war until three months after the arbitral award or judicial decision or report by the Council. This was
intended to provide a cooling-off period, and league members agreed not to go to war with members complying with such an arbitral award or judicial decision or unanimous report by the Council (Shaw,2008: 1121-1122).
The first real attempt for the prohibition of war was materialized with the initiation of the BriandKellogg Pact in 1928. As one of the great milestones of world history the Pact counted only two substantive articles. Before these attempts war was a legal means of foreign policy, even the central way in resolving disputes between states. No one could be tried for waging a war because it was not a breakdown in the rule of law. The outlawing of war in this sense was realized with the establishment of the UN after the Second World War, in 24 October 1945.