100 years after the Paris Peace Conference and in view of the voices that the world is once again on the eve of ‘Sarajevo’, it seemed timely to offer a critical reflection on the achievements of the Conference. Its focus was the League of Nations, the first universal international organization – an expression of organizational idealism in international relations. In the catalogue of decisions of the Conference there are norms which: – codified international law; – developed law; – and changed it. The international order that was created was based on values and the institutions had important functions in it. The values that formed the system, which were at the origin of the general solutions adopted, have passed the test of time. It was supposed to be based on the internalization of values and objectives; and this was not achieved. The image of the Conference and the LN is, first and foremost, the result of another war. The blaming of the Conference, the treaties, the system of organization – the ‘forum’ for the war is (infantile) anthropomorphising; it is justified by the suffering of millions and the memory of it. However, the passage of time requires a critical reflection on the Conference and its achievements. One of the prisms of this reflection is international law. The article offers conclusions resulting from the analysis of the Conference and its findings.