Hans Kelsen devoted a substantial part of his legal writings to international law, starting in the twenties and continuing until the end of his life. The topics he tackled from the thirties onwards, especially while lecturing in Geneva, concentrate on how peace relates to law and politics in the context of international institutions. While in Geneva, he developed an extensive critique, targeting primarily the League of Nations, together with his own blueprint for ensuring peace, compiling it in a series of little-known writings. Of particular interest is the peace project that Kelsen compared to legal science, placing it in the political arena, focusing its theoretical part on international justice and its practical part on drafting guidelines for an International Tribunal, at the same time as discussing the postulate of making international justice obligatory. In his work on international law, Kelsen devoted much space to the universal state, a topic that unquestionably constitutes the ideal heart of his internationalist thinking and reveals his global and federal approach, somewhere between Utopia and Realpolitik.
Keywords: International law - Peace - Sovereignty - Collective security - universal state