The League of Nations Union (the League) was established in 1918 to "promote international cooperation and to achieve international peace and security" and operated until 1945. The unprecedented slaughter of the 'war to end all wars' was the impetus for a diversion from the realist approach to relations between states towards an idealist conception, which applies liberal theory to international relations. The League worked towards collective security, multilateral disarmament, recognised and respected international law, and world government as means of attaining world peace. This paper will discuss these ideas and examine their feasibility and will show that although realism provides an effective criticism, application of idealist conceptions would provide a mechanism for world peace.…