An organization for international cooperation established in 1919 by the Versailles Peace Settlement. A League covenant embodying the principles of collective security, arbitration of international disputes, reduction of armaments, and open diplomacy was formulated. Germany was admitted in 1926, but the US Congress failed to ratify the Treaty of Versailles, containing the covenant. Although the League, with its headquarters in Geneva, accomplished much of value in post‐war economic reconstruction, it failed in its prime purpose as a result of the refusal of member nations to put international interests before national interests. The League was powerless in the face of Italian, German, and Japanese expansionism. In 1946 it was replaced by the United Nations Organization.