In an effort to prevent another major war, an organization for the maintenance of collective security was established, the League of Nations. The Covenant of the League was officially declared in Paris on 28 June 1919, and Canada was admitted as an independent member of the League.
The League of Nations was created as a mechanism to settle disputes between states. In the event of aggression by any nation, Article X of the League's covenant called for the use of military intervention by member states to enforce collective security. President Woodrow Wilson of the United States first proposed the League, but Congress refused to approve American membership in the organization. The League admitted Germany as a member in 1926 and the Soviet Union in 1934.