The League of Nations was established following the Paris Peace Conference in 1919. It was a multi-national organisation whose stated aim was to prevent war through collaborative policies, arbitration and negotiation.
During the 1930s, however, several countries refused to adhere to collective agreements, and there were withdrawals and expulsions from the League.
For example, Germany and Japan withdrew in 1933, Paraguay in 1935, and Italy in 1937. The Union of Soviet Socialist Republics was expelled in 1939.