Set up as part of Wilson's 14 Points, aimed to prevent war (collective security), encourage disarmament, improve living and working conditions and tackle deadly diseases
League couldn't encourage disarmament, countries signed treaties outside it eg Washington Arms Conference 1921-22, Locarno 1925 and Kellogg-Briand 1928
In September 1938, Chamberlain and Daladier agree to let Hitler take the rest of Czechoslovakia without asking the Czech leader at the Munich Conference – "Peace in Our Time"
In August 1939 Hitler signed the Nazi-Soviet Pact with his sworn enemy, Communist Russian leader, Stalin. Stalin agrees not to attack Germany if they invade Poland – Hitler now free to invade Poland