The League of Nations.

The League of Nations was created during the conference in Versailles, France, 1919, when Woodrow Wilson, the president of United States came up with fourteen points. The League of Nations was a point of Woodrow Wilson's fourteen points. It was created to stop wars by working out the problems with each other, to improve the world, to get rid of weapons, and to enforce the Treaty of Versailles. The League of Nations wasn't welcomed in the …

…to be made unanimously. Also, the Great Depression in 1929 left economies of Europe and America devastated. It made countries selfish and disobey the League, like Japan invading Manchuria. The League was also threatened by Mussolini, Hitler, and Hirohito. They disobeyed the League, like the Corfu incident. So overall, the League had failed. "The League of Nations failed because it was weak from the start" (Richard Fuller, http://www.johndclare.net/league_of_nations1_Answer.htm)