In a technical sense, all organizations failed to stop WWI, but you're probably after the "League of Nations", the forerunner to the "United Nations".
The league of nations failed to prevent it, but so did a lot of other people and nations.
The "League of Nations".
The League of Nations was the peace-keeping body that failed to prevent war. The organization was founded on January 10, 1920 at the end of the First World War.
The US fought that war to stop communist aggression; which it failed to do.
At the end of World War 2 it ceased to exist and the Nuremberg Tribunal declared it a criminal organization.
The League of Nations.
He was a failed artist.
■Because without WW2 the UN would have never been formed. After WW1 they tried something similar (The League of Nations) but the United States didn't take part and it failed miserably. The UN was formed to stop wars and WW2 gave the world a vivid reason as to why such an organization should be formed.
Because god wants to stop the war but it failed
The United Nations .
The United Nations.
World War I stopped in 1918.