There were five main causes that led to World War II. The main controversy was the Treaty of Versailles because it forced Germans to pay all the damages caused in the first world war. This caused the Germans to feel resentment. Although the treaty ended WWI it later became a cause of WWII. Also, the League of Nations was set up among the counties involved to have peace, but it failed at stopping war from happening. This went to show them that it was not a successful source. Germany, under Hitler, then announced their removal from the League of Nations. In order to keep peace, the European nations set up an appeasement plan not knowing this would only give Hitler more power. This led to Hitler becoming very powerful since he was basically getting everything he wanted handed to him.