A lot of circumstances in the world led to the start of World War 2. In lots of ways, World War 2 was a result of the chaos left by the first world war. Shown below are a few of the main reasons World War 2 happened. The Allied Powers and Germany used the Treaty of Versailles to end the war. Germany lost the war, so the treaty negatively affected Germany. They were forced to "accept the responsibility" of the damages suffered by the Allies in the war. This agreement made Germany pay war reparations, which were very costly. Germany’s economy was left in ruins and that was one of the major problems with this treaty. German’s were poor and hungry and their government was a wreck. In the time prior to World War II, Japan had been growing quickly.