The Treaty of Versailles said that Germany was the sole cause of WWl and that it had to pay for all of the reparations. Obviously, Germany was in no position to pay for all of the damage done during the war and went into a deep economic depression in the 1920's. In comes Hitler and the Nazi Party. Hitler said if Germans would vote for him and make him the supreme chancellor, he would pull Germany out of the depression and make Germany great again. He said if the men would join the military, in return for building highways he would pay them and they could provide for their families. And that folks, is how Germany became ruled by Nazis.