The War Guilt Clause
Under Article 231of the treaty of Versailles, Germany was forced to take responsibility for starting the war. They also had to accept all terms of the treaty without having a say in them. Poland was given a strip of German land to access the sea leaving a large portion of Germany separated from the main german land. All German colonies surrendered to League of Nations. They also lost control of the merchant fleet for Germany. And to top it all of the unification of Austria and Germany was forbidden.