After his discharge from the German Army, Goerdeler joined the ultraconservative German National People's Party (DNVP). Like most other Germans, Goerdeler strongly opposed the Versailles Treaty of 1919, which forced Germany to cede territories to the restored Polish state. In 1919, before the exact boundaries of the Polish-German border were determined, he suggested restoring West Prussia to Germany. Despite his strong hostile feelings towards Poland, Goerdeler played a key role during the 1920 Polish–Soviet War in breaking a strike by Danzig dockers, who wished to shut down Poland's economy by closing its principal port. He thought that Poland was a neighbour that was less undesirable than Bolshevik Russia was.