 He joined Jagdstaffel 40 (Fighter Squadron 40) on the Western Front and by time World War I ended, Jeschonnek had shot down two enemy aircraft and received the Iron Cross 1st Class and the Iron Cross 2nd Class.Upon the German defeat, collapse of the German Empire and armistice in November 1918, Jeschonnek joined the "Reichswehr" and served the Weimar Republic.He fought in the Silesian Uprisings as a member of the "Reichswehr"s 6th Cavalry Regiment.