As a lieutenant in the reserves, Schulenburg was posted to the reserve battalion of Infantry Regiment 9 in Potsdam. With this elite unit, he participated in the Russian Campaign and was awarded the Iron Cross, first class. However, it was not until his experiences in the invasion of the Soviet Union in 1941-1942 that he became a critic of Hitler's conduct of the war. During this period, his job changed often, and in the end he returned to the reserve battalion in Potsdam. By this time he viewed his duty as organizing the resistance for the forcible removal of Hitler.