As a colonel he fought in the Polish Army in September 1939. On September 23 Colonel Shandruk rescued the 19th Polish brigade from annihilation in a trap. After the war he received the Virtuti Militari cross from Władysław Anders for this action. After capitulation, Shandruk, as a Polish officer, was captured and sent to a German POW Camp, from where he was later released due to his injuries. After falling ill, he was arrested by the Gestapo but set free before the Germans attacked the Soviet Union.