Sergeant Ishem was a member of Company D, 1st Battalion, 24th Infantry Regiment, 25th Infantry Division. He was seriously wounded by the enemy in South Korea on 11 August 1950 and returned to duty on 1 November 1950. He was listed as Missing in Action while fighting the enemy in North Korea on 11 November 1950. He was presumed dead on 31 December 1953. His remains were not recovered. His name is inscribed on the Courts of the Missing at the Honolulu Memorial.

For his leadership and valor, Sergeant Ishem was awarded the Bronze Star, the Purple Heart with Oak Leaf Cluster, the Combat Infantryman Badge the National Defense Service Medal, the Republic of Korea War Service Medal.