During his first year of college, Robertson and some friends signed up for military duty after the Japanese bombed Pearl Harbor in 1941. He began his military service in Fort Sill, Oklahoma, before being sent to the horse cavalry at Fort Riley, Kansas, and then to officers' school at Fort Knox, Kentucky where he was commissioned a Second Lieutenant in the Armed Forces. From there he was sent to the Engineer School at Fort Belvoir, Virginia. After stateside training he served as a tank commander in the 777th Tank Battalion in the North African campaign. He was standing in the hatch when his tank was hit by enemy fire. His tank crew were killed, but he was blown out of the hatch and survived with shrapnel wounds to his lower legs, the scars of which he still bears. Fully recovered, he went on to serve with the 322nd Combat Engineer Battalion during the European campaign. He was wounded a second time, this one in the right knee during a mortar attack. Again he made a complete recovery.
