Cameron was commissioned into the British Army in 1936, aged 19, joining the Queen's Own Cameron Highlanders. After commissioning, he served in India, and was the aide-de-camp for a General while stationed in Egypt. Cameron served during the Battle of Gazala in 1942, which ended in the capture of the port city Tobruk by Axis forces and the surrender of thousands of Allied personnel. Along with two other soldiers, he escaped Italian custody in 1943, but was recaptured by German forces six weeks later, eventually being freed after several years by American soldiers. He returned home, and after marrying, was assigned first to Balmoral Castle and then to the Eaton Hall military training school. He retired from military service in 1947.