Campbell was a member of the First Reinforcements that arrive at Dili, Timor, aboard M.V. “Kalama”, on 22 Jan 1942, prior to the Japanese landing. He joined the unit as a Lieutenant. He was later the Officer Commanding one of the Sections of “D” Platoon.
After the campaign on Timor, he embarked with the unit, for Australia aboard the Royal Dutch destroyer “Tjerk Hides” on 11 Dec 1942.
After leave and reorganization, he embarked with the unit for New Guinea aboard S.S. “DUNTROON” on 17 Jun 1943 as a Lieutenant, Officer Commanding, No 8 Section, “C” Troop and returned to Australia with them aboard “TAROONA” on 3 Sept 1944.
He was discharged on 19 Oct 1945.