 In the wake of Operation Cottage in August 1943, he traveled in U. S. Army aircraft through the Aleutian Islands.While covering the Pacific, Nicholson was a passenger in the first American plane to land on Kiska after its capture from the Japanese.Following the cessation of hostilities in September 1945, in early 1946, new Director of the Historical Section Colonel C. P. Stacey (1906-1989) appointed Nicholson the Officer-in-Charge of the Historical Section at Canadian Military Headquarters in London.