During Operation Torch in November 1942, Cannon was the commanding general of the XII Air Support Command for the Western Task Force during the invasion of French Morocco. He moved to Algeria as commanding general of the XII Bomber Command. Through March and April 1943, General Cannon organized and commanded the Northwest African Training Command in the Northwest African Air Forces of the Mediterranean Air Command (MAC), the official Allied air force command organization in the Mediterranean Theater. In May 1943, Cannon became deputy commanding general of the Northwest African Tactical Air Force under Commander Air Marshal Sir Arthur Coningham for the Sicilian campaign and the invasion of Italy. He was promoted to major general in June and after MAC was disbanded in December, became commanding general of both the Twelfth Air Force and the Mediterranean Allied Tactical Air Force in the newly organized Mediterranean Allied Air Forces. General Cannon was responsible for all air operations during the invasion of southern France in August 1944 (Operation Dragoon). In March 1945, he was promoted to lieutenant general and named air commander in chief of all Allied Air Forces in the Mediterranean Theater of Operations. In May 1945, Lt. Gen. John K. Cannon became commanding general of U.S. Air Forces in Europe USAFE.