Cannon went to Hawaii in January 1925, assigned to the 6th Pursuit Squadron at Luke Field on Ford Island, where he became operations officer of the 5th Composite Group. Two years later, he was commanding officer of the 94th Pursuit Squadron at Selfridge Field, Michigan. He returned to Kelly in 1929 as director of pursuit training, with promotion to captain, and became director of training at Randolph Field, Texas, in August 1931. He completed the courses at the Air Corps Tactical School and the Command and General Staff School, with promotion to major in March 1935 and assignment to March Field, California.
In June 1938, Cannon went to Buenos Aires, Argentina, for three years as chief of the U.S. Military Mission. While there, he was promoted to lieutenant colonel in March 1940 and to colonel in January 1941. That October, he went to Mitchel Field, New York as chief of staff of the 1st Air Force, taking command of the 1st Interceptor Command. He was promoted to brigadier general in February 1942.
General Cannon returned to the U.S. in April 1946 as commanding general of Air Training Command at Barksdale Field, Louisiana. In October 1948, he returned to Europe as commanding general of U.S. Air Forces in Europe and in March 1950 was designated commander-in-chief of U.S. Air Forces in Europe. On October 29, 1951, he was promoted to general and appointed commanding general of Tactical Air Command at Langley Air Force Base, Virginia.[4]
General Cannon retired from the service on March 31, 1954. At the time of his retirement, he was senior air officer in point-of-service, holding serial number 3A.