In September 1943 during World War II, Dixon was transferred from the RCAF to the United States Army, where he served in the U.S. Army Air Forces and assigned to the 7th Photographic Group, Eighth Air Force, European Theater of Operations.

He was assigned to Headquarters USAF and subsequently served as assistant to the deputy chief of staff, plans and operations, for National Security Council affairs.

In this capacity he was Air Force action officer with the Joint Chiefs of Staff, the U.S. Department of State and the National Security Council.

He graduated from the Air War College in 1959 and was assigned to Supreme Headquarters Allied Powers Europe (SHAPE), Paris, France, as staff missile planner.

On August 1, 1970, he was promoted to lieutenant general and assumed the duties of deputy chief of staff, personnel, Headquarters USAF.

It was under his command that the Red Flag training exercises were started at Nellis Air Force Base, Nevada in order to more realistically simulate the expected combat environment and to reduce the high casualty rate experienced during the early phases of offensive operations in the Vietnam War.

Another driver was the lessons learned during the 1973 Yom Kippur War, where the use of Soviet-supplied integrated air defense systems by the Egyptians and the Syrians had severely restricted the capability of the Israeli Air Force (IAF) to support the ground forces.

Dixon developed a close friendship with the commander of the IAF, Major General Benny Peled that facilitated the prompt supply of U.S. replacement systems to Israel and also of Israeli-captured Soviet equipment to the U.S. Dixon also decentralized aircraft maintenance in order to improve aircraft availability and combat sortie rates.