Division, both at Biggs Air Force Base, Texas, and the 19th Air Division at Carswell Air Force Base, Texas. Ryan became director of materiel for the Strategic Air Command in June 1956, and four years later assumed command of SAC's Sixteenth Air Force in Spain. In July 1961, he was named commander of the Second Air Force at Barksdale Air Force Base, Louisiana. In August 1963, Ryan was assigned to the Pentagon as Inspector General of the Air Force. A year later, he was named vice commander in chief of the Strategic Air Command (SAC) at Offutt Air Force Base, Nebraska. Strategic Air Command In November 1964 Ryan was appointed as the next Commanders-in-Chief of The Strategic Air Command (CINCSAC) following the retirement of the current CINCSAC General Thomas S. Power. Ryan assumed his duties as CINCSAC On December 1, 1964, and became its fourth commander in chief and was the first CINCSAC to be educated at West Point. During his tenure as Strategic Air Command Commander, Ryan oversaw the early staged of Strategic Bombing campaign during the Vietnam War and also Strategic Air Command role within the war. As part of the Strategic Air Command involvement in the Vietnam War, Ryan under the direction of Secretary of Defense Robert McNamara ordered the deployment of several Strategic Air Command fleet of B-52 Stratofortress and Boeing KC-135 Stratotanker into Southeast Asia. The B-52 and Boeing KC-135 fleet was then deployed into U-Tapao Royal Thai Navy Airfield following an agreement with Governments of Thailand and operating the base in-cooperation with Royal Thai Navy. As a result, the U-Tapao airbase became the main Strategic Air Command base for its Southeast Asian operation, especially for its operation for the Vietnam War air campaign. Ryan also the early staged of Operation Arc Light, which purpose was to provide bombing support that include enemy bases and supply routes and also providing air support for gorund combat operations. In order to support the Operation Arc Light, several fleet of Strategic Air Command's Bombers Aircraft, including its fleet of B-52 Stratofortress was deployed into Andresen Air Force Base in Guam and Kadena Air Force Base in Okinawa, Japan. Operation Arc Light played crucial role in the strategic bombing campaign during the Vietnam War and especially in providing the bombing air support to ground combat troops in the battlefield of Vietnam. On February 1, 1967, Ryan was assigned as