Giles was promoted to lieutenant colonel in February 1941, to colonel in January 1942, and to brigadier general in March. In July, General Giles went to
Hamilton Field just north of San Francisco where he organized and commanded the 4th Air Service Area Command. Giles received his second star in September 1942. He was named director of military requirements and assistant chief of air staff for operations in March 1943 and chief of Air Staff in July. Giles was appointed lieutenant general in May 1943 and in July was named deputy commander of the Army Air Forces. In this role, he often served as acting head of Army Air Forces because of General Arnold's prolonged illness. In May, Giles went to
Guam to join Major General
Curtis LeMay in planning the strategy of bombing industrial and petroleum targets in Japan. In June, Giles backed Admiral
Charles A. Lockwood's plan to hold airman-submariner conferences with the goal of improving
air-sea rescue operations. Giles was appointed deputy commander of
United States Strategic Air Forces in the Pacific under General
Carl Andrew Spaatz on July 5, 1945. Giles witnessed Japan's surrender aboard the battleship . then on to Washington D.C. At that date it was the longest non-stop Army Air Forces flight, it was the first non-stop flight from Japan to the U.S., and the bomb bay filled with fuel was the heaviest load ever lifted by a B-29. In October, Giles became commanding general of the U.S. Strategic Air Forces in the Pacific; he held this position until his retirement on June 30, 1946. Giles's twin brother Benjamin also served at high level in the Army Air Forces and retired from the military in September 1946 at the rank of major general. ==Honors==