Upon completion of this course in 1931 he returned to Japan and attended the Japanese Imperial War College. The next year he became military attaché at the American Embassy.
From 1922 to 1924 Bratton learned Japanese as a student officer in Japan, followed by an appointment to be an assistant military attaché in Tokyo. In 1926 Bratton became a battalion commander of the 45th Regiment of the Philippine Scouts, then returning to America to attend the General Staff School at Fort Leavenworth in 1929.