Air Officer of the Hawaiian Department at Fort Shafter in the Hawaiian Islands from March 1934 to July 1936. He became a colonel in March 1935. Emmons returned to the United States in July 1936 as commander of the 1st Wing, General Headquarters Air Force, at March Field, California, with promotion to brigadier general. Emmons received his second star in March 1939 as part of his appointment as commander of the GHQ Air Force at Langley Field, Virginia, succeeding Col. Frank Andrews, who was not reappointed after four years in the position and was returned to his permanent rank. After the fall of France, the Americans and British increased their military cooperation; Emmons was one of three American military observers sent to London on August 6, 1940. He was promoted to lieutenant general in November 1940 when Army General Headquarters was activated, to make him equal in grade to the field army commanders of GHQ. He retained his command when GHQ Air Force was renamed Air Force Combat Command in June 1941 and made a part of the new United States Army Air Forces. This however caused command difficulties since he was now superior in rank to his boss, Major General Henry Arnold, the new Chief of the Army Air Forces. Emmons was returned by Arnold to Hawaii as commanding general of the Hawaiian Department on December 17, ten days after the attack on Pearl Harbor. He organized the replacement of the island's U.S. banknotes with new dollars overprinted with the word HAWAII; if the area were occupied, U.S. authorities could declare all marked dollars void and thereby render worthless all money which fell into enemy hands (by their capture of banks, businesses, etc.). He also requested Army Air Force Headquarters to send additional planes and received them as rapidly as possible. Emmons built up the forces in Hawaii, anticipating the Battle of Midway. This was the only combat command he held during the war. Emmons promised the local Japanese American community in Hawaii that they would be treated fairly so long as they remained loyal to the United States, and he succeeded in blocking efforts to relocate them to the outer islands or mainland in internment camps by pointing out the logistical difficulties. Returning to the United States in June 1943, Emmons was assigned three months later as commanding general of the Western Defense Command at the Presidio of