US Military Intelligence Division

From 1918 to 1941, the US military attaché, US Military Intelligence Division (MID), Japan, produced reports relating to Japanese military, political, social, and economic development. During this period the Japanese Empire consisted of the home islands, the former Kingdom of Korea, which was annexed in 1908, portions of Siberia, the former German Pacific island possessions seized by Japan following World War One, the dependent Kingdom of Manchukuo (Manchuria), and the occupied territories of northern China seized after 1931. The major function of the MID was the collection of military information about foreign nations. Military attachés and observers assigned to foreign countries were the principal means by which the MID collected such information. The main duties of the military attaché were to observe and report on the training, organisation, equipment, doctrine, and operations of foreign armed forces. Although the US first dispatched military attaches to foreign countries in 1889, it did not accredit an attaché to Japan until the outbreak of the Sino-Japanese War in 1894. Two years later a second military attaché was sent out, but the Spanish-American War cut short his tenure. A permanent military attaché was finally assigned in 1901 when the US and Japan were co-operating closely in the suppression of the Boxer Rebellion in China. For the subsequent forty years, until the Japanese attack on the US naval base at Pearl Harbor, a US military attaché was assigned to Japan. During the period 1918-1941, the military attaché's office in Tokyo usually had two assistants and a number of 'language officers'. The latter were assigned specifically to learn Japanese whilst attached to Japanese Imperial Army regiments as observers. While the military attaché advised the US Ambassador to Japan on military matters, acted as a liaison between US Army and the Japanese Imperial Army Headquarters, and gathered and disseminated intelligence, the 'language officers' translated training and technical manuals and reported on conditions in Japanese military units.