Military attaché A military attaché is a military expert who is attached to a diplomatic mission ( an attaché ) . This post is normally filled by a high - ranking military officer who retains the commission while serving in an embassy . Opportunities sometimes arise for service in the field with military forces of another state . An early example was General Edward Stopford Claremont , the first British military attaché ( at first described as " military commissioner " ) , who served in Paris for 25 years from 1856 to 1881 . Though based in the embassy , he was attached to the French army command during the Crimean War and later campaigns . The functions of a military attaché are illustrated by the American military attachés in Japan during the Russo - Japanese war years . A series of military officers had been assigned to the American diplomatic mission in Tokyo since 1901 when the U . S . and Japan were co - operating closely in response to the Boxer Rebellion in China . The military attaché advised the United States Ambassador to Japan on military matters , acted as a liaison between United States Army and the Imperial General Headquarters , and gathered and disseminated intelligence . The military attaché ' s office in Tokyo usually had two assistants and a number of " language officers " who were assigned specifically to learn Japanese while attached to Imperial Japanese Army regiments as observers . These " language officers " translated training and technical manuals and reported on conditions in Japanese military units . During the Russo - Japanese War ( 1904 - 1905 ) , military attachés from many Western military organizations served as observers with the land and naval forces of Russia and Japan . The United States Army detailed eight officers to serve military attachés with opposing forces in the field ; and all served from the start of hostilities in 1904 through the signing of the peace protocols in September 1905 . After the war , the reports of British officers attached to the Japanese forces in the field were combined and published in four volumes . During this conflict , some attachés served primarily in Manchuria , and others served primarily in Tokyo . Some , like Italian naval officer Ernesto Burzagli saw service both at sea and in Tokyo . The agreed conditions that allow military attachés to gather information can be misunderstood with fatal results . United States military attaché Maj . Arthur Nicholson was killed March 24 , 1985 , while photographing a military installation in East Germany 100 miles northwest of Berlin . He was reportedly observing from a point not marked off - limits , though near a place that was . According to Sgt . Jessie Schatz , Nicholson ` s driver , there were no warning shots and the Soviets refused to give Nicholson medical attention for nearly an hour . This activity had been agreed to by the United States and the Soviet Union . Such agreements stemmed from negotiations between United States and Soviet commanders in Germany back in 1947 . Soviet liaison teams were conducting similar missions in West Germany . These tours had evolved into a legalized form of intelligence - gathering , usually accepted by both sides . Thus this assassination became a diplomatic incident . In retaliation , the United States expelled Soviet military attaché Stanislav Gromov . Mr . Gromov was apparently selected for his effectiveness in collecting intelligence on the United States for the Soviet Union from his post in Washington .