Grew was a personal friend of President ROOSEVELT who served as Ambassador in Japan from 1932-41. He was an expert on Japanese affairs and realized that the Japanese Cabinet was not in control of the wilder elements of the Army. He worked hard to avoid war in the Far East but in September 1940 he sent the ‘Green Light’ telegram which stated that ‘a show of force together with a determination to employ it if need be’ could ‘alone contribute effectively’ to maintaining the status quo in the Pacific. Cordell HULL followed Grew’s advice and this led to the placing of an oil embargo on Japan and eventually to war. Grew was arrested after Pearl Harbor and returned to the USA in the summer of 1942 when he was exchanged for Japanese diplomats. He then served as an adviser on Japanese affairs in the State Department.