Posted to Tokyo in 1932, U.S. Ambassador Joseph Grew immersed himself in Japanese culture, and remained well-accepted there even as relations between the two countries deteriorated. In January 1941, Ambassador Grew reported to the State Department that many sources (including a Japanese one) warned of Japanese military plans for a surprise mass attack at Pearl Harbor in case of “trouble” with the United States.
Ambassador Grew Warns of Pearl Harbor Attack
May 17, 2013