Treated Like Mushrooms, Kept In The Dark, And Fed On...

From September 24, 1941, the Japanese Consul General in Hawaii sent
a special series of messages back to Japan. This series of messages
made it obvious that Pearl Harbor was a target. Included were details
of the disposition of warships in the harbor. On October 9, 1941, the
first of these messages was intercepted. But FDR never, at any time,
distributed a copy to the military Commanders in Hawaii.