The Japanese Messages That We Decoded Before Pearl Harbor

John coster: Officials knew dakoda japanese transmissions and learned of the attack on pearl harbor, yet did nothing to warn our military. Coster explains intent on behaving in such a way as to make an early peace possible. The Japanese embassy had proposed to issue a formal declaration of war in washington a half hour before the actual attack on pearl Harbor. American dekoders were on duty all night, so the white house knew about the message before the embassy did.