[Cryptography] Pearl Harbor

[John Levine]

It appears that Henry Baker <hbaker1 at pipeline.com> said:
>-=-=-=-=-=-
>I don't want to start a flame war, but I am interested in the best estimates in 2025 of the state of American knowledge in
>December, 1941 of Japanese intentions.

There is a very long article in Wikipedia on this topic.  I realize it's not the ideal source
but it has 147 references you can look at and a long annotated reading list. 

It's well established that we broke the Japanese diplomatic code, and that when the
Japanese government sent their ambassador instructions to break off relations, the
Americans intercepted and decoded it before the ambassador's staff did. But that was only
a few days before Dec 7 and while it meant something major was going to happen, it didn't
specifically mention Pearl Harbor, and due to bureaucratic confusion the importance of the
decrypt wasn't immediately recognized. The ambassador was opposed to war so it wasn't
surprising they didn't tell him earlier.

It also seems to be well established that the planes kept radio silence, because they
disconnected the radios.

Beyond that, your guess is as good as mine. Read all about it:

https://en.wikipedia.org/wiki/Pearl_Harbor_advance-knowledge_conspiracy_theory

R's,
John