Over the years dozens of books have been written on Pearl Harbor, some claiming President Roosevelt knew more, others that he knew less or nothing about the coming attack.
The two best that I have here, arguing FDR knew plenty and actively prevented Kimmel & Short from being properly prepared are:
- Robert B. Stinnett, c2000, "Day of Deceit -- The Truth about FDR and Pearl Harbor"
- George Victor, c2007, "The Pearl Harbor Myth -- Rethinking the Unthinkable"
The Stinnett book goes into infinite details on all the various codes -- which codes were broken, which were not, which codes were used despite "radio silence," which were not used, how fast our guys could decode them, etc., etc.
It is fascinating reading, albeit a bit technical.
Bottom line: according to Stinnett, there was plenty of data available, and those who made certain that it could not be traced to FDR were promoted and rewarded.
The Victor book takes a much wider historical perspective ("historical perspective" is my "thing," so to speak).
Victor sumarizes and reviews the data showing that "FDR knew," and then goes into wider questions of "why?" and "what was Roosevelt's strategy?"
Bottom line: Victor says that FDR expected the attack on Pearl Harbor, but did not expect anywhere near the levels of destruction Japan achieved.
In that sense, Roosevelt was as shocked as everyone else.
But the Japanese attack was necessary -- indeed had been "provoked" by FDR -- in order to get an aroused and united America into the war.
Nothing else would do that job.
Now, since we still have 19 months before "The Big Day," which means plenty of time to argue and resolve all these questions ahead of time, my suggestion is everyone pick out a couple of these books, study them carefully, and then come back prepared for extended debates.
;-)