A useful source for some information and discussion regarding Pearl Harbor can be found at the web site
Pear Harbor Attacked. Like many sites, there is a message board attached although not quite as lively as this one is. Anyway, one of the topics relates to the intelligence status before the attack.
This post is a review of a book by one Robert Stinnet who would appear to be the person who made some of the original claims regarding JN-25b intercepts that turbonium is mentioning here. The review is long, but toward the end the reviewer gives an accounting of the 25k intercepts being discussed. In short:
Quote:
|
Originally Posted by Philip Jacobsen, LCDR USN (ret)
Again, in 1945-46 analysts decrypted those intercepts from the Pacific that were available in Washington. A total of 26,581 messages in seven different crypto systems were intercepted between 5 September and 4 December 1941. Between 15 March 1946 to 20 August 1947, OP-20-G analysts and linguists from ONI undertook the study of these 26,581 post war decrypts and only 2,413 were considered important enough for full translations. Of these, only 188 were isolated as pertaining specifically to the events of 7 December 1941. This information contradicts Stinnett’s assertion that government censors are withholding disclosure of hundreds of vital decrypted and translated messages in furtherance of the alleged conspiracy by President Roosevelt and many top an middle level government officials. Those 2,413 messages that were translated in this period are available in the SRN series and no other decrypts or translations are available for this period of time.
|
So it would appear that the messages of import regarding Pearl Harbor were decoded after the war and are available to researchers. The remainder are probably the usual detritus of naval message traffic that have little indication of pending operations (materiel casualty reports, personnel reporting, etc.). It's doubtful that they were even kept.
Again, one thing to remember,
none of these messages were decoded before the Pearl Harbor attack, so any speculation about their contents is irrelevant. No one in the US knew what information they contained and they could not be used as any form of warning. Given the staffing levels of the code breaking teams at the time, it's doubtful they could have decoded and translated that volume of messages in time anyway.
edit to add: if the direct link to the post doesn't work, go to the site's message board, go to the category labelled "Intelligence" and look for the thread entitled 'A Cryptologic Veteran’s Analysis of “Day of Deceit."