[ARC5] How the U.S. Cracked Japan's 'Purple Encryption"

[Glen Zook]

Actually, 1:00 PM in Washington, DC, was 7:30 AM in Hawai'i.  Before World War II, the standard time in Hawai'i was 2.5-hours earlier than PST, not an even hour behind any of the stateside time zones.

 Glen, K9STH 
Website: http://k9sth.net

      From: Joe Connor via ARC5 <arc5 at mailman.qth.net>
 To: Robert Eleazer <releazer at earthlink.net>; "arc5 at mailman.qth.net" <arc5 at mailman.qth.net> 
 Sent: Tuesday, December 6, 2016 1:40 PM
 Subject: Re: [ARC5] How the U.S. Cracked Japan's 'Purple Encryption"
   
What's important to remember is that the intercepted pre-Pearl Harbor diplomatic messages from Tokyo did not include a declaration of war, which would have provided at least some notice that Pearl Harbor might be attacked.
The Japanese played it cute. Tokyo instructed the Japanese ambassador to deliver a message to Secretary of State Cordell Hull at exactly 1 p.m. Washington time, which was 8 a.m. Pearl Harbor time and the moment the attack was scheduled to begin. That message, which was delivered an hour late, did not declare war. It simply broke off the negotiations between Japan and the U.S. concerning the oil embargo etc. The message didn't even break off diplomatic relations. U.S. intelligence had intercepted and decoded that message the previous evening. 
What the Japanese tried to do was to set it up so that they could not be accused of launching a sneak attack. However, only a formal declaration of war, delivered before the attack, would have sufficed. Instead, they tried to have a weak message that didn't even break off diplomatic relations delivered at the precise moment the first bomb would fall.
The fallacy of the FDR-knew school of thought is that it presupposes a successful sneak attack was necessary for FDR's plans. Nonsense. If Pearl Harbor had been fully alerted and if the Navy had kicked the crap out of the Japanese attack, the result would have been the same: war with Japan and the American public fully PO'd at an attempted sneak attack. 
   
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