There have been discussions for seven decades about how we got clobbered at Pearl Harbor. Mac did not arrive there until February of 1943, so he could not comment authoritatively on what was true or not about the claim that Washington short-sheeted the Pacific Fleet Commander on decrypted Japanese messages tracking the mooring locations of the American capital ships in the harbor.
Mac talked to Joe Rochefort about it when memories were still fresh and victory was far from certain. He said Joe wasn’t sure that knowing about the message stream would have changed anything in particular, but I was reading about it again. I had time- we got snow last night, most of this winter, and Washington is Predictably Paralyzed. Willow is closed for an unprecedented second night in a row, and I officially have cabin fever. In the meantime, the memories of the placid waters of Pearl Harbor will not leave me alone. This morning it was the Bomb Plot message.
No, it doesn’t refer to some nefarious scheme or plan. “Plot” is Navy-speak for information placed on a map. Like targets you might want to bomb sometime.
That is the intercepted message that might- or might not- have provided the advance information that the Japanese were interested in the precise locations of the American fleet. It might- or might not- have resulted in a different outcome in the attack. Some say that if the fleet was at sea, and might have tried to engage the attacking Japanese and been sunk in deep water, with thousands more casualties, and the proud ships lost forever, not salvaged as they were.
I got a note a week or so ago from a documentary filmmaker in the UK who is married to a pal who is a journalist based in the UK. Vicki Barker is the voice I trust on the CBS radio network. Her husband is interested in doing a documentary on the appalling way that Admiral Husband Kimmel, commander of the Pacific Fleet, and Lt. General Walter Short were hung out to dry in the wake of the disastrous attack on Pearl Harbor.
As I have told you (over and over) I lived and worked in the buildings that survived the Day of Infamy, and I was fortunate to have been a drinking buddy and tipsy Boswell to RADM Donald “Mac” Showers, the last of the JN-25 code-breakers at Station HYPO in Pearl.
My stories are sincere, but were never intended to be documentary history. I always liked to get to the loopy aspects of history- like, what was the party like at the quarters of chief code-breaker Joe Rochefort after the amazing results of the battle of Midway became known? (Answer: It was a good one).
Elliot Carlson is a professional historian who was working on his extraordinary biography of Rochefort through the same period, and detailed the scandalous story of Joe’s removal from command of HYPO by ankle-biting careerist hacks in the moment of his greatest triumph.
There is still a lot of emotion in all this. I know a pompous jackass here in town who was going around trying to discredit the story of how Joe’s band of Japanese linguists and cryptologists identified the target of the attack on Midway.
As you may recall, ENS Mac Showers was sitting at his desk in the Dungeon when Jasper Holmes outlined his scheme to tell the Commander at Midway (by way of secure submarine cable) to report by unencrypted radio that the fresh water plant on the coral atoll was malfunctioning. Holmes said that when the Japanese copied the radio transmission, it might reveal the identity of the target for the coming attack, and permit decisive action by the American Fleet.
Joe Rochefort liked the idea, and it worked. Within a few days, an encrypted Japanese message was de-coded that revealed the target- “AF”- was having fresh water problems.
It wasn’t perfect intelligence, but that is about as good as it gets in the world of COMINT. Joe was wary of the testy relations he had with the radio intelligence people back in Washington. He didn’t want the conclusion of the elegant subterfuge to be compromised by suspicion of who figured it out. So he provided the information to the Fleet Radio Unit in Melbourne, Australia, (FRUMEL) to have them report it.
Joe had a sign behind his desk that read: “There is no limit to what you can do, so long as you don’t care who gets the credit.” And so, sixty years after the fight, people were still fighting about stealing credit for what Jasper and Joe did in the basement of the 14th Naval District.
With things like that going on, Elliot relied heavily on Mac’s razor-sharp recollections to keep things straight. We are still attempting to get Mac’s 26-hour oral history transcribed and declassified- money and personnel bandwidth has been a challenge but we continue to press.
Elliot’s interviews with Mac were conducted in a much more focused manner than the ones I was doing, but they were complementary in nature.
I have asserted that the real villain in all this was Admiral Richmond Kelly “Terrible” Turner, who had been Chief of War Plans at Main Navy before the war had been instrumental in denying Hawaii access to the high-level Japanese Diplomatic messages in the Purple intelligence stream. That, and the famous Bomb Plot message are described In “Joe Rochefort’s War.”
The Bomb Plot message is presented on page 154 and onward in the book. The question from the filmmaker was about exactly that. I wrote him back that “Arlington Hall Station (across from where I now live) was where the Army conducted its code-breaking. Their charter- and part of the division of labor with Navy- was to attack the Japanese high-level diplomatic code (Purple) as well as less important cypher systems used by the Japanese diplomatic corps.”
HYPO’s mission was only to track Japanese Naval ships. The Bomb Plot message was in a different cypher system than Purple, known as “J-19,” and was considered a secondary priority to breaking Purple traffic. The message had originally been copied on 24 September at the Army intercept site at Fort Shafter on Oahu. They lacked translators and machine support at Monitoring Station-5 (MS-5), and so the cable in question was shipped back to Washington for processing.
According to Elliot, the message was eventually deciphered a few weeks later and circulated to the Army and Navy Radio Intelligence brass. They determined the request for detailed anchorage positions was routine and the message was then filed away without action.
It did not come to light until the Pearl Harbor inquiries were held- the first in the wake of the attack, and the second, more elaborate one, after the war was over and the sense of urgency slightly less.
Later, when the existence of the messages were revealed, Rochefort himself was not confidant that he would have recognized the Bomb Plot message as significant. He remarked that he might have just chalked it up to the obsessive nature of Japanese collection philosophy.
That was emphatically not true for Admiral Husband Kimmel and Lt. Gen. Short were, since they had already been railroaded and scapegoated. Both were back in Washington before the existence of the Bomb Plot message was revealed to either. Eddie Layton would probably have been the one to bring it to Kimmel as his Fleet Intelligence Officer, but it never made it back to Hawaii.
Nor did the high level Japanese diplomatic traffic transmitted in the Purple system. Richmond Kelly Turner made sure those messages did not get to Admiral Kimmel- including the ones that directed Japanese diplomatic staff to have things wrapped up by the end of November 1941. The Kido Butai, the IJN Main Body, sortied for Pearl on the 26th of that month.
At the dawn of the age of machine encryption, special machines had been constructed to assist the laborious process of breaking the contents of the messages- there are some great stories to tell about black-bag jobs and the like conducted by Naval Intelligence to enable the penetration of the codes. Station CAST in the Philippines had one. Station NEGAT in Washington had one.
The one intended for Pearl was in Bletchley Park in the UK. There is a story about that, too, and maybe we will get back to Beach Gradients one of these mornings soon.
But if anyone tells you that Joe Rochefort was wrong, or that the guys in Australia had anything to do with Jasper Holmes and his great idea, just tell them they are pompous partisan windbags.
Oh, and it is good to have friends. Thanks to that, I can give you a look at two of the Great Americans who labored in The Dungeon in the basement of the 11th Naval District at Pearl Harbor:
Copyright 2017 Vic Socotra