Pearl Harbor Treachery?

I’ve heard and read that FDR had fore-knowledge of the attack on Pearl Harbor because we had broken the Japanese codes. He purposely held back warning the commanders at Pearl because he wanted to have an enraged US public motivated to allow and demand entry into WWII.
There’s little doubt that Churchill knew about the attack and he and FDR were pen pals.
Is there any definitive proof one way or the other?


http://www.netzone.com/~arjoy/pearl.htm

I think the current concensus amoung historians is the the government knew that the Japanese were planning to attack. They just didn’t know the “where” and the “when” of it. Pearl Harbor and 12/7/41 were pretty low on the Pentagon’s list of probable attacks.

IF (and it’s a big IF) FDR did suppress knowledge of an attack on Hawaii it was to protect the secret of American success at decoding Japanese radio messages, NOT to better facilitate a rightious war.

Papabear is right. Though the U.S. knew that something was up, there were questions of interpretation.

Most analysts of the events forget the fact that, at the time, no one knew the future. Even granted an unabiguous message, people have to decide if this is the real thing (maybe they misread the code, for instance) and often hesitate before taking action. This is just the normal way people react. Since no one knows the future, what seems a matter of urgency to us does not necessarily seem that way at the time.

And, no matter what the motivation for the hesitation of the people reading the message, there is no evidence Roosevelt knew anything about it prior to the attack.


www.sff.net/people/rothman

Regarding the possibility U.S. (or other armed forces) intercepted coded Japanese messages from the task force on its way to Pearl - The U.S. and Great Britain had broken the Japanese “Red” diplomatic code way back in the early 1930’s and were reading their messages with impunity.

The U.S. and G.B. were also well on the way to breaking the Japanese “Purple” wartime military code, thanks to the Japanese’ idiotic habit of beginning many messages with the same string of salutations, and their unfortunate blunder of transmitting a few messages in Red followed by the same message in Purple. (Both codes were produced on a variation of the old “Enigma” machine which was also used by the Germans, that’s a whole 'nother story).

However, the Japanese task force on its way to Pearl Harbor maintained strict radio silence, period. There were no intercepts because there was no radio traffic.

Conspiracy theories have never been hindered by a lack of evidence and the Pearl Harbor theories are no exception.

There is an excellent archive of documents on the Pearl Harbor attack and the subsequent Congressional investigation here:
http://metalab.unc.edu/pha/

[[The U.S. and G.B. were also well on the way to breaking the Japanese “Purple” wartime military code, thanks to the Japanese’ idiotic habit of beginning many messages with the same string of salutations, and their unfortunate blunder of transmitting a few messages in Red followed by the same message in Purple. (Both codes were produced on a variation of the old “Enigma” machine which was also used by the Germans, that’s a whole 'nother story).]]

A couple of quibbles here: while the Japanese diplomatic codes provided a lot of useful intelligence, it was the Japanese Naval codes, specifically JN-25 A and B, that yielded the best intelligence before and during the war.

The U.S. and Britain did arrange to share signal intercepts and decryptions and did divide responsibilities with Britain concentrating on German codes and the U.S. focusing on Japanese codes. I recall that these arrangements were made prior to December 7, 1941. About the only thing Britain contributed to American efforts was a listening station in Hong Kong.

The Japanese code machines were of entirely Japanese design and owe nothing to German Enigma technology. In many ways, the Japanese encryption devices were more sophisticated than Enigma, being entirely electrical devices rather electro-mechanical devices as Enigma was. Had the Japanese been more prudent in their communication discipline, the Japanese codes would have been much more difficult to crack than the German codes.

John Prados’s “Combined Fleet Decoded” is an excellent study of U.S. intelligence efforts against Japan and their effect on the war.

Andrew Warinner

While the subject has wandered a bit, here’s another piece of WWII cryptographic trivia. I’ve read that the one Axis nation that theoretical cryptographic security was Italy; the allies never were able to systematically break any Italian codes. But this didn’t really help the Italians. Most Italian military operations were conducted jointly with Germany and Germany always insisted on using all German codes because they believed they were more secure. As others have posted, the German Enigma codes were in fact routinely broken by Britain.

Roosevelt-haters and conspiract theorists have long insisted that FDR “knew” an attack at Pearl Harbor was imminent, and clammed up, because he WANTED a provocation that would lead us into war.

Never mind how absurdly X-filish the theory sounds. Assume for a minute that FDR was really sinister enough to do that.

The attack at Pearl Harbor was a DISASTER for America, and could have been far worse! Our ability to wage war against the Japanese was seriously hampered, and if the planned second wave of attacks had come, we might have been rendered utterly unable top fight the Japanese at all, for YEARS!

It’s quite likely that FDR was hoping for SOME kind of provocation or skirmish (a “Tonkin Gulf Incident” of sorts) to give him an excuse top enter the war. But there is NO WAY he’d have sat tight and done nothing if he’d known that an attack on Pearl Harbor (especially an attack of that magnitude) was coming.

Sorry right-wing loonies and X-file freaks: you’ll have to find some OTHER reason to hate FDR and the US Government.

…not to mention that by contemporary naval thinking, we should have lost the war at Pearl Harbor. Who knew that submarines and aircraft carriers (which weren’t in port that day) would be the key?


John W. Kennedy
“Compact is becoming contract; man only earns and pays.”
– Charles Williams

Another point against the conspiracy theory is that the Japanese meant to declare war against the U.S. in the hours before the attack, and only a logistic problem prevented that from happening. If FDR had known the location of the attack, surely they would have known about the war declaration. Wouldn’t he have been able to convince America to go to war against a declared enemy even if we had been able to repulse their attack?

And even if FDR wanted into a war, a war with Japan was not the one he would have wanted, but rather a war with Germany to help Britain. Germany was not compelled by treaty to come to the aid of Japan if Japan was the agressor, so FDR suppressing knowledge of a Japanese attack would not have guaranteed a war with Germany. The fact that Hitler declared war on the US a few days later, without having first consulted with anybody in his government, is more a testament to Hitler’s idiocy than any imagined conspiracy on FDR’s part.

Racism could have been a factor. Assume (as someone suggested) that FDR et al knew that the Japanese were planning some sort of attack, but did not know where or when it would occur. I remember reading that one theory is that it was simply assumed that whatever attack was mounted just naturally wouldn’t amount to much. They just didn’t belive that this non-white nation could be any real threat.

Found RealityChuck’s comments on human nature somewhat amusing, in the context of a wartime situation. He writes as if a decoding an “unamibuous message” would be an isolated incident, which could prompt one of only two actions: 1) we act on it; 2) we ignore it. and human nature being what it is, we of course ignore it.

Yes, people at the time could not see the future, but that does not mean they would have had no sense of urgency. There was a war going on, and there was an increasinlyg tense situation between the U.S. and Japan that was leading to war. Under these circumstances, there should have been ample cause for an urgent response to any indication that the expected war with Japan was, in fact, about to commence.

By the way,none of this is meant to endorse the conspiracy theories about Roosevelt. The info might have been there for military intelligence to predict/guess the attack, and we might blame the people responsible for not coming to this conclusion fast enough, but I don’t think anyone knew the specific facts and chose to ignore them for political reasons that are at best dubious. (An attempted Japanese sneak attack was enough to prompt U.S. entry into the war; a successful Japanese sneak attack was hardly necessary.)

My History Professor in college dismissed the theories of a conspiracy whole heartedly. He said that Pearl Harbor had been on red alert for weeks prior to the attack, so they realized something might happen. But, as things go, when you are on red alert for such a long period of time red alert isn’t quite as urgent.
I don’t have a cite for this story, it was part of a lecture. SO, if you need to know where he got his info you will have to ask Professor Leo Ribuffo… Great professor, by the by.

pat

“Racism could have been a factor. Assume (as someone suggested) that FDR et al knew that the Japanese were planning some sort of attack, but did not know where or when it
would occur. I remember reading that one theory is that it was simply assumed that
whatever attack was mounted just naturally wouldn’t amount to much. They just didn’t believe that this non-white nation could be any real threat.”

To quote from one of the various official reports on the Pearl Harbor attack:

"General Billy Mitchell forecast an assault by carrier launched aircraft on Pearl Harbor after his 1924 Asian tour.[50] The US Navy had fleet exercises and war games involving air strikes on Pearl Harbor in the 1930s.[51]

[50] See generally, Russell F. Weigley, ‘History of the United States Army’, New York, 1967, pp. 412-414.
[51] See generally, Hawaiian Department, ‘Joint Army and Navy Maneuvers, Raid Phase, Jan. 29-31, 1933’"

From various and sundry sources:
*6/4/40: U.S. embargo on export of machine tools to Japan.
*10/27/40: U.S. embargo on export of scrap iron to Japan.
*3/27/41: Congress passed the Pacific Bases Reinforcement Bill, appropriating $1.5 billion. (That’s 1941 money!)
*4/25/41: FDR announces the adoption of a coastal patrol system covering the entire coast line of the United States.
*7/26/41: Japanese assets frozen by United States and Britain.
*8/1/41: U.S. embargo on aviation gasoline export to Japan.

And the whole reason the Pacific Fleet was at Pearl Harbor in the first place was to be forward-deployed for rapid response to a Japanese attack, which was expected to fall upon the Phillipines and other U.S. possessions in the Pacific as well as upon British, French, and Dutch colonies.

None of the above sound like the majority of the U.S. government or military officials weren’t taking Japan seriously because it is a “non-white nation.” About the only “basis” for such a conclusion is the presumption many people make that anyone who is of an earlier generation than their own is, ipso facto, racist.

“My History Professor in college dismissed the theories of a conspiracy whole heartedly. He said that Pearl Harbor had been on red alert for weeks prior to the attack, so they realized something might happen. But, as things go, when you are on red alert for such a long period of time red alert isn’t quite as urgent.”

There is some truth to this but there was no formalized system of alerts, that is a Cold War invention.

Admiral Kimmel and General Short were well informed of the deteriorating political situation as well as Japanese military moves in the South Pacific. In particular, Kimmel received the following message on November 27, 1941:

THIS DESPATCH IS TO BE CONSIDERED A WAR WARNING. NEGOTIATIONS WITH JAPAN LOOKING TOWARD STABILIZATION OF CONDITIONS IN THE PACIFIC HAVE CEASED AND AN AGGRESSIVE MOVE BY JAPAN IS EXPECTED WITHIN THE NEXT FEW
DAYS. THE NUMBER AND EQUIPMENT OF JAPANESE TROOPS AND THE ORGANIZATION OF NAVAL TASK FORCES INDICATES AN AMPHIBIOUS EXPEDITION AGAINST EITHER THE PHILIPPINES THAI OR KRA PENINSULA OR POSSIBLY BORNEO. EXECUTE AN
APPROPRIATE DEFENSIVE DEPLOYMENT PREPARATORY TO CARRYING OUT THE TASKS ASSIGNED IN WPL46
. INFORM DISTRICT AND ARMY AUTHORITIES. A SIMILAR WARNING IS BEING SENT BY WAR DEPARTMENT. SPENAVO [99] INFORM BRITISH.
CONTINENTAL DISTRICTS GUAM SAMOA DIRECTED TAKE APPROPRIATE MEASURES AGAINST SABOTAGE.

So Pearl Harbor did have warning that war was imminent shortly before December 7 but the message also names the Philippines and the Southeast Asia as being under the immediate threat of attack. The message also warns against sabotage.

On November 28, the War Department sent Kimmel the following message:

ARMY HAS SENT FOLLOWING TO COMMANDER WESTERN DEFENSE COMMAND "NEGOTIATIONS WITH JAPAN APPEAR TO BE TERMINATED TO ALL PRACTICAL
PURPOSES WITH ONLY THE BAREST POSSIBILITIES THAT THE JAPANESE GOVERNMENT MIGHT COME BACK AND OFFER TO CONTINUE. JAPANESE FUTURE ACTION
UNPREDICTABLE BUT HOSTILE ACTION POSSIBLE AT ANY MOMENT. IF HOSTILITIES CANNOT REPEAT NOT BE AVOIDED THE UNITED STATES DESIRES THAT JAPAN COMMIT THE FIRST OVERT ACT. THIS POLICY SHOULD NOT REPEAT NOT BE CONSTRUED AS RESTRICTING YOU TO A COURSE OF ACTION THAT MIGHT JEOPARDIZE YOUR DEFENSE. PRIOR TO HOSTILE JAPANESE ACTION YOU ARE DIRECTED TO UNDERTAKE St-CH RECONNAISSANCE AND OTHER MEASURES AS YOU DEEM NECESSARY BUT THESE MEASURES SHOULD BE CARRIED OUT SO AS NOT REPEAT NOT TO ALARM CIVIL POPULATION- OR DISCLOSE INTENT.

So the Pearl Harbor commanders had another warning, though not without ambiguity and certainly not one that directed them to take specific precautions.

At this point I could speculate about ‘what-ifs,’ but given the course of the war over the next few months it is hard to see how a more alert defense of Pearl Harbor would have made much of a difference.

Andrew Warinner

My question is a bit different: why was the US Army Air Force cought completely by surprise in the Philippines-most of the planes were caught on the ground by the Japanese. If anyone should have been on alert, it should have been US forces in the Philippines (close to Japan, logical first target).
I think the theory (that Roosevelt allowed the Pearl harbor Disaster) grew up because of the strange subsequent behavior of Admiral Kimmel and General Short-both men were relegated to desk jobs, and never commented publicly on any of this thereafter.

But even under those circumstances, there are always questions if you don’t know the outcome. Was the message genuine? Was it accurately translated? Was it some sort of test by the Japanese? Were they trying to get us to attack their ships and claim the U.S. was the aggressor?

And the person decoding the message can’t just call up the president. He goes to his superior, who has to make a determination, using all the factors of the first guy plus considering whether the person who came to him tends to overreact to or misinterpret data. In turn, that officer probably doesn’t have a direct line to the president and has to send it along to someone else, (who may be out of the office at the time) and who has to make all the same determinations and a few more.

There are plenty of ways that you can drop the ball on this sort of thing, especially early on a Sunday morning when your top people aren’t working. Since the people involved have no knowledge of how events will transpire, their actions, even in a tense situation (which can make people more cautious – what if the message were fake and the U.S. was drawn into firing the first shot?*), may not be what we in hindsight can see was the obvious things to do.

*Yes, I know that the U.S. fired the first shot at Pearl Harbor, sinking a Japanese sub a few hours before the main attack. Of course, that was overshadowed by the intensity of the Japanese attack.


www.sff.net/people/rothman

To answer gene’s question about the Phillipines:

Gen. MacArthur was a retard!

If ever there was an example of erratic military judgement in the history of warfare, Douglas MacArthur is it. On Dec. 7 the Gen. had all the planes bunched together to protect them from sabotuers, hence making them a nice big juicy target for Japanese bombers.

“If ever there was an example of erratic military judgement in the history of warfare, Douglas MacArthur is it. On Dec. 7 the Gen. had all the planes bunched together to protect them from sabotuers, hence making them a nice big juicy target for Japanese bombers.”

I think you are confusing it with General Short and the defensive posture of the airfields in Pearl Harbor.

The facts of the matter are this: some nine hours after the attack on Pearl Harbor, Japanese air raids on the Philippines destroyed most of the American planes there on the ground. An official U.S. Army mongraph says:

The Japanese success in the Philippines hours after the attack on Pearl Harbor has sparked controversy with much finger-pointing that has endured to this day. General Brereton later wrote that he repeatedly sought permission before the attack to launch his B-17s against the Japanese aircraft in Formosa, but General Sutherland denied his requests and also denied him access to MacArthur. MacArthur later insisted that he was unaware of Brereton’s request, adding that such a move would have been ill conceived anyway because USAFFE lacked intelligence concerning likely targets. For his part Sutherland claimed that he had ordered Brereton to transfer his bombers away from Clark Field to the relative safety of Mindanao to the south; Brereton countered that he could not have fully complied with the order because of the impending arrival of a new bombardment group from Hawaii. Officers stationed at Clark Field later disagreed about whether their installation had even received warning of the approaching aircraft as the attack was about to start.
http://metalab.unc.edu/hyperwar/USA/USA-C-Philippines.html

While there is controversy why the bombers on the ground, why the fighters were on the ground is mostly due to Japanese luck. The Japanese had planned to attack the Philippines earlier but weather over Formosa delayed their planes from taking off. American fighters were scrambled when word was received of Pearl Harbor but had to return to their bases to be refueled, when, as luck would have it, the delayed Japanese attacks arrived.

Of course this does not explain why MacArthur was able to survive the numerous military disasters in the Philippines and was not unceremoniously booted as was Kimmel and Short were.

Andrew Warinner