Did FDR Know About the Pearl Harbor Attack Ahead of Time? Revisiting an Old Conspiracy Theory

Pearl Harbor attack | Date, History, Map, Casualties, Timeline, & Facts |  Britannica

December 7th, 2021 marks the 80th anniversary of the Japanese attack on Pearl Harbor. Although after the attack, American patriotism skyrocketed and the nation unified to win World War II, after the war ended and the dust had settled questions were being asked about how we got into war. The traditional story, as we know, is that the Japanese were aggressive and that their ambitions would have eventually resulted in conflict with the United States regardless and that Roosevelt was trying to pressure Japan into backing off rather than getting into war. In 1948, President Harry S. Truman declassified all documents surrounding Pearl Harbor, and out came the revisionist works. Roosevelt foe John T. Flynn then wrote The Roosevelt Myth, which accused the late president of getting the United States into war for economic recovery. Revisionist historians such as Charles A. Beard, Charles Callan Tansill, and Harry Elmer Barnes were also promoting rethinking the causes of Pearl Harbor. Tansill alleged in Back Door to War (1953) that crucial intelligence was deliberately withheld from Hawaii and Barnes claimed in Perpetual War for Perpetual Peace (1953) that the Roosevelt Administration had engaged in multiple cover-ups surrounding Pearl Harbor (Johnson, 57-58). A more compelling work was in 1954, in which Rear Admiral Robert Theobald, who was present at Pearl Harbor, wrote The Final Secret of Pearl Harbor: The Washington Contribution to the Japanese Attack, in which he accused FDR of suppressing intelligence in the name of provoking an attack. More recently, author Robert Stinnett caused a stir when in his book, Day of Deceit (1999), he argued that based on declassified documents FDR knew the attack on Pearl Harbor would occur ahead of time and withheld vital intelligence to Hawaii. What his book contributed most was that the story about radio silence from the Japanese in the weeks preceding the attack was false, and that it was possible for Hawaii to have been warned of an impending attack through the deciphering of the Japanese code, which the Americans had cracked by that time (Bernstein). Whether such deciphering was made in a timely manner or had even made its way to Roosevelt is unknown. Since World War II, there have been numerous declassified documents and there are some things we now know based on them.

What We Know Now

FDR’s Day of Infamy Speech

FDR and Administration officials expected a Japanese attack on December 6th or 7th, but it has not been proven they knew where it would happen.

There was a naval intelligence report sent to FDR three days before the attack on Pearl Harbor that the Japanese military and spy network was focusing on Hawaii (Bedard). This does not necessarily imply knowledge of a coming attack on Hawaii.

Rear Admiral Robert Theobald wrote on November 25, 1941, “The President at once brought up the relations with the Japanese. Mr. Hull said that the Japanese were poised for the attack – that they might attack at any time. The President said that the Japanese were notorious for making an attack without warning and stated that we might be attacked, say next Monday, for example. One problem troubled us very much. If you know your enemy is going to strike you, it is not usually wise to wait until he gets the jump on you by taking the initiative. In spite of the risk involved, however, in letting the Japanese fire the first shot, we realized that in order to have the full support of the American people it was desirable that the Japanese be the ones to do it so that there should remain no doubt in anyone’s mind as to who were the aggressors” (Hurst, 76-77).

The greatest problem with the Pearl Harbor theory, and in fact one that unless you pretty much accept that Roosevelt is stupid and evil destroys the idea that he knew where the attack would happen, is that so much of the fleet was stationed at Pearl Harbor. If his aim was simply to goad Japan to attack, why take such great damages? Would he not want to be in a better position to win once at war? Roosevelt and military leadership believed that the presence at Pearl Harbor served as a deterrent rather than a target, thinking that American territories closer to Japan (the Philippines and Guam) would be subject to such an attack (Dallek). However, that doesn’t mean there was no intent for war or even no conspiracy.

The Real Conspiracy

Harry Dexter White (left)

President Roosevelt had taken several actions in the months preceding Pearl Harbor that had escalated tensions between Japan and the United States. This included freezing all Japanese assets in the United States on July 26th in response to Japan’s occupation of South Indochina (which had been approved by Vichy France) that had been for the purpose of cutting off oil imports to China, the oil and gas export embargo on August 1st that severely compromised Japan’s oil and gas supply, and finally the November 26th ultimatum. It could be argued that for the former two responses that Roosevelt was either trying to apply economic pressure for Japan to pull back their war machine, or to push the US closer to war. The ultimatum, however, was an uncompromising list of demands in response to a Japanese diplomatic effort to ease tensions between the two nations. FDR had approved this version over a more diplomatic version after he learned of a Japanese expeditionary force heading to Indochina, and the key demands of the final version had been drafted by none other than Soviet agent Harry Dexter White, and it was after this that Japan’s government decided to attack Pearl Harbor (Steil, 55-56). This was a part of a Soviet operation called “Operation Snow”, the purpose of which was to get the US and Japan into war with each other. While FDR’s intentions here are as I noted debatable, the real conspiracy that put the US to war with Japan was on the part of the Soviets eager to avoid the possibility of being attacked by Japan. That’s correct, I mean to say that the immediate cause of the Pearl Harbor attack was the product of a Communist conspiracy. While it is entirely possible that the US and Japan would have ended up going to war anyway, the trigger was, in effect, pulled by the Kremlin.


Bedard, P. (2011, November 29). Declassified Memo Hinted of 1941 Hawaii Attack. US News.

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Bernstein, R. (1999, December 15). ‘Day of Deceit’: On Dec. 7, Did We Know We Knew? The New York Times.

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Dallek, R. Pearl Harbor and the Back Door to War Theory. Encyclopedia Britannica.

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Hurst, D. (2004). America’s National Interest: The Politics of Deceit. Florida State University.

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Johnson, T. (1987). What Every Cryptologist Should Know about Pearl Harbor. Cryptologic Quarterly, 6(2)

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No, FDR Did Not Know the Japanese Were Going to Bomb Pearl Harbor. (2016, December 6). National Public Radio.

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Steil, B. (2013). The battle of Bretton Woods: John Maynard Keynes, Harry Dexter White, and the making of a new world order. Princeton, NJ: Princeton University Press.

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