Several actions by FDR, General George Marshall, Admiral Harold Stark (CNO), Secretary of State Cordell Hull are obvious giveaways that they knew Pearl Harbor would be attacked and that they did not want Admiral Kimmel and General Short in Hawaii to know about the attack. A few examples:
-- Incredibly, FDR, Marshall, and Stark withheld the bomb plot messages from Kimmel and Short. If Kimmel and Short had seen those messages, they would have easily recognized that Pearl Harbor was being targeted for an air attack. MacArthur’s intel officers were getting the messages and readily recognized they indicated preparation for an air attack, and they assumed, naturally enough, that Kimmel and Short were also getting the messages.
Not only did Kimmel and Short not receive the bomb plot messages, they were not even told of their existence. The key turning point in the Navy Court of Inquiry (NCI) in 1944 came when Kimmel became aware of the messages (thanks to Lt. Cmdr. Lawrence Safford). The NCI members were stunned that Kimmel had not been given a single one of the messages.
By the way, FDR, Marshall, and Stark fought tooth and nail to keep the bomb plot messages from being released to the NCI, but they had to back down when the NCI demanded to see them.
-- On the morning of December 7, after the 14-part Japanese cable and its instruction messages had been decoded, everyone who read them knew they meant war. No one denies this. Yet, FDR did not use any of the options he had to immediately contact Kimmel, nor did Marshall, nor did Stark. They all had the means (two radio phone systems) to contact Kimmel and Short within 15-20 minutes.
Instead, Marshall sent a vague message in the form of a routine telegram. He could have at least sent a priority telegram and flagged it as urgent to expedite its transmission, but he chose to send it as a regular telegram with no importance indicator. No FDR apologist has yet offered a rational, credible explanation for Marshall’s astonishing failure to use his scrambler phone to contact the commanders in Hawaii, and his failure to at least send his telegram as a priority telegram marked as urgent.
-- In 1963, Congressman Martin Dies, chairman of the House Un-American Activities Committee during the Roosevelt era, revealed in his memoir that before the Pearl Harbor attack, his committee, in the course of investigating Japanese espionage, obtained a Japanese military map that clearly indicated a plan to attack Pearl Harbor. Dies, who was a Democrat, contacted Secretary of State Cordell Hull and told him about the map. Hull asked him to please keep quiet about it due to the "extremely delicate" diplomatic situation and to let President Roosevelt handle it. Dies also reported that representatives from the Army, the Navy, and the State Department examined the map. Dies expressed his frustration that this information was not acted upon:
I have never been able to understand why our government did not take the necessary precautions to protect our fleet from destruction after our committee had furnished such precise information on the proposed attack. (Martin Dies Story, p. 165)
Dies' account received corroboration in 1983 when retired journalist and former New Deal official Joseph Leib disclosed that seven days before the attack, Secretary of State Hull, who was a good friend of his, told him that FDR and certain other senior officials knew from intercepted Japanese messages that Japan was going to attack Pearl Harbor, and that FDR was going to allow the attack in order to get America into the war. Leib added that Hull also noted that FBI Director J. Edgar Hoover was fully aware of this information, as fact that Col. Carlton Ketchum confirmed.
Many more examples could be cited. I discuss the bomb plot messages and Marshall’s failure to warn Kimmel and Short in a timely manner on December 7 in
Six Myths of the Traditional Pearl Harbor Story.