Pearl Harbor at 70: Controversy and Conspiracy?

For the last seventy years, a debate has raged among historians and authors about the Japanese attack on Pearl Harbor on December 7, 1941. Was the U.S. caught off guard? Or, was the attack expected? And even more inflammatory, was advance knowledge of the attack hidden from the military and the public by Franklin Roosevelt?

At least two dozen books have been written on the subject. Who knew what and when did they know it? Many people have claimed that a conspiracy was in place to hide the truth in order to support a larger objective; assuring U.S. entry into World War II.

Between 1941 and 1995, there have been ten U.S. Government inquiries into this controversy. Many of the important records were classified during the early investigations, but with the Freedom of Information Act passage, new evidence has now become known. Some of it seems to support the idea of a conspiracy and some does not.

The following is an attempt to review and summarize the major issues that may still be unresolved.

Controversies over the events before, during, and after December 7, 1941, can be separated into two distinct groups of issues.

FIRST. Did Franklin Roosevelt and his Administration attempt to pressure Japan into accepting concessions that would limit their economy and their ambitions of power? Yes, possibly. And, knowing that Japan could not accept this, would they take military action against the U.S. and Britain in Asia? Yes, possibly. And would that action bring the U.S. into the war against Germany, due to its military alliance with Japan? Yes, possibly.

SECOND. Were the controversial events surrounding the Japanese attack on Pearl Harbor facilitated, or at least allowed, by the U.S. Government? Were lives, property, and materials sacrificed to provoke a war? That is left up to you to decide.

I. Provocations to Push Japan Into War

Accusations of conspiracy were directed toward the Roosevelt administration in that they allegedly provoked the Imperial Japanese Navy to attack Pearl Harbor and bring the U.S. into WWII, by popular public support.

But you first need to know the background of the situation.

Economic Strangulation

For three years before the Pearl Harbor attack, the Americans and the British secretly explored the possibility of war with Japan. In 1940, Japan agreed to withdraw from China; they also offered to pull out of the new Trilateral Treaty, their military alliance with Germany and Italy. Japan made these overtures in exchange for being allowed to expand their economic sphere without constrain by America, Britain, and other European colonial powers. These offers were turned down.

Later that year, Roosevelt began a form of economic pressure by embargoing strategic goods, especially iron and steel to Japan. The next year, oil shipments were restricted and Japanese funds in U.S. banks were frozen.

Caught in an economic vise, Japan began to hint at military action if no compromise was reached by the autumn of 1941. In November, Japan offered to negotiate peace with China and to withdraw its troops from Indochina if granted commercial stabilization. All the while they were moving military forces toward American, British, and Dutch colonies, in case their offer was rejected.

The United States and Britain found the Japanese offer “utterly unacceptable.”

But neither Winston Churchill nor Franklin Roosevelt wanted war with Japan at that time. Britain was locked in combat with Nazi Germany and couldn’t sustain a second major war on its own in another hemisphere. America was not in a position to enter into war at all. They needed more time to prepare.

Ten days prior to the Pearl Harbor attack (11-27-41), Gen. George C. Marshall had prepared a memorandum for FDR which read in part, “The most essential thing now, from the United States viewpoint, is to gain time . . . Precipitance of military action on our part should be avoided.”

Was the McCollum Memo a blueprint for provoking the Japanese to attack.

A year before the Pearl Harbor attack, the Office of Naval Intelligence (ONI) submitted a memo which conspiracy theorists point to as a plan of action to compel the Japanese to attack some U.S. installation. It was considered the famous “smoking gun.” In reality, according to the author Arthur McCollum, it was meant only as an outline of the East Asian situation and included recommendations to deter and contain Japan while the U.S. could better prepare for any future conflict, if it occurred. After the war, McCollum’s own testimony refuted any attempt on his part to advocate provoking Japan.

Additionally, McCollum was never in contact with FDR, and there is no indication that the President ever saw the memo.

Would Americans support a war with Japan?

People pointing to a conspiracy believe that without a Japanese attack, Americans would have never supported a war with Japan. This was very far from the truth however. Isolationism and anti-war sentiment was quickly fading during the summer of 1941. Over 67% of the American public felt that the U.S. should risk war with Japan rather than allow it to grow more dominant (70% felt the same way towards Nazi Germany).

In all likelihood Roosevelt would have had little difficulty getting a declaration of war against Japan after all the attempts at negotiation had failed in November of 1941.

To believe that FDR was willing to sacrifice the most important military base in the Pacific, most of the U.S. Pacific fleet, and thousands of American casualties in order to gain support for a declaration of war that already had a two-to-one public approval rating doesn’t make any sense at all. The votes in Congress were equally easy to obtain.

Did Roosevelt know that there would be an attack on American or British possessions in the Pacific? Yes, probably. Did he know where? No.

II. Was there advance knowledge of Japan’s attack and a conspiracy to keep this a secret?

The following events are all claimed to be indications of a conspiracy by the U.S. Government to allow a Japanese attack on America.

Japanese secret codes had already been deciphered; we knew what they planned to do.

It is true that American intelligence had broken some Japanese codes, and had perceived of a warning of an attack to take place, somewhere. They also had information the British cracked and passed on.

It’s important to realize that in Japan prior to the war, there was a rise to power of a group of generals and admirals who were challenging the civilian government. They were the new “Shoguns.” This new power structure in Japan did not always inform its diplomats of planned operations, even in secret coded messages.

While the “diplomatic” code (called “Purple”) had been decoded, the “military” codes, including the Imperial Japanese Navy code, called JN-25, had NOT been cracked. The new version of JN-25 in use by Japan prior to Pearl Harbor was not decrypted until May of 1942. So the coded messages that the U.S. could intercept were the less significant diplomatic ones, not the crucial military ones.

It was discovered that the Japanese were going to deliver a specific message to the State Department on December 7^th and then destroy their cipher machine and all secret documents. It was clear that something was about to happen but no one could be sure where to expect a Japanese attack. There were a lot of more likely targets than Pearl Harbor. The best estimate was the Philippines, Thailand, or Borneo; and warnings were sent on to the forces in those regions.

Knowledge of an, as yet, undelivered Japanese Declaration of War was ignored by the Secretary of State.

U.S. Intelligence cryptographers discovered that the Japanese Ambassador to Washington was supposed to deliver a document to the Secretary of State. This was shortly before the attack was commenced on Pearl Harbor. The State Department was convinced that it was a Declaration of War. If a conspiracy to start a war against Japan existed, the interception of this secret communication to the Japanese Ambassador was all the justification needed.

The document was not a Declaration of War or a breaking off of diplomatic relations. It was just a restating of Japanese grievances against the U.S. The actual Declaration of War was not announced until after the Pearl Harbor attack.  

The Japanese “Kido Butai” (mobile strike force) was detected and monitored approaching Pearl Harbor but no action was taken.

The “Kido Butai” sailed from the Kurile Islands on October 26^th with 55 ships, including six carriers and 27 submarines. Its air strength consisted of 402 combat aircraft (fighters, torpedo bombers, and dive bombers).

Claims have been made that radio signals were detected by U.S. intelligence that confirmed an attack on Pearl Harbor. This is actually the most easily dismissed of all conspiracy theories. The Imperial Japanese Navy felt that secrecy was so critical to the success of the mission that radio silence would be strictly enforced.

In fact, the fleet’s radio operators were left behind in Japan to send fake communications indicating that the fleet was still in home waters. Every day false dispatches were broadcast and U.S. intelligence concluded that the Japanese fleet was still training in the Sea of Japan. American radiomen later swore that they recognized the distinctive pattern of the Japanese radio operators, which of course they did.

All radio transmitters on all ships were disabled (even the ones mounted in the aircraft). The fuses in the radio circuits and the keys to all radios were removed and impounded. The only communication allowed between the ships was by flags or blinking lights, as all ships were ordered to stay in a line of sight.

After the war, Japanese Naval officers insisted that there was no radio traffic emanating from their fleet at any time between leaving Japan and arriving near Hawaii on December 7^th. Per the custodians of the Freedom of Information Act requests, “The source documentation shows that not one single radio direction finder bearing, much less a location fix, was obtained on any Kido Butai unit or command during its transit from Saeki Bay, Kyushu to Hawaii.”

Some believe that the Matson passenger liner “Lurline,” in route from San Francisco to Hawaii, heard radio traffic which continued for several days and plotted the movement of a large group of surface ships heading eastward across the Pacific. The records of the Lurline have disappeared, however, and there was no Navy or Coast Guard report made. Matson radiomen later reported that the signal they were following eventually “bunched up” and stopped moving. The likely origin of the radio traffic they heard was commercial fishing vessels.

American forces on Hawaii were not properly prepared for hostilities.

The Japanese consulate in Honolulu had a staff of undercover intelligence officers reporting to the Imperial Japanese Navy. They had reported on U.S. Navy operations for years. The master spy, Takeo Yoshikawa, found the Pearl Harbor security so lax that he even inspected the fleet close up on the Navy’s own harbor tour boat. But even that was unnecessary. Anyone sitting on the accessible hills above the Harbor could observe and photograph everything.

The senior U.S. commanders in Hawaii were Admiral Husband E. Kimmel, of the Navy, and General Walter C. Short, of the Army. All Navy facilities and ships at Pearl Harbor were considered under the protection of the U.S. Army.

Two weeks prior to the attack, both Navy and Army commanders were sent warnings of possible war with Japan and ordered to make defensive adjustments and be on alert. These warnings never specifically mentioned Pearl Harbor, focusing on installations farther to the west.

Gen. Short was concerned mostly with possible sabotage, as it frequently preceded attacks. He ordered the AAF aircraft to be parked in close formation near the center of the airfield. This was appropriate for sabotage, but turned out to be a disaster in an air strike.

The most important radar installations were not yet integrated into the local command after a year of work, and no urgency was exhibited even after the warnings. Leisurely training continued as before. Anti-aircraft guns were in a low state of readiness as well with ammunition locked up far away from guns. Neither Army nor Navy aircraft were actively used for patrols. Many were undergoing routine maintenance and partially disassembled.

Rivalries between the services, especially between Kimmel and Short, made the situation worse. Even though Short was responsible for the security of the island, most intelligence information was sent to Kimmel. The Admiral did not keep General Short in the loop most of the time. Military men of the caliber of Kimmel and Short should have recognized the importance of the alerts, even though the chance of attack at Pearl Harbor was slight, but they didn’t. Later, both officers were considered for Court Marshal, but it was dropped due to security concerns.

Another factor was that Navy commanders at Pearl Harbor believed that the harbor was immune to torpedo attack because it was too shallow. Even though Naval Operations insisted that no harbor should be considered safe from air launched torpedoes. Additionally, anti-torpedo netting was not used around the ships because removing it would be time-consuming and slow the ships from leaving the harbor on short notice.

The Japanese decision to focus their attack as far to the east as Pearl Harbor and to use aircraft to disable the American fleet was so radical that needed analysis and preparation was not even considered.

While these decisions were regrettable, the local commanders could not be accused of being part of a high level conspiracy since alerts from Washington did not specifically designate Pearl Harbor as a prime target for attack.

Note: Douglas MacArthur, who had complete access to intelligence and the motivation to act, seeing Japanese forces in his region, was also unprepared for attack. Most of his aircraft were sitting on the ground when the Japanese attacked the day after Pearl Harbor.

US aircraft carriers were put to sea before the attack to keep them safe. 

Some people believe that the aircraft carriers stationed at Pearl Harbor were put out to sea because of a suspected Japanese attack. They feel that Roosevelt and the Navy Department knew that any future sea combat would be dominated by aircraft carriers and they wanted to keep the few available safe from any premature engagement. Conspiracists use this as proof that the U.S. Government knew the country would be attacked by Japan.

This is incorrect on two counts. First, few people at the time thought that the aircraft carriers would become the valuable weapons that they proved to be later in 1942 at the Battle of Midway. Most Naval leaders, the Japanese included, believed that battleships would do the real fighting. Carriers were classified as fleet scouting elements and relatively expendable.

Second, the two carriers that were assigned to Pearl Harbor were the Enterprise (pictured) and the Lexington (the third carrier, Saratoga, was in dry dock in Oregon). Both active carriers were on secret missions, planned in August of 1941, to deliver fighters to Wake and Midway Islands in a build-up of forces at those locations. These orders were never changed. The fighters they were transporting could not have flown those distances so they were being taken by ship. Both carriers were widely separated from each other (not allowing one to support the other) and they were lightly escorted; and they probably could not have been defended in a massive assault. If these were thought to be such valuable assets, they would not have been on this mission.

In fact, the Enterprise had delivered its cargo and was headed back to Pearl Harbor. It was only 200 miles west of Hawaii and was due to arrive at Pearl on December 6^th (the day before the attack). A storm delayed her arrival but she was close enough to send her aircraft ahead to Pearl Harbor as the attack was still in progress. Some of the Enterprise’s aircraft were shot down by “friendly fire.”

American commanders at Pearl Harbor were not alerted to imminent attack until December 7^th.

A Japanese attack was expected almost anywhere, except at Pearl Harbor. Since the Japanese were engaged in an invasion of Thailand, it seems unlikely that they would mount a second major campaign in the autumn of 1941. Even less likely was an air attack. Kimmel and Short had good reason to feel safe.

War became a certainty only about 12 hours before the attack when Japanese diplomats in Washington met with the State Department to refuse the latest political and economic demands of the U.S.

Pearl Harbor Navy and Army commanders did not receive urgent messages about impending war until the morning of the attack. Conspiracy theorists believe that this was an intentional delay to prevent the forces at Pearl Harbor from bracing for the attack.

General George Marshall had a message sent to all Pacific forces alerting them to imminent hostilities with Japan but atmospheric conditions prevented communication between Washington and Pearl Harbor. His message was sent via Western Union but did not arrive until the morning of December 7^th and was further delayed by the air raid itself.

If a conspiracy was in the works, why send a warning at all?

Local reports of enemy activity just before the air attack were ignored.

Technicians at the Opana Point radar site reported that a sizeable formation of aircraft were spotted approaching the island about an hour before they actually reached Pearl Harbor. They called the Fighter Information Center, which was new and not completely functional yet, to alert them. The officer in charge thought the formation was a flight of B-17’s due that day from the U.S. mainland and told the operators to forget the radar signal. Since the report went no higher than the on duty Lieutenant, it was unlikely that there was any conspiracy involved.

Some people point to an incident of military action just outside the harbor entrance that was not reported quickly to top command as proof that a conspiracy to allow the attack was in place. The USS Ward was on anti-submarine patrol near the harbor entrance when it sent a message that a submarine had been engaged and sunk. This was more than an hour before Japanese bombers arrived. The Sub Captain’s actual report was that a sub was encountered but not sunk. He asked land based communication to advise him as to his next action. Decoding his message and encoding a reply took time, during which the air attack had begun.

In Conclusion

The attack upon Pearl Harbor cost America 3,649 human casualties. The U.S. Pacific fleet was significantly damaged, and took nearly two years to recover. All eight of the Navy’s battleships in port were either sunk or damaged. The Army lost 335 of its 390 aircraft.

Four days later on December 11^th, Hitler declared war on the U.S. in support of his ally Japan, and America had entered the war in Europe as well.

Americans were shocked and horrified by the carnage at Pearl Harbor. And there was no longer any reason to hold onto our isolationist position. We were at war. The next four years saw a desperate struggle with the Empire of Japan play out from one island to the next. When it was over, there was a new world order. A Nuclear World.