The attack on Pearl Harbor (called Hawaii Operation or Operation AI by the Japanese Imperial General Headquarters (Operation Z in planning)and the Battle of Pearl Harbor, was a surprise military strike conducted by the Imperial Japanese Navy against the United States naval base at Pearl Harbor, Hawaii, on the morning of December 7, 1941 (December 8 in Japan). From the standpoint of the defenders, the attack commenced at 7:48 a.m. Hawaiian Time. The attack was intended as a preventive action in order to keep the U.S. Pacific Fleet from interfering with military actions the Empire of Japan was planning in Southeast Asia against overseas territories of the United Kingdom, the Netherlands, and the United States.
The base was attacked by 353 Japanese fighters, bombers and torpedo planes in two waves, launched from six aircraft carriers. All eight U.S. Navy battleships were damaged, with four being sunk. Two of these were later raised, and with the remaining four repaired, six battleships returned to service later in the war. The Japanese also sank or damaged three cruisers, three destroyers, an anti-aircraft training ship, and one minelayer. 188 U.S. aircraft were destroyed; 2,402 Americans were killed and 1,282 wounded. Important base installations such as the power station, shipyard, maintenance, and fuel and torpedo storage facilities, as well as the submarine piers and headquarters building (also home of the intelligence section) were not attacked. Japanese losses were light: 29 aircraft and five midget submarines lost, and 65 servicemen killed or wounded. One Japanese sailor was captured.
The attack came as a profound shock to the American people and led directly to the American entry into World War II in both the Pacific and European theaters. The following day (December 8), the United States declared war on Japan. Domestic support for non-interventionism, which had been strong, disappeared. Clandestine support of Britain (for example the Neutrality Patrol) was replaced by active alliance. Subsequent operations by the U.S. prompted Germany and Italy to declare war on the U.S. on December 11, which was reciprocated by the U.S. the same day.
There were numerous historical precedents for unannounced military action by Japan. However, the lack of any formal warning, particularly while negotiations were still apparently ongoing, led President Franklin D. Roosevelt to proclaim December 7, 1941, "a date which will live in infamy".
The Pearl Harbor advance-knowledge conspiracy theory is the idea that American officials had advance knowledge of Japan's December 7, 1941 attack on Pearl Harbor. Ever since the Japanese attack there has been debate as to how and why the United States had been caught off guard and how much and when American officials knew of Japanese plans for an attack.
Several writers, including journalist Robert Stinnett and former United States Navy Rear Admiral Robert A. Theobald, have argued that various parties high in the U.S. and British governments knew of the attack in advance and may even have let it happen or encouraged it in order to force America into war via the "back door." Evidence supporting this view is taken from quotations and source documents from the time and the release of newer materials.
Ten official U.S. inquiries
The U.S. government made nine official inquiries into the attack between 1941 and 1946, and a tenth in 1995. They included an inquiry by Secretary of the Navy Frank Knox (1941); the Roberts Commission (1941–42); the Hart Inquiry (1944); the Army Pearl Harbor Board (1944); the Naval Court of Inquiry (1944); the Hewitt investigation; the Clarke investigation; the Congressional Inquiry (1945–46); a top-secret inquiry by Secretary of War Henry L. Stimson, authorized by Congress and carried out by Henry Clausen (the Clausen Inquiry; 1946); and the Thurmond-Spence hearing, in April 1995, which produced the Dorn Report. The inquiries reported incompetence, underestimation, and misapprehension of Japanese capabilities and intentions; problems resulting from excessive secrecy about cryptography; division of responsibility between Army and Navy (and lack of consultation between them); and lack of adequate manpower for intelligence (analysis, collection, processing).
Investigators prior to Clausen did not have the security clearance necessary to receive the most sensitive information, Clausen claimed that, in spite of Secretary Stimson having given him a letter informing witnesses that he had the necessary clearances to require their cooperation, he was repeatedly lied to until he produced copies of top secret decrypts, thus proving he indeed had the proper clearance.
Stimson's report to Congress, based on Clausen's work, was limited due to secrecy concerns, largely about cryptography. A more complete account was not made publicly available until the mid-1980s, and not published until 1992. Reaction to the 1992 publication has varied. Some regard it as a valuable addition to understanding the events, while one historian noted Clausen did not speak to General Walter Short, Army commander at Pearl Harbor during the attack, and called Clausen's investigation "notoriously unreliable" in several aspects.
Roosevelt's desire for war with Germany
Theorists challenging the traditional view that Pearl Harbor was a surprise repeatedly note that Roosevelt wanted (though he did not say so officially) the U.S. to intervene in the war against Germany. A basic understanding of the political situation of 1941 precludes such an understanding as reasonable evidence Roosevelt invited, allowed, or even knew of the Pearl Harbor attack. Military historian and novelist Thomas Fleming argues that President Roosevelt, himself, had wished for Germany or Japan to strike the first blow, but did not expect the United States to be hit as severely as she was in the attack on Pearl Harbor.
An attack by Japan on the U.S. could not guarantee the U.S. would declare war on Germany. After such an attack, American public anger would be directed at Japan, not Germany, just as happened. The Tripartite Pact (Germany, Italy, Japan) called for each to aid another in defense; Japan could not reasonably claim America had attacked Japan if she struck first. For instance, Germany had been at war with the UK since 1939, and with the USSR since June 1941, without Japanese assistance. There had been a serious, if low-level, naval war going on in the Atlantic between Germany and the U.S. since summer of 1941, as well. Nevertheless, it was only Hitler's declaration of war on 11 December, unforced by treaty, that brought the U.S. into the European war.
Clausen and Lee's Pearl Harbor: Final Judgement contains some interesting information on the intelligence available to Roosevelt and Churchill prior to the attack. On page 367 in the Appendix is a Purple message, dated 29 November 1941, from the Japanese Ambassador in Berlin to Tokyo. A closing paragraph reads:
... He (Ribbentrop) also said that if Japan were to go to war with America, Germany would, of course, join in immediately, and Hitler's intention was that there should be absolutely no question of Germany making a separate peace with England. ...
According to David Irving, Churchill (having full access to Purple traffic) was well aware of this message, noting it in red ink. While theorists challenging the conventional view the attack was a surprise treat this as a guarantee to join after Japan's attack, it can as easily be taken as a guarantee to come to Japan's aid, as Germany had done for Italy in Libya.
Release of information – delays and problems with declassification
Conflicting stories regarding FOIA (Freedom of Information Act) requests for the source materials used or materials available at the National Archives are also common among the debate. However, much information has been said to have been automatically destroyed under a destruction of classified information policy during the war itself. Note various authors have nevertheless continued to bring classified Pearl Harbor materials to light via FOIA.
Another issue in the debate is the fact neither Admiral Kimmel nor General Short ever faced court martial. It is alleged this was to avoid disclosing information showing the U.S. had advanced knowledge of the attack. When asked, "Will historians know more later?", Kimmel replied, "' ... I'll tell you what I believe. I think that most of the incriminating records have been destroyed. ... I doubt if the truth will ever emerge.' ..." From Vice Admiral Libby, "I will go to my grave convinced that FDR ordered Pearl Harbor to let happen. He must have known." It is equally likely this was done to avoid disclosing the fact Japanese codes were being read, given there was a war on.
Unreleased classified information
Part of the controversy of the debate centers on the state of documents pertaining to the attack. There are some related to Pearl Harbor which have not been made public. Some may no longer exist, as many documents were destroyed early during the war due to fears of an impending Japanese invasion of Hawaii. Still others are partial and mutilated. A purported transcript of a conversation between Roosevelt and Churchill in late November 1941 was analyzed and determined to be fake. There are claims about these conversations; much of this is based on fictional documents, often cited as "Roll T-175" at the National Archives. There is no Roll T-175; NARA does not use that terminology.
The Mystery of the Attack on Pearl Harbor
The Gathering Storm: On 7 December 1941, the Japanese surprise attack on the American naval base at Pearl Harbor destroyed a large portion of the U.S. Pacific fleet and thrust the United States into the Second World War. Following a moving speech by President Franklin D Roosevelt, Congress declared war on Japan the following day. Roosevelt stated that the "United States of America was suddenly and deliberately attacked by naval and air forces of the empire of Japan." However, was the "date which will live in infamy" really a surprise attack, or were some high level American and British officials, possibly even Roosevelt and Churchill, aware of Japanese intentions well in advance?The attack came on the heels of the Japanese government's decision, under Premier Hideki Tojo, that the United States would take an active role in the Pacific theater in the event that Japan attacked Southeast Asia.
With the dramatic decrease in the amount of American oil and other raw materials being shipped to the Japanese, they realized that the only way to maintain the integrity of the Japanese military machine would be to assimilate the natural resources of Southeast Asia into the empire. Therefore, war with America was inevitable and unavoidable. With this in mind, the Japanese began negotiations with the United States while simultaneously preparing invasion plans of the American Philippines, the Dutch East Indies, and British Malaya. One major component of these invasion plans was to neutralize the greatest threat to Japanese operations, the American Pacific fleet. With the presence of such a formidable opponent, which had established its home base at Pearl Harbor in May 1940, the Japanese realized that it would be difficult to subjugate Southeast Asia. If the majority of the fleet was eliminated in one massive assault, not only would they be able to conquer these territories, but they would also be able to fortify them as well. The attack on Pearl Harbor was devised by Admiral Isoroku Yamamoto, commander-in- chief of the Combined Japanese Fleet.
The surprise air attack against the American fleet was a very high gamble. First, the Japanese fleet of six aircraft carriers, two battleships, and a number of cruisers, destroyers, and support vessels had to proceed undetected to within striking distance of the port. Then, once the attack was completed, the fleet, with its depleted arsenal, had to return under the threat of a counter attack.
At Dawn We Slept
Under the direction of Vice Admiral Chuichi Nagumo, the attack fleet assembled near the Kurile Islands on 22 November after leaving Kure Naval base on 10 November. In order to avoid detection, the fleet followed a storm front and kept strict radio silence while Tokyo broadcast false commands to decoys in other locations. The Japanese fleet arrived to within 275 miles of Oahu and sent its first attack wave into the air at 6:00 AM. This force, composed of 49 bombers, 40 torpedo planes, 51 dive bombers, and 43 fighters, arrived at Pearl at 7:55 AM (1:50 PM Washington time) and continued the assault until 9:45 AM. Shortly after the completion of the first attack, the second wave of 54 bombers, 78 dive bombers, and 36 fighters arrived. In the end, nineteen ships were either disabled or sunk, including all eight American battleships.
In addition, 164 U.S. planes were destroyed and 128 damaged while 2,335 American sailors, soldiers, and marines were killed along with 68 civilians and 1,178 were wounded. Although Yamamoto's plan called for a third attack wave to destroy the 4.5 million gallons of fuel oil and support facilities, Nagumo felt that the threat of a counter attack was too great, so he ordered the fleet to turn towards home.
When the news arrived about the attack on the continental United States, the Americans were stunned. Immediately, any talks of isolationism or pacifism were swept away. Yet, even though Yamamoto's attack was a tactical success, it turned out to be a strategic failure. With the repair facilities and fuel depots still intact, the Americans quickly returned six of the eight battleships to active service. Also, the submarine facilities were still intact, allowing the American submarine fleet to immediately threaten Japanese shipping.
Perhaps the most important reason why the attack on Pearl Harbor was a strategic failure was the fact that the Pacific Fleet's three aircraft carriers were not at Pearl. The Enterprise was delivering aircraft to Wake Island, the Lexington was on a similar mission to Midway Island, and the Saratoga was being overhauled in California. Had these carriers been at Pearl Harbor on that fateful day, the war would have taken a dramatically different course. As the war progressed, the Lexington was lost at the Coral Sea after inflicting heavy losses on the Japanese military; the Saratoga earned seven battle stars; and the planes from the Enterprise played an important role in the destruction of four Japanese carriers at the battle of Midway. Obviously, the loss of just one of these important vessels would have made the American cause very difficult if not dire.
A date which will live in infamy but may always be shrouded in mystery
Today, as more evidence comes to light, some scholars have claimed that Roosevelt knew of the attack beforehand and that he allowed it to occur in order to silence the isolationist-interventionist debate and enter the war in full stride. However, no smoking gun has ever turned up to support this theory even though some of the details are quite compelling. Since 1940, the U.S. had been supporting the British in their attempts to hold back the Nazi threat while Japanese-American relations were worsening by the day. American involvement in the Second World War was not only becoming probable, but a necessity to the free nations of the world.
There is even speculation that British intelligence had broken the Japanese Navy's main administrative code, JN25, in 1941 and Prime Minister Winston Churchill refused to reveal the impending attack to the Americans so as to draw the U.S. into the conflict. Also, British double agent Dusko Popov, in what became known as the Tricycle Affair, reported that Berlin had asked him to procure information about Pearl Harbor in mid 1941 -- information which would have been relayed by the Japanese consulate in Berlin to Tokyo through the "Purple" machine. Finally, Kimmel and Short were not informed that spies were transmitting information from the Japanese consulate at Honolulu about the disposition of the Pacific fleet at Pearl Harbor; an event which surely would have place the entire installation on alert. All in all, there is enough evidence to keep historians questioning what actually occurred in the events leading up to 7 December 1941 -- a date which will live in infamy but may always be shrouded in mystery.
The McCollum memo, also known as the Eight Action Memo was a memorandum, dated October 7, 1940 (a year before the Pearl Harbor attack, sent by Lieutenant Commander Arthur H. McCollum, who "provided the president with intelligence reports on [Japan]... [and oversaw] every intercepted and decoded Japanese military and diplomatic report destined for the White House" in his capacity as director of the Office of Naval Intelligence's Far East Asia section. It was sent to Navy Captains Dudley Knox, who agreed with the actions described within the memo, and Walter Stratton Anderson.
The memo outlined the general situation of several nations in World War II and recommended an eight-part course of action for the United States to take in regards to the Japanese Empire in the South Pacific suggesting the United States provoke Japan into committing an "overt act of war". The memo illustrates several people in the Office of Naval Intelligence promoted the idea of goading Japan into war:
It is not believed that in the present state of political opinion the United States government is capable of declaring war against Japan without more ado [...] If by [the elucidated eight-point plan] Japan could be led to commit an overt act of war, so much the better.
The McCollum memo was first widely disseminated with the publication of Robert Stinnett's book Day of Deceit: The Truth About FDR and Pearl Harbor. Stinnett presents the memo as part of his argument the Roosevelt Administration conspired to secretly provoke the Japanese to attack the United States in order to bring the United States into the European war without generating public contempt over broken political promises. Roosevelt had recently issued a campaign promise the United States would not become entangled in Europe's war under his watch. Stinnett omits to mention McCollum never had contact with Roosevelt, and Stinnett's claims to the contrary are false. Moreover, Stinnett attributes to McCollum a position McCollum expressly refuted. McCollum's own sworn testimony also refutes it.
The Eight-Action plan
The McCollum memo contained an eight-part plan to counter rising Japanese power over East Asia:
1. Make an arrangement with Britain for the use of British bases in the Pacific, particularly Singapore
2. Make an arrangement with Holland for the use of base facilities and acquisition of supplies in the Dutch East Indies
3. Give all possible aid to the Chinese government of Chiang-Kai-Shek
4. Send a division of long range heavy cruisers to the Orient, Philippines, or Singapore
5. Send two divisions of submarines to the Orient
6. Keep the main strength of the U.S. fleet now in the Pacific in the vicinity of the Hawaiian Islands
7. Insist that the Dutch refuse to grant Japanese demands for undue economic concessions, particularly oil 8. Completely embargo all U.S. trade with Japan, in collaboration with a similar embargo imposed by the British Empire
Reception of the Eight Actions
The memo was read and appended by Captain Knox, who, despite being seemingly reluctant to "precipitate anything in the Orient", ultimately concurs. Specifically, he wrote:
It is unquestionably to our interest that Britain be not licked - just now she has a stalemate and probably can't do better. We ought to make certain that she at least gets a stalemate. For this she will probably need from us substantial further destroyers and air-reinforcements to England. We should not precipitate anything in the Orient that would hamper our ability to do this - so long as probability continues. If England remains stable, Japan will be cautious in the Orient. Hence our assistance to England in the Atlantic is also protection to her and us in the Orient. However, I concur in your courses of action. We must be ready on both sides and probably strong enough to care for both.
Stinnett writes that while "no specific record has been found by the author indicating whether [Anderson] or Roosevelt actually ever saw it", "a series of secret presidential routing logs plus collateral intelligence information in the Navy files offer conclusive evidence that they did see it". His evidence of "secret presidential routing logs" is not provided. Stinnett goes on to write, "throughout 1941, it seems, provoking Japan into an overt act of war was the principal policy that guided FDR's actions against Japan" and "Roosevelt's cabinet members, most notably Secretary of War Henry L. Stimson, are on record favoring the policy, according to Stimson's diary". Further evidence that suggests Roosevelt had seen the memos was his support of "pop-up" cruises, an elaboration upon Actions 4 and 5 of the eight recommended actions detailed in the memo: "I just want them to keep popping up here and there and keep the Japs guessing. I don't mind losing one or two cruisers, but do not take a chance on losing five or six."
Admiral Husband E. Kimmel, on the other hand, opposed the "pop-up" cruises, saying they were "most ill-advised and will result in war if we make this move", but "the decision [on the 'pop-up' cruise matter] may go against me". In fact, at the time, Kimmel did not know of Washington's eight-action policy.
Admiral James O. Richardson also opposed the plan and "quoted the President as saying: 'Sooner or later the Japanese would commit an overt act against the United States and the nation would be willing to enter the war'."
Also, Admiral Nimitz turned down the command of the Pacific Fleet so that he would not become the scapegoat if the Japanese attacked the United States by surprise. In a History Channel interview, Admiral Chester Nimitz Jr. described his father's political maneuver:
He said, 'It is my guess that the Japanese are going to attack us in a surprise attack. There will be a revulsion in the country against all those in command at sea, and they will be replaced by people in positions of prominence ashore, and I want to be ashore, and not at sea, when that happens.' 12]
The characterization of the McCollum memorandum as a recipe for war was not accepted by U. S. Army military historian Conrad Crane, who wrote:
A close reading shows that its recommendations were supposed to deter and contain Japan, while better preparing the United States for a future conflict in the Pacific. There is an offhand remark that an overt Japanese act of war would make it easier to garner public support for actions against Japan, but the document's intent was not to ensure that event happened.
* Though a major exposer of the Pearl Harbor conspiracy, Robert Stinnett is sympathetic regarding FDR's motives. He writes in his book:
As a veteran of the Pacific War, I felt a sense of outrage as I uncovered secrets that had been hidden from Americans for more than fifty years. But I understood the agonizing dilemma faced by President Roosevelt. He was forced to find circuitous means to persuade an isolationist America to join in a fight for freedom.