Hawaii Operation

I. Postwar Domestic and Foreign Criticism

Numerous criticisms have been voiced since the end of the war, both at home and abroad, regarding the Hawaii Operation.* As far as the writer’s knowledge goes, however, domestic criticism appears to be restricted to that of a political nature aimed solely at laying the blame on the Hawaii Operation for having ignited a rash war. In other words, there seem to be no instances yet of any attempt to analyze and criticize the operation from a purely strategical or tactical standpoint.

Naturally enough, this subject has been given the most serious attention by the United States. In his work, The Rising Sun in the Pacific, volume III of The History of U. S. Naval Operations in World War II, Dr. Samuel Eliot Morison bitterly criticizes the Hawaii Operation in the following manner: “It would be impossible for anyone to find in the annals of history an operational precedent having brought about a more fatal blow upon the aggressor himself than this attack. Tactically speaking, the Japanese committed the blunder in the Pearl Harbor attack of concentrating their attacks only on warships instead of directing them on land installations and fuel tanks. Not only was it strategically a folly, but politically too, it was an unredeemable blunder.”

Dr. Morison goes on to remark: “Although they [the Japanese] succeeded in destroying the [U. S.] battleship fleet and wiping out the land air force, they overlooked various naval installations in Pearl Harbor. Among them were repair shops which later were able to repair those ships damaged in the attack within an astoundingly short space of time. They furthermore did not make attacks upon power facilities and fuel tank dumps which were stored up to their huge capacity. As duly expressed in the opinion of Admiral Thomas S. Hart, Commander-in-Chief, Asiatic Fleet, at the time, the loss of those installations would probably have delayed the U. S. counter-offensive in the Pacific more than did the actual damage to the U. S. vessels.”

Dr. Morison explains his contention that, strategically, it was a ridiculous and stupid operation, as follows: “If the Japanese forces had not carried out their attack on Pearl Harbor, the Rainbow 5 operational plan, which was to be started with the declaration of war, would have been carried out, and the U. S. Pacific Fleet would have attacked Japanese posts in the Marshall and Caroline archipelagoes, including Truk Island.”

This meant that, had the Hawaii Operation not been conducted by the Japanese, the U. S. Fleet would instead have launched an offensive, and the Japanese Navy, accordingly, could have launched its long-cherished countering operations by calmly remaining in waiting. The Japanese Navy had, for thirty years, been arduously engaged in studying and training in the so-called “counter-attack decisive battle against the U. S. Fleet,” in which an American onslaught was to be countered and destroyed in the seas adjacent to Japan, as the only sure way of gaining a victory. No offensive operation against Hawaii had ever been contemplated in the past.

Dr. Morison’s contention, therefore, may mean that, by carrying out the Hawaii Operation, the Japanese Navy committed the folly of forever losing an opportunity to realize its fundamental operational plan. In contending that it was an unredeemable political blunder, moreover, Dr. Morison points out that the Pearl Harbor attack served to arouse the united determination of the American people, fighting under the slogan “Remember Pearl Harbor!" to crush the Japanese Empire.

At complete variance to this view of Dr. Morison, however, is that held by Admiral William V. Pratt, one of the most illustrious figures of the modern U. S. Navy. In cornmeriting upon the Hawaii Operation in a letter addressed to former Admiral Kichisaburo Nomura, who is his intimate Japanese friend, the American admiral described the Japanese attack upon Pearl Harbor as a most thoroughly planned and daring project —a strategical success of rare precedence in history. The question as to which of the two, the historian or the strategist, holds the more correct view will be left to the good judgment of the reader.

Since the Pacific war ended so tragically for the Japanese people there seem to be some among them who do not wish even to be reminded of the Hawaii Operation, feeling that the entire prosecution of the war was an act of folly. On the other hand, there are a considerable number who feel that those actually concerned in the operation should compile a true and unbiased historical account of it. This essay is a contribution towards that end.

II. The Roles of Admirals Shimada and Yamamoto

Admiral Shigetaro Shimada, the Navy Minister at the time Japan went to war, wanted by all means to prevent the United States from becoming an enemy and taxed himself to find some means of enabling Japan to declare war only after the United States had opened hostilities. His idea was for Japan to declare war on Britain and the Netherlands, but to resort to arms against the United States only after she was challenged by the latter.

Admiral Shimada had long been with the Naval General Staff when he was appointed Navy Minister, and he had a profound knowledge of naval operations. He advocated passive operations against the United States, but at the same time requested the Naval General Staff, which was the responsible office for operations, to make a study of the problem. He preferred, if worse came to worse, to let the United States strike first, thus enabling Japan to declare war with honor. Had things turned out as Shimada wished, not only would there have been no cry of “Remember Pearl Harbor!” but the political developments pointed out by Dr. Morison would have taken a different course.

Shimada believed there would be little chance to exploit a conquest of Southeast Asia if our long Southern Operation line, stretching far below the equator, was flanked by a dominant U. S. fleet, prepared to strike at the best time and in a manner of its own choosing. A political guarantee of non-intervention by the United States was a desired prerequisite for launching the Southern Operation, but that was out of the question in the situation prevailing both at home and abroad. Since there was no sure political guarantee, it was obvious that the United States would sooner or later join on the side of Britain and the Netherlands in a war against Japan, even if she could be prevented from entry in its early stage.

In reply to the Japanese Government’s inquiry with respect to her attitude toward Germany, the U. S. Government stated in its note dated July 16, 1941, “the use of our right of self-defense against Germany is our own proper responsibility”; and moreover, “any state attempting, at this juncture, to compel the United States to remain neutral shall be regarded as belonging to the same camp of aggressors.” From its extremely scathing tone, it could readily be surmised that the note not only indicated the stern stand of the United States toward Germany, but also clarified her attitude toward Japan.

Even though the United States could be kept out of the war at its outset, it was absolutely certain that she would not remain as an idle spectator forever. Therefore, the final judgment reached in 1941 was that there was no other way of Japan’s gaining victory except by forestalling America’s armed intervention, since a war with the United States had already been deemed inevitable.

Since the Japanese realized that there was no means of isolating the United States from operations in Southeast Asia, the main target of the Japanese Navy from the outset was to be the U. S. fleet, and all other objectives were to be treated as secondary. How to accomplish the destruction of the U. S. fleet was the grave responsibility entrusted to Admiral Yamamoto, the Commander-in-Chief, Combined Fleet.

During basic maneuvers of the Combined Fleet, held sometime between April and May, 1940, I was Admiral Yamamoto’s Chief of Staff. One feature of the exercises was a mock air attack. The fleet skillfully eluded the first and second assault waves of the imaginary torpedo bombers, but sustained theoretical heavy damage, reducing its strength to one-half, when the “enemy” successfully launched aerial torpedoes from both flanks in spite of the skillful elusive action of the fleet.

“There is no means for a surface fleet to elude aerial torpedoes simultaneously launched from both sides,” I said to Admiral Yamamoto, “It seems to me that the time is now ripe for a decisive fleet engagement with aerial torpedo attacks as the main striking power.”

“Well,” replied Yamamoto, “it appears that a crushing blow could be struck on an enemy surface force by mass aerial torpedo attacks executed jointly with shore-based air forces.” The admiral was undoubtedly thinking at that moment of the powerful U. S. fleet concentrated in Pearl Harbor.

Ever since 1909 the Japanese Navy had made the U. S. Navy its sole imaginary enemy. It was but natural that, in the fleet training of 1940, due consideration was given to the strategic situation under which the U. S. fleet was concentrated in Hawaii and steadily making preparations for war, thus showing its determination to resort to armed intervention in opposition to Japan’s policy toward China. The Japanese Fleet had for thirty years studied and trained for a decisive fleet counter-offensive as its basic evolution, but such an operation, whose nature was in the final analysis passive, involved the great disadvantage of leaving the initiative in the enemy’s hands. Moreover, the situation was such that, as time passed, the balance of naval strength between the two would gradually favor the United States, with the chance of Japan’s gaining a victory steadily diminishing. The Japanese Navy was accordingly compelled to find some means for assuring an early decisive engagement. Now, with the U. S. fleet already advanced to its Hawaiian base, it could readily advance to the Western Pacific, thus creating a definite threat to Japan. As long as it remained at its Hawaiian base, it created a strategical situation incomparably more tense and threatening to the Japanese than had existed when it was based on the Pacific coast. Every Japanese naval officer realized that a crushing blow could be inflicted if a successful attack could be launched on distant Hawaii, thereby depriving the enemy of the initiative and assuring us an impregnable position. However, it was not believed that the Japanese Navy could undertake an Hawaiian attack because of the operational limitations of its warships. But Fleet Admiral Yamamoto, the “father of naval aviation,” had long believed that future wars would be decided by air power, and he had improved and developed the Japanese Navy’s air arm to that end. As a consequence, he alone originated the idea of an aerial surprise attack—and thus made the impossible possible.

III. My Connection with Hawaii Operation

Upon promotion to Rear Admiral on November 1, 1939, I was transferred from command of the fleet-flagship, the Nagato, to duty as the Chief of Staff, Combined Fleet, under Admiral Yamamoto, until I was transferred in April, 1941, to duty as the Chief, First Bureau, Naval General Staff. Since the position of the Chief of the First Bureau placed me in charge of operations, my duties in both capacities associated me with the Hawaii Operation from beginning to end. It may be said that except for the late Admiral Yamamoto, I was the only person acquainted with detailed plans of the operation from the moment of its conception.

“I want a flier, whose past career has not influenced him in conventional operations, to study this problem,” Commander-in-Chief Yamamoto said, and then asked me what I thought about it. This occurred toward the close of 1940, after the annual fleet training exercises had been completed.

“It is a fine idea, sir,” I replied.

“For the time being, I will keep the matter secret from other Fleet staff officers, except for the aviator assigned to the problem, and would like to ask you to keep it for your personal study,” he said. Thereupon the Admiral secretly summoned his selected naval aviator, Rear Admiral Takijiro Ohnishi, and entrusted him with planning the Hawaii Operation.

Ohnishi had long been an airman to the core and ranked foremost in the practical field, in contrast to Admiral Yamamoto, whose main experience had been in the field of naval air organization and administration. They were congenial friends of long standing. Since Ohnishi had not been long with the Naval General Staff, there was little fear that he might be hampered by conventional operational doctrine. Moreover, he was noted for his cautious and logical thinking as well as for his vast experience. Admiral Yamamoto could not have made a better choice in his selection of an officer to whom to entrust this important study.

Toward the end of April, 1941, Admiral Ohnishi completed the general plan. He called on me at my office in the Naval General Staff and explained his plan as follows:

“This operation involves two difficult problems. One of them is the technical difficulty of launching aerial torpedo attacks in Pearl Harbor, which is so shallow that aerial torpedoes launched by ordinary methods would strike the bottom. The other concerns the tactical problem—whether a surprise can be made successfully. This operation apparently cannot be carried out without a surprise element.”

Even though he pointed out numerous difficulties involved in the operation, Ohnishi estimated, in the early stage of planning, that it had a sixty per cent chance of success. I thought its chance to be forty per cent, since I took operational difficulties more seriously than did Ohnishi. Opposition to the operation which was later raised by the Naval General Staff arose mainly from my opinion. Had I from the very beginning been entrusted with the study of the idea instead of Ohnishi, I would certainly have recommended to Commander-in-Chief Yamamoto that the Hawaii Operation be abandoned.

In the early part of September, 1941, I remember that Ohnishi called on me again in the Naval General Staff and said that the Hawaii Operation now seemed too risky and he wanted to recommend to Admiral Yamamoto that it be given up. Later Ohnishi accompanied by Rear Admiral Ryunosuke Kusaka, then Chief of Staff to Vice Admiral Chuichi Nagumo who later commanded the Hawaii Operation Force, called on Admiral Yamamoto on board the flagship Nagato, and earnestly advised the Admiral to give up the operation. But Admiral Yamamoto firmly stuck to his guns.

IV. The General Staff’s Opposition

With Japan’s resolution to go to war with the United States when necessary—a decision made at the Imperial Conference held on September 6, 1941—war preparations were put in full swing.

Previously, Admiral Yamamoto had received Ohnishi’s plan for the Pearl Harbor attack and he had made it one of his Fleet’s operational studies, and his staff continued to work on it. As a result, the Admiral succeeded in drafting an operation plan upon which he could place full confidence of success. From about the middle of September earnest discussions were exchanged between the Naval General Staff and the Combined Fleet headquarters with regard to the general operational plan which was to be carried out in the event of war. With it, the problem of the Hawaii Operation inevitably came to the fore.

In early October, staff officers of the Combined Fleet went up to Tokyo under orders of Admiral Yamamoto and reported to the General Staff that they desired to launch an attack on Hawaii at the outset of war, if and when it should be started. But the General Staff did not approve the proposal, on the ground that the Hawaii Operation was inadvisable from the standpoint of the over-all operational concept. The Naval General Staff doubted that the Hawaii Operation would succeed. Much would be lost if the operation failed. Moreover, the operation gave rise to the fear that it might cause an unfavorable effect on the negotiations then being conducted between the United States and Japan, because preparatory initiation of the operation was necessary prior to the termination of the negotiations.

The objectives of the Naval General Staff were essentially five in number:

1. Success of Hawaii Operation was dependent upon the achievement of surprise.

The powerful American fleet concentrated in Hawaii was too strong for conventional attack by our task force. Without surprise, our fleet could never achieve success. The prerequisite for a successful surprise attack was the secrecy of the movements of its task force. Since the operation was on a large-scale, employing as many as sixty ships which had to be dispatched one month before the outbreak of war in the Eastern Pacific, it was likely to attract attention, especially since the southerly advance was generally believed to be Japan’s chief strategy in the event of war. In view of the tense international situation, it was believed that the close intelligence network of the United States and Great Britain had been widely extended, and that of their ally, Soviet Russia, was also thought to be dangerous. Therefore, much apprehension was entertained on whether the secrecy of the operation could be kept.

Besides, there was the fear that the task force might meet hostile or neutral ships en route to the point of attack. In that event all would be lost if our task force were to meet any ship at sea which might be expected to send a radio despatch stating, “Japanese fleet proceeding eastward in great strength.”

2. The Hawaii Operation was not so indispensable as to be executed regardless of risk.

Unless a blow was dealt at the outset of war by carrying out the daring Hawaii attack, the American fleet would certainly come out to attack us. It seemed unlikely that the enemy would come straight to our homeland seeking a decisive battle; rather, it would first establish advance bases in the Marshall Islands and then attempt the island-hopping strategy by gradually advancing its bases.

In that case, we would be given ample time to concentrate all our available strength in a decisive contact engagement for which our Navy had long studied and trained. It would be wiser to seek a decisive battle in familiar waters than to attempt the Hawaii Operation with its risk of failure.

3. Almost all naval vessels participating in the Hawaii Operation would have to be refueled at sea en route; destroyers at least twice.

Since the establishment of the “Empire’s National Defense Policy” in 1909, the Japanese Navy had accepted defensive operations against the United States as their fundamental policy, so that the radius of action of our ships and planes was generally short. Meteorological statistics showed that on only seven days during the month were conditions favorable for refueling destroyers at sea on the North Pacific route which the fleet would have to take to avoid commercial traffic lanes. If refueling could not be carried out, not only would the Hawaii Operation fail, but all the units involved would have been uselessly diverted from other planned operations.

Lastly, one hitch was apt to lead to another. If refueling at sea met with difficulties, it would necessitate the transmittal of radio despatches. Radio transmission would immediately break the secrecy of the operational force’s movement, thus tragically spoiling the elaborately planned operation at the last moment. A good example of this was seen later in the Battle of Midway. Should the secrecy of the Hawaii Operation be broken en route to the attack, not only would the Hawaii attack force itself be endangered, but the indispensable southern operation, as a whole, would be adversely affected.

4. High probability that the task force would be spotted by enemy patrol planes at the point from which the attacking planes were to be launched, with consequent enemy interdiction.

Alertness around the Hawaiian Islands had gradually been intensified. The Radio Intelligence Section of the Japanese Naval General Staff knew that the daily air patrol had been extended to 600 miles from Oahu. Since our carrier force had to close to within 200 miles of the target, there was a considerable risk that it might be counterattacked by the enemy before launching its attacks.

5. Knowledge that it would break down the negotiations between the United States and Japan.

The Navy did not give up hope of success in the negotiations until the last moment. Admiral Nagano, Chief of the Naval General Staff, had placed much hope in Admiral Kichisaburo Nomura, the Ambassador in Washington, who was one of his close friends. Nagano, who had believed that “nothing can be done here in Japan with the negotiations between the United States and Japan, and that only Admiral Nomura could break the deadlock,” rejoiced greatly at the news received from Ambassador Nomura about October 20 to the effect that there was some hope of solving the stalemate. The Chief of Staff repeatedly told me, “Nomura is a great fellow, and no one but he could succeed.” The firm confidence Nagano placed upon Nomura may well be seen from the fact that, even when Admiral Yamamoto came up to Tokyo on December 1 on his last visit, the policy of withdrawing all forces in the event of a favorable turn to the negotiations was confirmed between Nagano and Yamamoto.

V Verdict Given by Admiral Nagano

In the meantime, Admiral Yamamoto, as Commander-in-Chief, Combined Fleet, had trained his fleet in the Inland Sea and had drawn up emergency operational plans. After receiving his staff’s report that they had failed to secure the approval of the Naval General Staff on the Hawaii Operation upon which he placed the utmost importance, the Admiral elaborated on his plan. Rear Admiral Ugaki, Chief of Staff, and other staff officers went up to Tokyo again to submit his recommendation to the General Staff. Salient points stressed on that occasion as Yamamoto’s opinion were as follows:

“The present situation, i.e., that of the U. S. fleet in the Hawaiian Islands, strategically speaking, is tantamount to a dagger being pointed at our throat. Should war be declared under these circumstances, the length and breadth of our Southern Operations would immediately be exposed to a serious threat on its flank. In short, the Hawaii Operation is absolutely indispensable for successful accomplishment of the Southern Operations.

“Moreover, when we consider the naval strength ratio between the United States and and Japan, we would have no chance of victory unless a decisive attack was launched at the earliest possible opportunity. Therefore, the Hawaii Operation is truly indispensable to the accomplishment of the mission assigned the Japanese Navy. Unless it is carried out the Commander-in-Chief, Combined Fleet, has no confidence that he can fulfill his assigned responsibility.

“This operation is beset with numerous difficulties, none of which, however, makes it impossible. What concerns us most is the weather condition; but, if there are seven days in a month when refueling at sea is possible, the chance of success is by no means small. If good fortune is bestowed upon us, we will be assured of success. Should the Hawaii Operation by chance end in failure, that would merely imply that fortune is not on our side. That should also be the time for definitely halting all operations.”

An extremely grim resolution could be clearly read between those lines.

After carefully listening to the Vice Chief of Staff’s detailed explanation of Yamamoto’s real intention and his practical plan, Nagano, as Chief of Staff, finally gave the following verdict on the issue:

“If he has that much confidence, it’s better to let Yamamoto go ahead.”

As far as the Navy was concerned, with these words the Hawaii Operation was formally approved as a plan. Needless to say, the Naval General Staff thereafter did its best to make this operation successful. At the same time, it also drew up a plan whereby the Hawaii Operation force would turn back immediately in the event that a setback or hitch occurred en route.

VI. The Time for Going to War

In the Imperial Conference held on September 6, 1941, it was decided that, “in view of the potentiality of the Empire’s national strength, Japan is determined without delay to go to war with the United States (Great Britain and Netherlands) in the event that there is little prospect of achieving our aims by as late as early October.” This decision meant that, considering the possible severance of the flow of essential import materials because of the embargo against this country by the so-called ABCD ring (American- British-Chinese-Dutch), no time should be wasted if and when war was finally deemed unavoidable. Among those essential materials, particular importance was placed on oil.

“One of the major causes for this war, I think,” said Admiral Nagano in the U. S. Strategic Bombing Survey’s interrogation which was conducted after the war, “was the oil problem. Not only the Army and Navy, but the government also, showed a great concern in this problem, because this country faced a serious oil shortage, since the United States, Britain, and Netherlands refused to sell oil to our country.”

“We believed that we would be able to get oil from the southern region,” stated Ambassador Nomura during the same interrogation. “Our oil resources were so limited that we had to secure oil from those islands at all costs.”

The Japanese Navy’s operational plan called for a stockpile of oil for two years’ consumption as the minimum prerequiste for going to war. Thanks to its oil policy, which had been followed for a long time, the Japanese Navy had stored up enough oil to meet that demand, but the Army barely had done so. Therefore, a further continuation of the oil import embargo was considered intolerable from the point of view of maintaining the fighting strength of Japan. War should be avoided, if possible; but, if and when war was finally deemed unavoidable, the sooner it was started, the better.

Of course, the oil problem was not the only factor determining the time for going to war. There were many others, political and military. Another consideration was the possibility that the operation might well be hampered by foul weather because it was the northeast monsoon season. Still another consideration was preservation of secrecy of the operation prior to the outbreak of the war. From the operational standpoint, it was apparent that “one day’s delay would mean one day’s disadvantage.” Reflecting the tense international situation, war preparations in the ABCD ring were rapidly being pushed. The U. S. fleet standing by at Hawaii was improving its war preparations, and the U. S. Army Air Force in the Philippines and the British air strength in Singapore were rapidly being augmented.

When the so-called “Ogikubo” conference was held on October 12, 1941, in which the final attitude of the third Konoye Cabinet toward “peace or war” was decided, Admiral Oikawa, the Navy Minister, made the following statement of the Navy’s view.

“Now we have reached a cross-road where a choice for ‘peace or war’ should be made. Speaking for the Navy, we will find ourselves at a complete loss, if asked to go to war, until such time as the current negotiations between the U. S. and Japan reach a deadlock.”

Based on the belief that an early commencement of operations would be advantageous for the aforementioned reasons, the Imperial General Headquarters originally intended to go to war on December 1. But when top-ranking Army and Navy officers, including General Terauchi and Admiral Yamamoto, assembled in Tokyo at the beginning of November, 1941, for a briefing on the Southern operations, the date was postponed to December 8 (Tokyo time) by request of Yamamoto, who considered a successful execution of the Hawaii Operation a prerequisite. Yamamoto indicated complete accord with the idea of attacking the U. S. fleet on Sunday, when the ships were more likely be in Pearl Harbor for the weekend, but he preferred the second Sunday of December over the first because his fleet would not have sufficient time to prepare for the original date. The Imperial General Headquarters approved his request.

Thus, it was decided to raise the curtain of the Pacific War, with the first attack on Hawaii to be launched at 0830 of December 8 (December 7, Hawaii time).

VII. The Hawaii Operation and its Promulgation

Since Nagano’s approval, as Chief of the General Staff, to Yamamoto’s Hawaii attack plan meant no more than an informal decision within the naval command, various procedures had to be worked out before a formal decision could be made. Under the old Japanese Constitution, the opening of hostilities was the prerogative of the Emperor’s supreme command. The Chief of the Naval General Staff was responsible to the Throne for naval operations. After the China Incident broke out in 1937, the Imperial General Headquarters had been established with membership made up of the Chiefs of the Army and Navy General Staffs and the ministers of both the War and Navy Departments. It was, therefore, necessary for the Chief of the Naval General Staff to propose the plan of the Hawaii Operation to the Chief of the Army General Staff and also to both Ministers of the War and Navy Departments.

The operation plan had also to be discussed at the Liaison Conference between the Government and the High Command. The Liaison Conference had been established about a year before, when the need of a supreme body for maintaining a close and smooth relation between military strategy and politics was keenly felt as a result of the China Incident. The first meeting of the conference was held on July 27, 1940. This body, which later became the Supreme War Directing Conference, was composed of the Premier, Foreign Minister, War Minister, Navy Minister, and Chiefs of the Army and Navy General Staff as regular members. As necessity arose, the Finance Minister and the Minister of the Interior also attended the conference. But, since the Hawaii Operation was an important operation which required top secret security, it was disclosed only to the Premier and the Foreign Minister in addition to the Army and Navy members of the conference.

After the above procedures were followed, the Chief of the Navy General Staff asked for Imperial sanction, thus formally acknowledging it as the Japanese Navy’s operational plan. This occurred on November 5, 1941.

On the same day, Imperial Naval General Staff Order No. 1 was issued ordering the Combined Fleet to make operational preparations as follows:

Imperial Naval General Staff Order No. 1

Nov. 5, 1941

To: Commander-in-Chief Combined Fleet Isoroku Yamamoto

Via: Chief of Naval General Staff Osami Nagano By Imperial Order

1. The Empire has decided to schedule various operational preparations for completion in the early part of December in view of great fears that she will be obliged to go to war with the United States, Britain, and the Netherlands for her self-existence and self-defense.
2. The Commander-in-Chief Combined Fleet will make necessary operational preparations.
3. Detailed instructions will be given by the Chief of the Naval General Staff.

VIII. Japan’s Declaration of War Accidentally Delayed

How to integrate diplomatic policies and military operations is a problem of the utmost importance. The case of the last Pacific war was no exception. Since the war was to be started by the attack upon Hawaii, the manner in which Japan arranged the time of commencing that attack and the sending of the ultimatum to the United States still leaves much room for discussion as an important subject related both to the government administration and to the high command.

The Hawaii Operation obviously could not be conducted without surprise. This is the very reason why it was decided that the war was to be started with that operation. Under no circumstance, should diplomatic steps be taken which would give the United States time to prepare counter measures to our surprise attack.

Since International Law experts maintained that it is legal to declare war if the declaration precedes the commencement of hostilities—even though only one or one-half second in advance (the interval of time is of no concern), it was believed that the operation could be carried out in accordance with diplomatic usage if the declaration could be sent to the United States at such time as to prevent her from making preparations. In this way, it was expected that no hitch in the execution of the operations would occur. Thus the government and the high command mutually decided to send the declaration in accordance with the procedure of international law.

The issue of Japan’s sending the declaration subsequent to the attack involved various factors. After the war, this was filed as one of the important charges made by the Far East International Military Tribunal. To this day, even after this country has regained her sovereignty, some people still seem to entertain doubts about it.

The indictment filed in the Far East International Military Tribunal included three categories of charges: first, offense against peace (charges 1 to 36); second, offense of murder (charges 37 to 52); and third, ordinary war crimes and offense against humanity (charges 53 to 55).

To these charges, Mr. Kiyose, a lawyer representing the defense counsel, delivered a refutation in his introductory argument. He pointed out that the Potsdam Declaration stated in Article 10 that “we do not intend that the Japanese shall be enslaved as a race or destroyed as a nation, but stern justice shall be meted out to all war criminals, including those who have visited cruelties upon our prisoners.” Accordingly, the terms laid down at Potsdam, as Kiyose asserted, “constituted the only grounds for the war crime tribunal. Since Japan accepted that Declaration because she was defeated in the Pacific war, the crime tribunal should be limited to those crimes committed in the course of that war, but not to such cases in 1928 as were included in the indictment.” With the addition of six other points, Kiyose concluded that those seven points should be beyond the jurisdiction of the Military Tribunal. As one of those seven points, Dr. Kiyose strongly insisted that the offense of murder should not exist in war itself—not only from the legal aspect of International Law, but also from that of custom.

The offense of murder was from the beginning charged in the indictment, with the Pearl Harbor attack as its case in point. Since that attack was made without a declaration of war, it was unlawful in that it disregarded international law. The prosecution charged therefore that the attack constituted the offense of murder.

At 2:20 p.m. of December 7 (Washington time), Japan’s declaration addressed to the U. S. government was formally delivered by Ambassadors Nomura and Kurusu to Secretary of State Hull at the State Department. The orginal schedule called for its delivery at 1:00 p.m. (Washington time), which was 8:00 a.m. in Hawaii time, thirty minutes before the scheduled time of commencing the attack upon Hawaii.

As it turned out, due to a mishap the declaration was not delivered until 2:20 p.m. This caused the declaration, which should have been delivered thirty minutes before the commencement of the attack, to be given to the U. S. government about one hour after the actual attack. The prosecution charged that the attack launched before the delivery of the declaration was an unlawful one which constituted the crime of murder. The prosecution furthermore contended that the sending of the declaration was nothing but a trick conceived by the Japanese Goverment and the military, who had from the outset no intention of sending it before the commencement of the attack but used it as an excuse for their disregard of international law. The prosecution even branded it as the same kind of trick as the dispatching of Ambassador Kurusu to the United States just before the outbreak of war in an attempt to camouflage the intention of going to war.

If the Pearl Harbor attack was judged to constitute a crime of murder, many top military leaders at the time of the outbreak of war, including Admiral Nagano, would have to be indicted for the offense of murder. The development of the controversy accordingly was watched with keen attention by all Japanese officials.

From November to December, 1945, I was questioned about the Hawaii attack by Mr. Keenan and four other prosecutors. A surprise attack of itself cannot be censured, as it is a tactic which has been most ardently advocated both in Japan and abroad. The issue under dispute was whether the attack on Pearl Harbor violated international law by being launched without a previous declaration of war. Although I explained the situation in as much detail as I could, the prosecutors seemed to be prejudiced by their first suspicion, i.e., that the attack was a trick planned by the Japanese, who had no real intention of declaring war before the commencement of hostilities. Examinations on this point were also made of other persons concerned with the Pearl Harbor attack, but the indictment presented to the tribunal showed that the prosecutors refused to change their previous view. Prosecutor Higgins severely attacked the Hawaii Operation as treacherous.

All charges of murder (charges 37 to 52), however, were dismissed by the ruling that only offenses against peace would be subject to the judgment of the tribunal. In effect, the court made the decision that it had no jurisdiction in connection with the murder charge.

IX. Units Employed in Hawaii Operations

The operational units employed in the Hawaii Operation were divided into two groups, one being the Task Force with aerial attacks as its main objective, and the other being the Submarine Force for submarine attacks. Vice Admiral Chichi Na-gumo, Commander-in-Chief, First Air Fleet, was appointed as its over-all commander.

The units of the Task Force were organized as follows:

Units	Mission	Commander
1st Carrier Div.     (Akagi and Kaga) 2nd Carrier Div.      (Soryu and Hiryu) 5th Carrier Div.      (Zuikaku and Shokaku)	Aerial attack	Vice Adm. Nagumo C-in-C, 1st Air Fleet
1st Des. Sqd.      (Abukuma)      17 Des. Div.           (Tanikaze, Urakaze, Isokaze and Hamakaze)      18th Des. Div.           (Kastnui, Arare, Kagero and Shiranuhi)	Guard and Escort	Rear Adm. Sentaro Omori, 1st Des. Sqd. Commander
3rd BB Div.      (Hiei and Kirishima)	Guard and Support	Vice Adm. Gunichi Mikawa, 3rd BB Div. commander
8th Cruiser Div.      (Tone and Chikuma)
2nd Sub. Div.      (I-19, I-21, I-23)	Patrol	Capt. Kijiro Imaizumi, 2nd Sub. Div. commander
7th Des. Div.      (Akebono, Ushio)	Bombardment of Midway Island	Capt. Kaname Ohishi, 7th Des. Div. commander
1st Supply Train       (Kyokuto Maru, Kenyo Maru, Kokuyo Maru, Shinkiku Maru, Akebono Maru)	Supply
2nd Supply Train       (Toho Maru, Toei Maru, and Nihon Maru)

After completing their war preparation at the Kure Naval Station those 33 warships, consisting of six carriers, two battleships, two heavy cruisers, one light cruiser, eleven destroyers, three submarines, and eight tankers, left their bases in several groups during the period from November 10 to 18, 1941. By November 22 they had assembled at Hitokkap Bay, on the southern coast of Etorofu Island in the Kurile Islands. The crews for the first time were informed of their grave mission of launching attacks upon Hawaii, and they exhibited excellent morale. Presumably there had been no discovery of the plan by foreign agents.

On November 25, Yamamoto issued an order to the effect that “the Task Force will proceed to Hawaiian waters and, under a separate order to be issued later, operate in such manner as to destroy the U. S. fleet at the outset of war.” The order was supplemented by instructions calling for an immediate withdrawal of all Hawaii Operation forces in case diplomatic negotiations were successfully concluded between Japan and the United States.

At 6:00 p.m. of November 26, in a dense fog, the Task Force sortied from Hitokkap Bay into the Northern Pacific en route to its historic attack.

In conjunction with the movements of the Task Force, submarines of the Submarine Force were stealthily converging on Hawaii from other directions.

The Submarine Force was organized as follows:

Units	Mission	Commander
Katori (cruiser)	Flagship of 6th Fleet	Vice Adm. Mitsumi Shimizu, 6th Fleet Commander
1st Sub Sqd.     (I-9, I-15, I-17, I-25)	Blockade of Oahu and raiding operations	Rear Adm. Tsutomu Sato, 1st Sub. Sqd. Commander
2nd Sub. Sqd.     (I-7, I-1, I-2, I-3, I-4, I-5, I-6)	Same as above	Rear Adm. Shigeaki Yazazaki, 2nd Sub. Sqd. Commander
3rd Sub. Sqd.     (I-8, I-74, I-75, I-68, I-69, I-71, I-72, I-73)	Same as above	Rear Adm. Shigeyoski Miwa, 3rd Sub. Sqd. Commander
I-16, I-18, I-20, I-22, I-24)	Special attack unit*	Capt. Hanku Sasaki
I-10, I-26	Reconnaissance of key points	Comdr. Yasuchika Kashihara
* (Note: Each submarine of the Special Attack Unit took a midget sub on board.)

These 27 submarines, the cream of the Combined Fleet, had undergone the most rigid training over a long period. As the General Staff estimated the chance of a successful aerial attack by the Task Force to be fifty per cent, they considered it necessary to have the Submarine Force participate in the Hawaii Operation and launch underwater attacks coordinated with the aerial attacks. A plan was accordingly made to encircle Oahu Island with all available crack submarines simultaneously with the aerial attack upon the U. S. fleet in Pearl Harbor. These submarines were not only to sink enemy vessels confused by the aerial attack, but also to intercept enemy reinforcements and supplies from the West Coast. The submarines had to be sent to their assigned positions in advance of the Task Force in order to reconnoiter Hawaiian waters. That is why the submarine force was named in Japanese the Advance Force.

Among those responsible for the operation, I counted heavily on the activities of the Submarine Force. It was my belief that, even if the Task Force’s aerial attack ended in failure, the Submarine Force’s operation would not fail. My belief was based on the expectation that no hitch would arise in the submarines’ operations. They had a cruising radius of 10,000 miles, with no need of refueling at sea. Besides, submarines were best suited for stealthy movements, and a blockading operation of Hawaii would be very easy for the highly trained Japanese submariners. Furthermore, I expected that more damage would be inflicted by submarine attacks, which would be continued over a longer period, than by the air attacks, which would be of comparatively short duration.

The Submarine Force left Kure and Yokosuka between November 18 and 20, and proceeded to Kwajalein in the Marshall Islands, where the final refueling was carried out. Then they headed straight for their operational positions.

Thus, the Hawaii attack force proceeded eastward, the Task Force taking the northern course and the Submarine Force the southern. The strictest radio silence was maintained all the way.

On December 2 the famous code word telegram, “Climb Mt. Niitaka,” was received from Admiral Yamamoto. It meant that the data for opening hostilities had been set for December 8 as scheduled, and that the attacks would be made as planned.

No obstacles were encountered in the movements of any of the operational forces. The weather, which the General Staff and the operational forces feared most, eventually turned out favorably and the secrecy of the operation was safely maintained by the grace of Heaven. Although fear no longer existed that a change of plan would be necessary, there was one factor that we could not determine until the last moment. It was whether the U. S. fleet would be in Pearl Harbor at the time the attack was launched. If it was not there, nor within the limits of our attack radius after it had departed for maneuvers and training, the operational objective would be lost. By means of secret intelligence, designated as “A” information, we could learn of the daily activities of the U. S. fleet in Pearl Harbor until the day before the attack. The last information on the enemy which the attack force received was as follows:

“Received 2050, 7 December

“A” Information (issued 1800, 7 December)

Utah and a seaplane tender entered harbor the evening of 5 December.

Ships in harbor as of 6 December:

9 BB, 3 CL, 3 seaplane tender, 17 DD

In docks: 4 CL, 3 DD

All carriers and heavy cruisers at sea. No special reports on the fleet. Oahu is quiet and Imperial General Staff is fully convinced of success.”

This last information enabled us to expect with confidence the presence of the enemy fleet in the harbor, and therefore everyone concerned with the Hawaii Operation felt relieved. But, at the same time, it worried me that there were no enemy carriers in the harbor, upon which the utmost importance was placed. Not only would our force be unable to destroy them, but we might in turn be attacked by them. Judging from the activities of carriers and cruisers for several days, going in and out of the harbor, it was thought that they were at sea for training; but at the same time there was the possibility that they might be in Lahaina, a customary training anchorage. If so, it was estimated that those enemy carriers and cruisers would be discovered by submarine reconnaissance prior to the aerial attack, and that they could be attacked and destroyed by submarines even if the aerial attack failed to get them.

But actual events were entirely contrary to this estimate. Except for the USS Enterprise, which was then steaming 200 miles off Oahu Island, the carriers and heavy cruisers were far away in waters near Wake Island for training exercises against the Japanese. It was only learned after the war that the Nagumo Force, on its return to Japan after the attack, passed those ships at a distance of about 500 miles to the north. Had these forces met, the first engagement in history between carriers would have occurred.

X. Damages Inflicted

Although the “A” information of the day before the attack reported, as already mentioned, the presence of nine battleships, seven light cruisers, three seaplane tenders, and twenty destroyers in the harbor, there were actually eight battleships, two heavy cruisers, six light cruisers, twenty-nine destroyers, five submarines, one gunboat, nine minelayers, ten minesweepers, ten seaplane tenders, three repair ships, two oilers, two ocean-tugs, one hospital ship, one surveying ship, one supply vessel, one ammunition vessel, one submarine rescue ship, and one submarine tender—totaling 94 vessels in harbor when the air attack hit. As a result of the attack, six battleships were sunk, two others seriously damaged, one heavy cruiser and two oilers sunk. Heavy damages were also inflicted upon one heavy cruiser, six light cruisers, three destroyers and three auxiliary vessels.

Damages inflicted upon the enemy air force were no less heavy. The United States admitted that in the Pearl Harbor attack heavier damages were inflicted on the air force than on the surface force. Even though attacked by surprise, warships can retaliate, as they actually did, but planes lined up wing to wing were absolutely defenseless when attacked by surprise from the air. Maintenance crews and fliers at several bases on Oahu did all they could, and bravely fought even by mounting displaced airplane-machine guns on work benches and trash boxes. But most of the United States air force on the islands was destroyed before such make-shift defense measures became effective—99 Navy and 65 Army planes being thus destroyed and many others damaged.

As a result of the attack, a total of 2,403 Navy, Army, and civilian personnel were killed, and 1,178 wounded.

It was most noteworthy that all this damage was inflicted by the air attack, not by the submarine attack upon which much hope was originally placed.

In comparison to the damages inflicted, our attack force lost eight fighters, fifteen dive bombers, and five bombers. In addition, one flier was killed in a plane and several wounded. Seventy-four planes were holed. One submarine and five midget subs of the Submarine Force failed to return.

Few could doubt the tactical success of the Hawaii Operation after comparing damages inflicted on both sides. Dr. Morison’s criticism of the Hawaii Operation was focused on the point that the Japanese overlooked in the attack a greater victory which they could easily have gained.

When it is recalled that the success of this air attack upon Pearl Harbor nullified the U. S. Navy’s Rainbow No. 5 operational plan, and that it took two full years to recover its strength; further, that our forces, in the meantime, were able to complete without interruption the occupation of the Southern Resources Area, we, who are students of strategy, cannot agree with Dr. Morison’s criticism which assailed the tactics employed by the Japanese. In the event that the Japanese Navy had not launched the Hawaii attack and had consequently encountered the U. S. Fleet advancing on the Marshall and West Caroline Islands in pursuance to their Rainbow No. 5 operational plan, it would have been impossible for the Japanese Navy to have inflicted greater damage to them than they did in the Pearl Harbor attack, however favorable an estimate may be applied to the case.

Dr. Morison’s view maintains that, from the political viewpoint as well, the operation was a foolish one, for the attack incited the Americans to their slogan of “Remember Pearl Harbor.” Their firm determination to defeat Japan made the idea of a negotiated peace absolutely untenable to them. But does this really hit the nail on the head? While admitting that the Pearl Harbor attack really angered the Americans, it is yet inconceivable that their fighting spirit depended upon the point on which the first attack was made, since Japan in any case would have declared war, attacked U. S. forces, and occupied enemy territory. I cannot agree with Dr. Morison’s view.

XI. The Submarine Special Attack Unit

Everyone knows that the Japanese submarines were a total failure in the Pearl Harbor attack. There are many descriptions and discussions of the air operations at Pearl Harbor as well as of the Special Attack “Kamikaze” at the last stage of World War II, but there is almost no mention made of the Special Attack Forces’ midget submarines. For this reason I should like to describe their operations in particular.

Toward the evening of November 18, 1941, five large type submarines, i.e., I-16, I-18, I-20, I-22, and I-24 of the “special attack unit” under the command of Captain Hanku Sasaki left the Kure Naval Station under the cloak of secrecy and headed eastward. Each of them carried on board a secret weapon called “Target A” which was stored in a large tube on deck. These secret weapons were the midget submarines which tried to penetrate deep into Pearl Harbor on December 7 in conjunction with the air attack.

Incidentally, the midget submarine was not a weapon which was produced overnight for use at the Pearl Harbor attack, but a product of the tireless work of technicians over a period of many years. Back in 1933, a group of torpedo technicians got a hint from “A Sure Hit with Human Piloted Torpedo” advocated by Captain Noriyoshi Yokoo, who distinguished himself as one of the heroes of the Port Arthur Blockade Unit in the Russo-Japanese War, and started to study a method of “assuring a hit by releasing a torpedo piloted by one man from a mother torpedo.” For security reasons, this mother torpedo was named “Target A,” and it was this midget submarine which participated in the Pearl Harbor attack.

Why, then was such a weapon produced? The mission for a long time assigned the Japanese Navy since the establishment of the national policy in 1909, was to safeguard the national security with inferior strength against the superior strength of our potential enemy, the U. S. Navy. All aspects of strategy, tactics, preparations, education, and training had since then been concerned with gaining a victory over the U. S. Navy as its principal objective. Particular emphasis was placed on the use of submarines and on long range torpedoes in a decisive fleet engagement as a method to be employed by our inferior naval strength. A weakness inherent to the submarine was her slow submerged speed, a disadvantage which often made her miss an opportunity to attack. The limited range of torpedoes also often made them unsuccessful in attacks. The answer to the problem of how to utilize the advantages of both submarines and torpedoes and overcome their defects in a decisive battle materialized in this “Target A.”

Its characteristics, which showed a considerable enlargement over the early types, were in general as follows:

Total length	25 meters
Diameter	2 meters
Underwater displacement	50 tons
Torpedo tubes	2
Torpedoes	2
Underwater speed	19 knots
Radius of action	Capable of making 8-hour run at low speed after 50 minute underwater run at 19 knots
Crew	Two

Its shape was a perfect enlarged replica of a torpedo, to which a small conning tower was attached. Midget submarines were successfully constructed about one year after work on them was started. Then the building of their three tenders, Chitose, Mizuho, and Nisshin, was begun with the object of using them in a decisive battle against the main body of the enemy’s forces. In the spring of 1941, the first test launching of a midget sub from the Chitose was successfully conducted.

Although those midget submarines were originally built for use in a decisive engagement, a study was conducted of various methods of employing them in other operations, and we became convinced that they could be effectively used against vessels at anchor in a harbor. Since studies and preparation for the Hawaii aerial attack were being made at that time, all “Target A” personnel ardently wished to volunteer for a special attack. Their requests were granted, and some eventually penetrated into Pearl Harbor on December 7. At the start of hostilities twenty midget subs had been completed, of which five participated in the Hawaii Operation as the special attack unit.

Since it was of primary importance for the Hawaii Operation that the aerial attack be successful, it was directed that those midget submarines would first lie in waiting outside of the harbor and then stealthily enter to make an attack after the initiation of the air strike. It was extremely difficult to determine the results of those midget submarine attacks because of the confusion which followed the aerial attack, and also because none of those five boats returned to report. But the Japanese military, and the people as well, believed in their success before the true facts were uncovered following the end of the war. These erroneous opinions were principally based on the fact that one of our submarines on watch outside the harbor entrance the night of December 7 observed a huge explosion inside the harbor at 2101 hours Hawaii time, and also on the fact that a secret message which stated “succeeded to make attack” was received from one of the midget subs at 2241 hours that night. According to records made public by the United States after the war, however, only two of them finally succeeded in entering the harbor and no torpedo hits were scored.

Similar attacks by midget submarines were later made in Sydney Harbor, Australia, and Diego Suarez, Madagascar Island. Recognition was given to each as a valiant and glorious act of warfare conducted in the name of special attacks and excelling all the former deeds of the so-called suicide bands.

In a strict sense, however, there was some distinction between the midget submarine special attack and those special attacks which were widely conducted toward the end of the war. The difference lay in the fact that a means for rescuing crews was provided in the midget sub special attack, while in the later attacks there were actual body crashes in which there was no hope of returning alive. This may clearly be understood by the fact that, when the plan of “Target A” was advanced in the early part of 1933, Fleet Admiral Prince Fushimi, then Chief of the Naval General Staff, gave his approval only after he was assured that “this weapon is not to be used for body-crashing.” When midget sub attacks were planned in the Pearl Harbor attack, Admiral Yamamoto, Commander-in-Chief, Combined Fleet, in like manner gave his consent to it only after he had his staffs exhaustively study the feasibility of rescuing crews of midget subs and their chances of survival. As a matter of fact, those midget subs possessed sufficient cruising radius to return to a safe point outside the harbor, after completing their attacks in the harbor. Upon reaching this point they were to be picked up by the waiting mother submarines.

But none of the ten men who participated in the attack expected to return alive. They were determined to hit by ramming themselves, their spirit being identical with that of later special attack units. Ensign Sakamaki, whose boat went aground outside the bay due to engine trouble, had the misfortune of becoming POW No. 1. Mr. Matsura Hashimoto, who was the torpedo officer of the I-16 which released Sakamaki’s midget sub outside of Pearl Harbor, wrote in his book titled I-58 Safely Returns to Base as follows:

“When Ensign Sakamaki’s personal effects which were left behind were checked, his hair and nails were found carefully wrapped up together with a letter of farewell addressed to his parents. Even the required postage was attached to the list of addresses to whom these keepsakes were to be forwarded. The balance of his money had been given to his boy. The special precaution he took to prevent matches (to be used for destroying his boat) from getting wet by wrapping them in oil paper was proof of the grim determination of this young officer who did not expect to return alive.”

XII. Strategy Pros and Cons

As previously stated, Dr. Morison severely criticized the Japanese aerial attack in that it committed a strategical blunder in selecting its targets. He even said that it was the height of folly for Japan not to have attacked land military installations, especially oil tanks, since much more damage would have been inflicted by setting on fire those oil tanks than by directing attacks on battleships in the harbor.

I think that if Vice Admiral Nagumo had executed two or more air attacks, no doubt he would have ordered those oil tanks and other military installations on land attacked. But Vice Admiral Nagumo had planned from the beginning only one wave of air attacks on Pearl Harbor, and he selected for his targets the direct battle forces rather than the indirect military elements, and decided to concentrate all air attacks on ships and planes. In my opinion Nagumo made the best choice of targets for the simple attack which he launched.

Another argument among military students both at home and abroad about this aerial attack is concerning the number of attacks. Why did the Japanese Air Force, blessed by such a rare opportunity, discontinue its attacks after launching only a single attack? Why didn’t it exploit the gains made by repeating attacks upon the enemy two or three times? These criticisms, in other words, meant that had the Japanese repeated their attacks several times for two days, as the U. S. task forces used to do later in the course of the war, almost all of the naval craft in Pearl Harbor, numbering one hundred, would have been completely destroyed, and land military installations also wiped out.

But I do not agree with this view. It was not before 1944, three years after the war started, that the U. S. task forces could gain control of the sea; by this time the Japanese Navy had lost its integral fighting strength tactically as well as strategically. The U. S. forces had become so powerful that they no longer encountered a rival enemy anywhere. There was no need for them to risk a surprise attack, as the Japanese Navy did in the Hawaii Operation. They could launch an attack in strength any time and anywhere they wished. To compare those attacks of the U. S. task forces with our Hawaii Operation, can only be called irrational.

No greater surprise attack could have been planned than the Hawaii Operation. Our estimate of the available strength and state of preparation of the American forces precluded any advance plan for launching repeated attacks lasting two or three days.

But a war situation is liable to undergo kaleidoscopic changes. To alter original plans to meet the actual situation of an engagement, therefore, is entirely left to the discretion of the commander in the area.

This criticism does not hit the mark. The fact that there were no enemy carriers in the harbor meant that enemy carrier-borne air forces might suddenly come out to attack our force while our planes engaged in attacking Pearl Harbor. Since our force achieved much greater results in its initial attack than had been expected, credit might even preferably be given to Nagumo’s wise decision to terminate the attacks instead of not going too far with them.

One thing which I regret is that Nagumo’s aerial reconnaissances over the entire area within the radius of his attacks were not sufficient. Since he had already been informed by the “A” information on the night before that there were no enemy carriers in the harbor, he should have conducted a thorough and close air reconnaissance over the whole area to locate targets of attack as well as to safeguard his own force from their attacks. Had such air reconnaissance been carried out, the Enterprise, which was then sailing within 200 miles from Hawaii, should have been discovered. I think that there would have been no occasion for criticism of Nagumo’s conduct in the Hawaii Operation if he had repeated the attack on Pearl Harbor just once more, while carrying out air reconnaissance over the entire area more closely. At the same time, it should be considered as going too far under the circumstances to repeat attacks more than three times.

Admiral Nagumo’s insufficient air reconnaissance around his force was not limited to this case only. In the Midway operation in May, 1942, he committed the same blunder, as a result of which the Japanese Navy sustained fatal damage and a crippling blow to subsequent naval operations. Although those facts were kept secret at the time in the interests of the war’s direction, they are now well known to the public.

A captain and senior staff officer of the Japanese Combined Fleet in 1933, Admiral Fukudome held a succession of important assignments. In 1939, as a rear admiral, he was Chief of Staff for the Combined Fleet under Admiral Isoroku Yamamoto. Attaining the rank of vice admiral in 1942, he was once more Chief of Staff, Combined Fleet, then Commander-in-Chief, Second Air Fleet, and finally Commander-in-Chief Tenth Area Fleet, Thirteenth Air Fleet, and First South Sea Fleet, concurrently.