Nagumo was still far from happy. In fact, the success of the second mock strike in the Secret Room intensified rather than allayed his worries. The exercise had breathed a semblance of life into a hitherto-abstract concept. Now he could really visualize it and comprehend the full impact of the scheme. Nagumo could invoke much plain common sense in support of his pessimism about the Pearl Harbor project. He could have pointed out—perhaps he did—that sound strategy consists in fighting battles one at a time and in a place promising the best chance of victory. He could also urge that a commander in chief has a duty to foresee the worst in any given situation and prepare accordingly.
In particular, he resisted the adoption of the northern route. “During the war games there was no stormy sea, so we could take the northern course. But when we go to Hawaii, it will be different,” he argued unanswerably. More than once during the maneuvers Nagumo tried to convey to Yamamoto the terrible hazards involved in the operation and the awful consequences should anything go wrong. On one such occasion Yamamoto put a friendly arm around Nagumo’s heavy shoulders and said in effect, “Don’t worry about the matter. I will take full responsibility.”1
Nagumo was no coward, and if ordered to carry out the venture, he would give it everything he had; but he was frankly horrified by the prospect before him. It was all very well for Yamamoto to play Atlas and carry a world of responsibility on his back, but he would be aboard Nagato in home waters while Nagumo would be poking into the eagle’s nest. Yamamoto could not raise sunken ships, reconstruct crashed aircraft, or bring dead men back to life. Nagumo’s obvious gloom prompted Fukudome to remark to him cheerfully, “If you die in this operation, special shrines will be built in your memory.”2
Doubts also beset Ogawa about the feasibility of the Pearl Harbor assault despite his long interest in the idea. He brought up a number of disquieting questions from the intelligence viewpoint. Could all the necessary data on American anchorage dispositions, defense installations, and Fleet movements be assembled, evaluated, and disseminated effectively? True, Naval Intelligence had a solid core of information on hand from Yoshikawa, but it seemed incredible to Ogawa that the Americans would not follow the stream to its source and dam it. Even if Japan’s special agent continued to operate unimpeded, would the Naval General Staff have a complete G-2 picture of Pearl Harbor on attack day? Could it relay it to Nagumo somewhere in the northern Pacific in time to make it count?3
No one knew the answers at this time. Nor could anyone ensure that the plan would not fall into the hands of an alert enemy agent at the last minute. To catch any hint of a clue which might indicate that the United States had received a tip-off about the proposed attack, the Japanese set up a tightly meshed intelligence screen to filter all newspapers, foreign and domestic, as well as radio broadcasts from abroad. They also set a constant watch on American and British military personnel in Japan.4 As Nagumo told Shimizu, echoing all their thoughts, “If this operation is not kept a secret, then it will fail.”5
On the very day the exercises ended, Fukudome reported to Nagano and Ito his considered opinion of the scheme: “It is an alarming risk.” He had thought so from the beginning and saw nothing in the Secret Room to change his mind. “Not only are there all the normal difficulties inherent in such a bold operation, but there are numerous unknown factors besides. If the task force should be badly damaged and several carriers sunk, the striking power of the fleet will be decidedly weakened and the Southern Operation placed in serious jeopardy. We must ask ourselves, ‘Can a plan of such magnitude be kept secret?’ If not, it has little chance of success, and the results very likely will prove fatal.”
Then, after pausing a moment to let his hearers digest this unpleasant thought, Fukudome went on. “Our ships’ limited radius of action and the necessity for refueling at sea pose still other difficulties. Nor have we any assurance that the intelligence requirements can be fulfilled. The problem there,” he explained, “is to maintain a continuous, accurate flow of information on the exact whereabouts of the U.S. Fleet at all times. And the bulk of the Fleet will have to be in or near Pearl Harbor on the day of the attack, which is problematical.”
His chief listened attentively to this frankly pessimistic estimate. When Fukudome had finished, Nagano remarked, “In case of war I do not favor launching operations as risky as Yamamoto’s proposal. I think it is best for the Navy to limit its plans and concentrate on capturing the southern regions.” Ito had little or nothing to say, although as time went on, he “took a negative view toward the Pearl Harbor operation.”6
The Operations Section could not have agreed more heartily. “When the war games ended, my staff was strongly opposed to attacking Hawaii,” said Tomioka. “In the first place, the idea cut across the grain of all our thinking and planning prior to that time. Secondly, as everyone agreed, it was a plan of tremendous complexity. Thirdly, Japan’s fate so completely depended on her fleet that we could not bring ourselves to accept the staggering losses we thought inherent in such an inadmissible risk. Lastly, we considered the Southern Operation of such importance that we did not want anything else to jeopardize its success.”7
Miyo substantially concurred with Tomioka and added some objections of his own: “We were convinced that if a good share of our air strength were allotted to the Pearl Harbor operation, there would not be enough planes left to carry out the war successfully in the south. Carrier forces simply had to be used there because simultaneous landings in Malaya and the Philippines demanded protection.”8
If Nagumo’s task force did somehow manage to reach a position to strike Hawaii, who could guarantee that results would justify the expenditure of so many men, so much time and fuel? Thus, the war games did not produce widespread reassurance throughout the Navy. To Tsukahara they seemed unrealistic and confusing. “I was in a deep fog the whole time,” he confessed to a colleague.9 Nor was the First Air Fleet staff entirely happy. Kusaka thought the war games entirely too theoretical. “The results depended too much on the various personalities of the umpires,” he remarked.10
To Yoshioka the exercises epitomized the Japanese penchant for shortsighted, self-indulgent thinking. He saw the umpires underestimate American strength and slant their decisions in favor of the Blue team. They even equated one Zero with three enemy planes. As an experienced pilot Yoshioka felt his hackles rise at such stupidity. But when he tried to bring up these points, he received a sharp admonition for his pains.
Time and again Yoshioka saw the activities of the Red Team arbitrarily restricted when they threatened to upset Blue’s planned movements as well as such acts of God permitted as the squall which miraculously blew up just in time to spare Nagumo’s task force all but token damage after the successful second mock attack. Yoshioka charitably decided that in view of the serious international situation and the clear prospect of war, the umpires were trying to avoid anything which might foster misgivings or feelings of inferiority. Indeed, the tendency to underrate the enemy characterized Japanese naval war games prior to World War II, and it took the stunning defeat at Midway to bring this unrealistic practice to a halt.11
Nevertheless, the exercises served a vital purpose. “The war games cut through the year 1941 like the sharp edge of a dividing line,” said Genda. “They clarified our problem and gave us a new sense of direction and purpose. After they were over, all elements of the Japanese Navy went to work as never before, because time was running out.”12
If Japan planned on going to war, it must do so soon or not at all. Only enough oil remained to carry through eighteen months of fighting, and every day the stock diminished. In general, Japan’s military leaders agreed that if they waited another six months, they might as well forget about it and admit defeat by default. Time and weather marched together. The First Air Fleet could not possibly be ready for war by October. It might perhaps reach combat capability in November, but not top efficiency. Yet Japan could not afford to wait beyond early December. By dead winter, northern Pacific conditions would prohibit a transoceanic strike. Weather also conditioned Japanese planning for the Southern Operation. The monsoons began in October and increased in intensity for two months. Little wonder that the Army wanted to start the ball rolling by the end of October at the latest.
Then, too, the possibility of fighting the Soviet Union motivated Japan’s military planners. Because operations in Siberia would be possible after the spring thaw, the top strategists insisted that the Southern Operation be completed by the end of March 1942. Inasmuch as Japan’s schedule called for conquest of the southern areas within 120 days after the outbreak of hostilities, the war had to begin not much later than December 1, 1941.13
Perhaps with the idea of allowing all concerned to blow off steam before they had to unite for better or worse, Fukudome and Ugaki called a highly secret conference to be held in the Operations Section of the Naval General Staff on September 24 for a frank and open discussion of the Pearl Harbor plan.14 It was not attended by Nagano, Yamamoto, Nagumo, or any subordinate commander. Several members of the Operations Section reinforced Fukudome. In addition to Ugaki, Kuroshima and Sasaki represented the Combined Fleet. In their official capacities these were the logical choices, but they were also the men best calculated to support Yamamoto’s project to the hilt. At this time Ugaki was not overly enthusiastic, but he had shatterproof convictions of the loyalty a chief of staff owed to his commander in chief. Sasaki conformed to the Genda pattern of a naval air power disciple and shared Yamamoto’s faith in the effectiveness of audacity. Kuroshima would never dream of opposing Yamamoto, regardless of how outlandish his wishes.
Nagumo sent Kusaka, Oishi, and Genda. He could depend upon Kusaka to present all the arguments against the madcap notion and on Oishi to back him up. He could not leave Genda out of a Pearl Harbor conference, so he kept one vote solidly in the “yea” camp and two among the “nays.”
This conference lasted the greater part of a day. Fukudome, who presided, opened the discussion. He took a rather neutral position, as befitted a moderator, saying nothing either for or against Yamamoto’s plan.15 Not so Kusaka. “Tactically the attack might succeed,” he stated, “but strategically the chances are limited.” In other words, while the strike might give Japan a temporary advantage, Kusaka doubted that it would bring about any measurable long-range advantages. He also pointed out that even a tactical victory would depend upon secrecy. The enemy might well sight and engage the task force at any point in the long voyage from Japan to Hawaii.
Kusaka further questioned whether Tokyo could take any diplomatic measure which would catch Washington off guard politically. Once more he stressed the primacy of the Southern Operation and the urgent requirement for air support of that gigantic enterprise. “I cannot agree to this risky Pearl Harbor plan,” he declared. Then he added philosophically, “Of course, if ordered, the First Air Fleet will carry it out with no complaints.”16
In complete agreement with Kusaka, Tomioka expounded on the risks inherent in the plan. He maintained his opposition to diverting attention from the vital push to the south.17 Kami followed his chief. With his keenly analytical mind, he outlined the proposed Hawaiian strike in terms of plus and minus. On the credit side, a surprise attack might get through because it would be very difficult for the United States to maintain a twenty-four-hour air patrol in all directions. Granted that the raiders achieved surprise, the enemy would no longer be in a position to launch a massive counterattack; therefore, the task force might escape with relatively little damage.
But Kami rolled up a frightening total in the red ink column. Refueling posed formidable problems, bombing alone could not inflict maximum damage to the enemy warships, the Americans could salvage ships sunk in the shallow waters of Pearl Harbor and put them back in to operation within a reasonably short time, and the risk of detection could not be ignored.18
For the benefit of the nonairmen, Genda explained that horizontal and torpedo bombers were dual-purpose aircraft and could interchange their missions. By using them all as torpedo planes, he hoped to sink eight U.S. battleships. In addition, fifty-four dive bombers could concentrate on carriers, sinking three of them, while the remaining dive bombers attacked the air bases on Oahu, pinning down American air power. This all-torpedo attack against battleships would be most effective if the Japanese found the U.S. Pacific Fleet at Lahaina. Not only did Lahaina offer the raiders wide maneuvering space, but any vessel that plunged into Lahaina’s depths would be gone forever. For these reasons the Japanese hoped to the very moment of attack that they would discover at least a portion of Kimmel’s fleet in the Maui anchorage.
Genda’s every instinct urged the all-torpedo tactic, but he knew that torpedo results so far had been disappointing and that Nagumo’s pilots and bombardiers were still trying everything possible to improve their techniques. Would their best be good enough? Genda had to face the possibility that it might not. Therefore, he presented his colleagues with an alternate plan: the conversion of torpedo planes into high-level bombers and the execution of an all-horizontal-bombing attack in concert with a dive-bombing strike. He estimated maximum results from this method as about five capital ships—two or three battlewagons and three carriers.
While such losses would deal the enemy a considerable initial blow, it never occurred to Genda to settle for second best. He saw only one answer: Torpedo bombing was absolutely necessary. He realized that the difficulties were real and weighty, but he believed that intensive study and hard training could overcome them.19
Next, Oishi had his say. He saw eye to eye with Nagumo and Kusaka. He confined himself almost entirely to surface problems. “If enemy scouts go no further out than 300 miles, it will be easy to pick a course,” he said. “But if they go 400 miles or beyond, it will be difficult.” He particularly fretted over refueling, especially of the destroyers, which would require many transfusions to reach Hawaii. The larger ships could get along with only one. “Navigation and refueling in the heavy northern seas will be so complicated and difficult in themselves that the operation cannot possibly succeed,” he announced gloomily.20
Sasaki had studied long and thoroughly the possibility of the enemy’s discovering the task force en route. “If we have to take the southern course, we should abandon the operation,” he said. Impatiently he snapped his conclusion: “We could talk forever about a surprise attack; we should make up our minds and be done with it.”21
The meeting then turned its attention to the date for X-Day. By that term these officers did not mean that on a certain date the Emperor would declare war, whereupon Nagumo’s task force would leave Japan headed for Pearl Harbor. X-Day would find his ships already in position some 200 miles north of Oahu, ready to launch their planes.
“It is desirable to set up X-Day around November 20,” Fukudome told the group. “We have already lost our chance for a strategical surprise,” he said. “An attack such as the German Army made is no longer possible. We can only try to achieve tactical surprise.” So he thought it absolutely necessary to secure the southern area as soon as possible and to “prepare for eventualities with Soviet Russia.”
X-Day hinged upon the operational readiness of the First Air Fleet, and Kusaka knew all the bugs still remaining in his organization. “From the viewpoint of training itself, November 20 is too early,” he said point-blank.
This announcement jolted Ugaki. Shortly after the war games the Combined Fleet staff had agreed upon November 21—a Friday—as a tentative attack date. But on second thoughts Yamamoto and his officer preferred to launch the strike on a Sunday morning, when a maximum of American ships should be at anchor. X-Day thus would be neither November 16, as used in the war games, or Sunday, the twenty-third. If they had to postpone X-Day until around mid-December, reasoned Ugaki, all the more important for Japan to “make the surprise attack against Pearl Harbor at the very outbreak of the war from the point of view of overall operations.”22
Kuroshima did not speak until the end of the conference. At last, thoroughly disgusted with the opposition, he spoke up, strongly urging the adoption of Yamamoto’s plan “to assure the success of the Southern Operation.”23 Fukudome had the last official word. “From the political standpoint, the United States probably will keep its Pacific Fleet in Pearl Harbor, but there is always a possibility that it will return to the mainland for operational preparations.” He ended with a brief summary of the major problems involved in the strike against Hawaii, promising, “These will undergo serious study by the General Staff so that a final decision can be made as soon as possible.” As the meeting broke up amid the scraping of chairs and hum of conversation, Kuroshima remarked sarcastically to Genda, “Talking about operations doesn’t do the fighting!”24
When Kuroshima reported back to Nagato he gave his chief a blow-by-blow description. When he had finished, Yamamoto shouted in an explosive fit of temper, “Who called this foolish meeting? What’s the idea behind such babbling? Does anyone think for one second that we can carry out the Southern Operation without first crippling the American Fleet? As Commander in Chief of the Combined Fleet, I will take full responsibility for my plan!”25
Admiral Isoroku Yamamoto, Commander in Chief, Combined Fleet.
VADM Chuichi Nagumo, Commander in Chief, 1st Air Fleet. VADM Mitsumi Shimizu, Commander in Chief, 6th Fleet (Submarines). RADM Tamon Yamaguchi, Commander in Chief, 2nd Carrier Division.
RADM Chuichi “King Kong” Hara, Commander in Chief, 5th Carrier Division. (Official U.S. Navy Photo). Admiral Osami Nagano, Chief, Naval General Staff. (Official U.S. Navy Photo).
Admiral Harold R. Stark, Chief of Naval Operations. (Official U.S. Navy Photo).
Admiral Husband E. Kimmel (seated at right), Commander in Chief, U.S. Pacific Fleet; VADM Wilson Brown, Jr. (seated at left); Capt. William Ward “Poco” Smith (pointing), Chief of Staff, Pacific Fleet; Capt. Walter S. DeLany (standing), Operations Officer, Pacific Fleet.
Lt. Gen. Walter C. Short, Commanding General, Hawaiian Department. (United Press International Photo). Cmdr. Harold M. “Beauty” Martin, Commanding Officer, Kaneohe.
RADM Richmond Kelly Turner, Chief, War Plans Division, Navy Department (Official U.S. Navy Photo).
Admiral C. W. Nimitz assumes command as Commander in Chief, Pacific Fleet, December 31, 1941. (Official U.S. Navy Photo).
Operations Section, Naval General Staff, December 11, 1941. Front Row: Capt. Sadatoshi Tomioka, Chief of Section; Cmdr. HIH Prince Nobuhito Takamatsu; RADM Shigeru Fukudome, Chief, 1st Bureau; Capt. Shigenori Kami; Back Row: Cmdr. Nasatomo Nakano; Cmdr. Shigeshi Uchida; Cmdr. Sadamu Sanagi; Lt. Cmdr. Marquis Hironobu Katcho; Cmdr. Yugi Yamamoto; Cmdr. Tatsukichi Miyo.
RADM Takijiro Onishi, Chief of Staff, 11th Fleet. Cmdr. Minoru Genda, Air Staff Officer, 1st Air Fleet.
Lt. Cmdr. Shigekazu Shimazaki, Squadron commander, Zuikaku, leader of the second wave of the air attack on Pearl Harbor. Cmdr. Mitsuo Fuchida, Leader, air attack on Pearl Harbor. Lt. Cmdr. Shigeharu Murata, Torpedo bomber leader, 1st Air Fleet.