Akagi hummed with activity as key personnel from every ship crowded her wardroom at Nagumo’s call to attend a special conference on the morning of November 23. Here assembled the captains and staffs of the carriers, battleships, cruisers, and destroyers, Imaizumi and the skippers of his three submarines, and the commanding officer of Kyokuto Maru, flagship of the tankers.1
Nagumo opened the meeting with an electrifying announcement: “Our mission is to attack Pearl Harbor.” A wave of excitement ran through the assembly. This was the first time Nagumo had openly revealed the objective to all his commanding officers and staffs, although many present had been privy to the plot for months.
Nagumo explained that the attack was not yet an absolute certainty. If negotiations between the United States and Japan proved successful, the task force would be ordered back; otherwise, there would be no alternative but to carry out the strike.2 He appealed to each individual to do everything in his power to ensure the mission’s success.3
Next, Kusaka outlined the action they would take in case the enemy spotted the task force en route. If the enemy sighted the entire task force any time before X–1 Day, Nagumo would turn his ships back to Japan. But if he and his staff believed the Americans had discovered only a portion of the Japanese ships, the task force would change course as conditions directed and proceed. However, if the enemy found them on X-Day or fired on them prior to that date, the Japanese must perforce fight it out.4
Having made these remarks, Kusaka introduced each succeeding speaker. Oishi discussed the task force organization, the route across the Pacific, precautions to be observed, and the duty of each unit during the dangerous voyage. Then he explained the main points of Task Force Order No. 1, which Nagumo had signed that very day.5 It contained basic instructions for the task force covering passage to and from Hawaii and the overall aerial strike plan. Every officer present received a copy of this order and supplementary charts so that he could follow the ensuing discussions carefully. The order included this statement: “When the attacks have been completed the force will quickly withdraw. Upon returning to Japan the force will be re-equipped and supplied and then assigned a task in the Second Phase Operations.”6
So Nagumo, it would seem, officially set the pattern of the operation: a hit-and-run raid. But this requires an explanation. Nagumo and Kusaka thought that a powerful two-wave attack of more than 350 planes would be enough to deal the U.S. Pacific Fleet an “all-out fatal blow.” They could not conceive of the necessity for a second major strike. And they had reached this decision before the task force arrived in Hitokappu Bay.7
Even so, Nagumo issued another, seemingly contradictory task force directive on November 23—Operation Order No. 3. When the planes returned from their strikes against Oahu, this order stated, “preparations will be made immediately for the next attack. Carrier attack planes will be armed with torpedoes.
“If the land based air power has been completely knocked out, repeated attacks will be made immediately in order to achieve maximum results. However, if a powerful enemy force is in route to attack, subsequent attacks will be directed against it.”8 The idea of “repeated attacks” represented a concession to Genda and Fuchida.
Genda took the floor next, his exposition lasting about half an hour. “The primary objective of the attack is to destroy all U.S. carriers and at least four battleships,” he began. “A closely related objective is the annihilation of U.S. air power on Oahu.” He explained that the planes would concentrate initially on major fleet units. If they attempted to attack every vessel in Pearl Harbor, they would inflict only medium damage on any. And because of the shallow waters, the enemy could salvage moderately damaged ships within a reasonable time. That would nullify the main purpose of the operation: to immobilize the U.S. Pacific Fleet for at least six months.
Then Genda went into operational details. There would be two waves. The first, under Fuchida’s immediate leadership, would consist of fighters and all types of bombing planes. This would launch about 230 miles north of Oahu in time to attack at about 0800. The second wave under Shimazaki would consist of horizontal and dive bombers plus fighters. Launching 200 miles north of Oahu, it would administer the coup de grâce to ships damaged by the first wave and complete the destruction of U.S. air power beyond the ability to retaliate.9
After completing its mission, each wave would rendezvous about twenty miles northwest of the westernmost tip of Oahu. Thence the planes would return to their carriers, and the task force would begin immediate preparations to meet a possible counterattack. In case such a battle developed, all horizontal bombers would convert to torpedoes; if such a sea battle did not materialize, they might possibly launch a second major strike against Pearl Harbor. In that event they would convert the torpedo planes to horizontal bombers.
ORGANIZATION OF AIR ATTACK FORCE ON PEARL HARBOR
Next, Genda stressed the necessity for reaching Hawaiian waters undetected. No plane would launch until the morning of the attack; however, six fighters and three dive bombers must stand by on each carrier from sunrise to sunset to take care of any sudden contingency.10
Genda reiterated what Kusaka had already explained: If the enemy discovered the whole task force at any time before X–1 Day, the fleet would return to Japan. If U.S. aircraft challenged them before that day, they would shoot them down. But if such planes took no offensive action, the Japanese would let them alone. However, if enemy aircraft sighted the task force during X-Day, Nagumo’s men would attack without question.11
At this point Genda explained that according to plan, the Naval General Staff would keep the task force informed about the U.S. Pacific Fleet on the basis of reports from the consulate. Nagumo would receive word on the morning of the attack from scout submarines searching Hawaiian waters. Nevertheless, the task force had to have its own source of information in case the other two failed. It also needed a final report just before the attack so that Genda and Fuchida might make any last-minute changes in tactics.
Genda unveiled two tentative plans to accomplish these ends, both involving exceedingly grave risks. We need consider only the second, the one actually put into effect. The heavy cruisers Tone and Chikuma would each launch a seaplane exactly one hour before the first-wave takeoff. These scouts would reconnoiter Pearl Harbor and Lahaina Roads. Each pilot would determine whether U.S. ships were located in his reconnaissance area, ascertain the exact number of major units and their dispositions, check on weather and wind, and advise the task force accordingly.12 Nagumo and his staff recognized the dangers implicit in this arrangement. The scout planes took the chance of being sighted, and they would have to break radio silence to report. But Nagumo had to accept the calculated risk to reap the benefits of up-to-the-minute information.
Genda ended his discussion by describing the role of the fifty-four fighter-interceptors which would remain behind as a scouting and protective force. Each carrier would supply nine, and the total would be divided into three groups of eighteen planes each. One group would fly over the task force at all times, while the other two remained ready on the flight deck to take their turn or to act instantly in case of emergency. The first group would launch immediately after the departure of the second wave and would remain airborne for two hours. The second, then the third would follow in turn. Of each group, one flight of nine would patrol at 4,000 meters; the other, at half that altitude. These three interceptor groups would continue their mission until sunset of X-Day.13
Ono followed Genda to discuss communications during the coming voyage. He explained that radio transmission keys must be sealed and in some cases the fuses removed. Ships would receive messages but send none. Communications would be by flag in the daytime and by specially focused narrowbeamed blinkers at night, when strict blackout prevailed.14
Sasabe, Nagumo’s navigation and weather officer, then spoke briefly about the route to Hawaii and task force formations, of which the staff had worked out at least a dozen, depending upon the situation.15 At the end of the conference all in attendance drank to the success of the operation and toasted the Emperor.16
Immediately after lunch Nagumo held another meeting in Akagi’s wardroom. His own staff attended, as did Yamaguchi and Hara, with their staffs, and all the flying officers, headed by Fuchida. Nagumo opened this meeting by reading the instructions which Genda and Fuchida had prepared for him en route to Hitokappu Bay.17 When the young flying officers discovered that they would attack Pearl Harbor, “their joy was beyond description.”18
Then the airmen took over. Genda spoke for almost an hour. For the benefit of those who had not attended the first session, he repeated what he had said that morning.19 Then he analyzed the five major attack plans which he and Fuchida had prepared. They had worked out the plans with their flight commanders in Kyushu during September and October, so they were not pulling any major surprise. But they took full advantage of this last chance to rehearse, to coordinate group thinking, and to improve upon the design. Hitokappu Bay also provided the final opportunity to apprise Nagumo and his staffs of the manifold technical features involved in the forthcoming strike. Genda and Fuchida based their plans on five warrantable assumptions:
1. The U.S. Pacific Fleet would be in Pearl Harbor.
2. The U.S. Pacific Fleet would be in Lahaina Roads.
3. Part of the U.S. Pacific Fleet would be in Pearl Harbor and part in Lahaina Roads.
4. The U.S. Pacific Fleet would be at sea, and the task force would find it.
5. The U.S. Pacific Fleet would be at sea, but the task force would not find it.20
One need only discuss Plan No. 1, for that proved to cover the situation. The first wave, timed to strike Hawaii at approximately 0800, would consist of 189 aircraft: fifty horizontal bombers under Fuchida’s personal direction; forty torpedo bombers under Murata; fifty-four dive bombers under Takahashi; and forty-five Zero fighters under Itaya.
While Murata’s bombers sneaked in at low altitude to torpedo the capital ships, Fuchida’s high-level bombers would plaster their decks. Itaya’s fighters would dash in ahead of the main flight to seize control of the air, then in treetop-level assaults strafe the air installations. The dive bombers would concentrate on Hickam, Wheeler, and Ford Island, thus pinning down the U.S. fighters and bombers to prevent retaliation.21
The second wave would follow directly after the first, speed of execution being vital to the operation. This second wave would consist of fifty-four horizontal bombers under Shimazaki’s personal direction, eighty-one dive bombers under Egusa, and thirty-six fighters under Lieutenant Saburo Shindo. Torpedo planes would not participate because they should have fulfilled their mission in the first wave, and with the surprise factor gone, another torpedo attack would risk an unacceptable rate of loss from the now-aroused and outraged enemy.
All of Shimazaki’s horizontal bombers would attack Hickam, Kaneohe, and Ford Island, while Shindo’s swarm of Zeros strafed the same targets along with Wheeler, thus completing the destruction of enemy air power. At this time Genda entertained high hopes that Murata’s torpedomen would have capsized Kimmel’s lightly armored flattops. As they floundered helplessly, Egusa’s dive bombers would rip them so full of holes that salvage would be out of the question.22
After explaining all the alternate plans, Genda discussed preattack aerial reconnaissance: one patrol plane each from Tone and Chikuma to take off one hour before the first wave to scout Pearl Harbor and Lahaina respectively. He had scarcely finished when Murata jumped up with a strenuous objection. One hour between takeoff of the patrol craft and launching the first wave was too long, he insisted. The scouting flight was dangerous at best, and the period it covered in many respects the most critical of the entire operation. One hour, he maintained, might give the U.S. forces just enough time to discover the attack and prepare to repel it. Because so much depended upon surprise, he strongly urged that the time interval be cut in half.23
Murata’s recommendation touched off a spirited round of discussion. Although a few thought the full hour satisfactory, the majority sided with Murata. Genda appealed to Ono for his expert opinion as communications officer. Ono doubted that half an hour would suffice to put the message through. But Murata declared that surprise was the most important single feature of the entire attack plan. If they achieved it, they need not worry about the success of the operation. If they did not, who knew what fate might await them?
Genda wanted to consider all the possibilities before making his final proposals to Nagumo. He therefore asked the patrol flight officers if they thought the reconnaissance aircraft could overfly Pearl Harbor and Lahaina the morning of the attack without being discovered. They answered with an emphatic negative. Moreover, they agreed that the Americans would shoot down the patrol planes, an unpleasant prospect for the reconnaissance pilots of Chikuma and Tone, both of whom were in the assembly.24
Next, he asked Fuchida how late in his flight to Pearl Harbor he could receive the patrol plane’s report and still give his final attack orders to the first wave. Ever the realist, Fuchida replied that this would depend on the situation. But all things being equal, he would have to receive the report before his deployment order. This he would probably give a trifle before his lead plane reached the northern tip of Oahu, some twenty minutes before the actual attack. He emphasized that if his pilots did not know what was in the patrol report before they deployed, their bombing missions would probably suffer reduced effectiveness.
Despite the strong agreement among the flight officers that the time interval should be cut down, Genda temporarily shelved the problem so that the briefing might continue. To anticipate, the next morning he and Fuchida discussed the matter further, then recommended to Nagumo that the spacing be reduced to thirty minutes. After some deliberation Nagumo agreed.25
Once more Ono discussed communications. Again he stressed the urgency of radio silence, to be broken only in the sternest emergency. Not until Fuchida gave the final order for the attack could it be lifted, and then only for the flight leaders. His plan provided that if surprise were achieved, Fuchida would signal “Tora! Tora! Tora!” (“Tiger! Tiger! Tiger!”)26 Since any false move before that time could easily spoil the kill, each commander had his orders to refrain from any hostile act until Fuchida’s message from Hawaii flashed across the airwaves, for if anyone jumped the gun and tipped off enemy forces, he could easily ruin Japan’s overall plan. Japanese grand strategy everywhere had been based on the key factor of surprise, and all other operations carefully synchronized with the Pearl Harbor attack. Ono had arranged for one exception to the rule of radio silence: If a plane developed engine trouble, the pilot could send in his location.
Even after the assault was under way, Ono emphasized, radio messages must be kept to a minimum, both to avoid unnecessary confusion and, above all, to protect the location of the task force. However, in case any pilot lost his way on his return to his carrier, he could transmit a request for instructions. Ono was working on a special code for use in such an emergency.27
No sooner had he finished than Lieutenant Takehiko Chihaya, leader of the Eleventh Dive Bombing Group in the second wave, bounced to his feet. “I object to this plan of breaking radio silence no matter what the reasons might be at the moment of such a decisive battle which is do or die for Japan,” he protested. Turning to the pilots, he challenged them: “What about this? Why don’t we die in silence if our engines conk out?” He also insisted that the carriers should not reply to any appeal for help even after the attack. Such action would only aid the enemy in locating the task force, thus risking the success of the mission and the lives of everyone aboard the ships. The others agreed to a man that they would rather perish than break radio silence.28
That important point settled, Suzuki followed Ono as speaker. He gave a brief synopsis of the report he had delivered to Nagumo and his staff the previous evening. A short discussion then ensued on intelligence matters.29
One theme ran through the afternoon briefing and formed the framework of all five plans: Destroy the U.S. Pacific Fleet “wherever it might be found.” In particular, smash Kimmel’s carriers beyond all possibility of reclamation. From Yamamoto on down, the Pearl Harbor planners knew there would be no security for Japan’s widespread forces as long as American naval aviation was on the prowl in the Pacific. They saw Pearl Harbor as merely the scabbard for the shining, deadly sword of United States sea power which Nagumo’s task force must shatter before it flashed out to sunder irreparably Japan’s dreams of Empire.