In order to accomplish the lightning strike that had been assigned to him, Admiral Yamamoto, as discussed, had concluded that he must first destroy the U.S. fleet based in Hawaii, as well as eliminate the American forces in the Philippine Islands. Other countries and colonies would fall in short order: Hong Kong, Thailand, Burma, Indochina, Malaya, Singapore, Borneo, Sumatra, Java, Celebes, and New Guinea, and including scores of small islands spread out across the Pacific, which would soon bristle with Japanese guns, troops, warplanes, warships, and fortifications ready to repel any attempt to retake the conquered region,* which would then contain half of the human population on earth. It was estimated by Japanese military planners that it would take four to six months to overrun all the desired objectives and consolidate the gains, and that this could be done before the United States and her allies could recover from Pearl Harbor and other disasters that the Japanese had in store for them.
The Pearl Harbor operation, however, was the key to the whole business. The U.S. Pacific Fleet and air force had to be put out of business, lest they interfere with the Southern Movement. As Yamamoto himself put it, “If we fail, we might as well give up the war.”
The man chosen to train and lead the air strike itself was Commander Minoru Genda, a thirty-six-year-old ace fighter pilot who had distinguished himself in aerial strategy and by planning mass bombing raids during the long war with China. A lean, handsome man with “piercing eyes,” Genda has been described as brilliant, and certainly was a man before his time in the Japanese navy. He has also been described as the Japanese Billy Mitchell,† being the first in Japan to advocate eliminating the idea of a navy built around battleships, instead organizing the navy around a fleet of fast aircraft carriers, which, concentrated in task forces of six or more, could carry the offensive thousands of miles from the Japanese homeland.6
After determining that the strike on Hawaii was risky, but that it “had a reasonable chance of success,” Genda set about persuading Yamamoto that his maniacal one-way strike was nothing more than wasteful suicide since it would deprive the navy thereafter of the services of its best and most experienced pilots. Yamamoto conceded Genda’s arguments, leaving the young commander to begin tackling the problems he foresaw. Among them were how to keep the aerial torpedoes from diving into the shallow mud bottom of Pearl Harbor and how to prevent the level bombers’ ordnance from exploding on contact with the heavily armored decks of the American battleships instead of plowing through and exploding below where they would do the most damage. Genda solved the first problem by installing wooden fins on the torpedoes, which somewhat controlled their running depth, and the second by the ingenious idea of converting big sixteen-inch battleship shells as bombs with reinforced noses to allow them to crash through the armor plating to the belowdecks before exploding.7
In September 1941 training began in earnest. Japanese pilots practiced daily on the Inland Sea with astonishingly low-level torpedo runs—in the process, frightening the daylights out of sampan fishermen—and dive-bombers perfected their craft by pulling up at the last possible moment to ensure accurate hits. Certain rocks sticking out of the sea were selected as practice targets for the high-level bombers because they approximated the size of the American ships. But at that time neither the pilots nor even the ships’ captains knew what all this training was about; the ultimate mission was still privy to only a handful of trusted staff officers.
Meantime, Genda had concluded that merely to destroy the U.S. Pacific Fleet was not good enough. His fertile mind conceived an even bolder stroke—landing troops and occupying Hawaii itself, for with it would come Japanese control of the entire Central Pacific. After all, he reasoned, what was America going to do about it, with its fleet at the bottom of the ocean? But Genda’s superiors shot down his idea on grounds that what with the war still going on in China and their huge Southern Movement on the horizon, there were simply not enough troops or transports, they told him, to support such a vast expansion of the original plan.8 It is clear that Genda’s proposal had much to recommend it. If the Japanese had occupied Hawaii it would have created almost unimaginable problems for the Allies in the Pacific war. Hawaii was and would become the great American staging area for the future operations against Japan, and if the U.S. fleet had been forced to operate from the West Coast or even Australia, this could have prolonged the war by years. Even the use of the atomic bomb would probably have been set back because the Americans would have had trouble getting in close enough range of Japan to drop it.
Not everyone in Japanese military circles was as sanguine as Yamamoto about success in eliminating the U.S. Pacific Fleet in the manner prescribed. Naval war games had indicated that the Americans might be able to sink at least two of the carriers, and there was also the ever tricky question of achieving surprise, without which the raid might become a disaster. Then there was the thorny possibility that the U.S. fleet might be somewhere other than Pearl Harbor when the Japanese attackers arrived. For his part Yamamoto clung to his plan like a bat to a cliff; when pressed against the advisability of the attack by the navy’s general staff the much revered commander threatened to resign, effectively ending any opposition.
In order to forestall the obnoxious possibility that the U.S. fleet would not be lying at anchor in Pearl Harbor when the Japanese struck, the Imperial Navy general staff had installed itself a spy to operate out of the Japanese consulate in Honolulu. Takeo Yoshikawa, a twenty-nine-year-old graduate of the Japanese naval academy, had been dropped from the service because of a stomach ailment caused by heavy drinking but was later reinstated and sent to intelligence school. Using the alias Tadashi Morimura, Yoshikawa arrived in Honolulu harbor aboard a Japanese ocean liner in March 1941, looking like a tourist complete with a lei around his neck, and went to business under the phony cover of being an employee of the Japanese consulate.
He soon set up operations in a Japanese teahouse overlooking Pearl Harbor, where he used a telescope to count the number and location of American ships and track their movements to and from the ocean on fleet maneuvers. Yoshikawa used various ploys and disguises to get the information requested of him by his controllers back in Tokyo. A few times he disguised himself as a laborer in a sugarcane field to get a better look at the Pearl Harbor defenses. Mostly he just wore one of his garish Hawaiian shirts and cruised around the area either in a taxi or in a car provided by a sympathetic Japanese immigrant. Often he took with him a geisha girl from one of the several teahouses he favored; on one occasion he chartered a small single-engine plane to get a better view of the U.S. military installations. As well as the ship dispositions at Pearl Harbor, Yoshikawa noted on his aerial excursion the number and types of warplanes and runways at Wheeler and Hickam Fields and the Kaneohe Naval Air Station, in the process becoming, in essence, the proverbial fly on the wall. Once, when asked by his superiors to find out if the U.S. Navy used an antisubmarine net at the entrance to Pearl Harbor, Yoshikawa dressed up as a fisherman complete with cane pole and after dark slipped into the murky waters to try to find the net. He was unsuccessful, apparently due to nervousness.
However, flush with an expense account from his Tokyo handlers, Yoshikawa’s old habits of drinking and womanizing soon returned and before long he found himself in bitter arguments with the senior consular staff, who were concerned that his behavior would create suspicion by American coun-terintelligence agents, which it did; at one point he was arrested by Hawaiian police for public drunkenness. In fact Yoshikawa had been under surveillance by U.S. authorities from the moment he stepped off his ship; the Office of Naval Intelligence and the FBI had noticed that even though he was listed as a diplomatic “chancellor,” there was no record of him ever having served in any Japanese diplomatic post. He was tailed and his phone wiretapped, but nothing extraordinary turned up. The U.S. agents certainly suspected Yoshikawa of spying, but there was little they could do about it since he was shrewd enough not to break any U.S. laws such as taking photographs or actually enter
ing any military facility. Besides that, he was with the consulate and it was “sacrosanct,” according to an FBI agent assigned to the case. And finally, according to the State Department, any move to deport Yoshikawa might have revealed to the Japanese that the United States had broken into their top-secret diplomatic message system.9
Then, as luck would have it, barely two months before the Pearl Harbor attack, Tokyo sent a message ordering Yoshikawa to draw up a specific plotting grid for every U.S. warship in Pearl Harbor, dividing the anchorage into five subareas known as A-B-C-D-E, and wanting to know such things as whether two or more ships were moored side by side at the docks (vital information for Genda and his planners because the inboard ship or ships would be impervious to the aerial torpedoes).
This message was, naturally, intercepted via MAGIC and in due time it was decoded and translated and wound up on the desk of Colonel Rufus Bratton, chief of the Far East division of army intelligence in Washington, D.C. It especially attracted Bratton’s attention because for the first time in his experience the Japanese were showing curiosity as to the precise location of U.S. ships at Pearl Harbor, and not just when they came and went. Unfortunately, Bratton’s superiors did not share his interest in this obviously noteworthy request from Tokyo and before it was all over the “bomb plot message,” as it came to be called, would later trigger a firestorm of maledictions during the various hearings in Congress and elsewhere looking to assign blame for the intelligence failure at Pearl Harbor.10
Meantime, U.S. intelligence was doing some spying of its own, though perhaps not in as exotic a manner as the ubiquitous Japanese agent Yoshikawa. Six months before the Japanese attack the U.S. Navy had detached Commander Joseph John Rochefort from his duties as intelligence officer of the U.S.S. Indianapolis and told him to take charge of what he would rename the Combat Intelligence Unit at Pearl Harbor, which was responsible for snatching Japanese radio waves and decoding them. The forty-three-year-old Rochefort was a wise and obvious choice for the navy, since he was the only man in the entire service who was an expert in radio, cryptology, and the Japanese language.
As we know, the MAGIC system had already broken the Japanese diplomatic code, but breaking the Japanese naval code was a different problem entirely. Still, Rochefort set at it with a vengeance because he understood that he now had perhaps the most crucial single job in the Pacific: keeping track of the Japanese navy. Rochefort employed about a hundred people—most experts in one field of radio intelligence or another, some headquartered in a windowless, airless basement of an office building. He himself was something of an eccentric; he lived almost exclusively in this dank chamber and his working uniform consisted of a red satin smoking jacket and carpet slippers.
Rochefort’s section worked around the clock trying to crack the Imperial Navy’s code but with little success; up until the end of November 1941, they had managed to decipher only about 10 percent of it. But there are other ways to skin a cat; for instance, they were often able to identify the regular telegrapher aboard certain Japanese warships by his particular touch on the telegraph key. For example, the radio telegrapher aboard the Japanese carrier Akagi, according to the U.S. fleet intelligence officer, “played that key as if he were sitting on it.” Thus armed with the identity of a particular ship, Rochefort’s section was then often able to locate its position by radio direction finding. This was an intelligence-gathering system in which stations of specialists were set up across the far reaches of the Pacific, from Hawaii to the Aleutians to the Philippines to the Dutch East Indies, to intercept radio traffic from the Japanese fleet. They would home in on a signal until it was at its loudest and then take a bearing. If two or more direction finders were able to home in on the same signal, they could fix the exact position of that ship and, in fact, track its course and speed by continual interceptions. It wasn’t as good as being able to decipher the message itself but, at least so far, Rochefort was able to keep track of where the Japanese navy was, if not what it was up to.11
Then at the end of November 1941, an ominous development took place; the Japanese navy suddenly changed all of its call signals. Until then, Rochefort and his section had reliably placed the fleet—especially the carriers—in Japanese home waters, primarily in the Inland Sea. Even more ominously there was a noticeable drop in radio traffic. Now Rochefort was in the dark and promptly reported this to his boss, U.S. Pacific Fleet intelligence officer Edwin T. Layton, who promptly reported it to his boss, Admiral Husband E. Kimmel, commander in chief of the Pacific Fleet.
Kimmel immediately ordered Layton to prepare a paper on what currently was known about the disposition of the Japanese navy. When Layton delivered it next day, Kimmel was shocked to read that there was no information whatever on two full Japanese carrier divisions.
“What!” he demanded. “You do not know where they are?”
Layton replied that Rochefort’s intelligence people still thought they were in home waters, but could no longer be sure.
“Do you mean to say,” the admiral asked incredulously, “that they could be rounding Diamond Head and you wouldn’t know it?”
That was about the size of it, but Layton managed a lame reply: “I would hope,” he told the Pearl Harbor commander, “that they would be sighted by now.”12
All through the autumn of 1941 the negotiations between Tokyo and Washington had continued at an agonizing snail’s pace. Part of the problem was the translations provided to Secretary of State Hull by the MAGIC people who, of course, were reading Japan’s top-secret messages to its Washington ambassador. The difficulties of precise translations from Japanese to English have been noted in the previous chapter, but here are some concrete examples. The Japanese foreign minister cabled Ambassador Nomura that he must persuade Hull and Roosevelt to accept Japan’s A or B proposals because “THE SECURITY OF THE EMPIRE DEPENDS ON IT.” The people over at the MAGIC shop, however, translated the intercept as saying: “IN FACT WE GAMBLED THE FATE OF OUR LAND ON THE THROW OF THIS DICE.” Further, Tokyo informed Nomura that “THIS IS OUR PROPOSAL SETTING FORTH WHAT ARE VIRTUALLY OUR FINAL CONCESSIONS.” But what Hull read in translation was: “THIS PROPOSAL IS OUR REVISED ULTIMATUM.”13
True, the general sense in both these examples—and there are many others—is essentially the same, but given the delicacy of the ongoing crisis, every nuance had added meaning, and it too often appears that the American translators went for the more “interesting” and direct version. In the end, the result would probably have been the same, but it is perhaps unfortunate that Hull seemed to be getting the more strident renditions of Japan’s political stances.
By the end of November 1941, matters were fast coming to a head. It had become obvious to the U.S. military commanders, General Marshall and Admiral Stark, that war with Japan was simply a matter of time, and that the U.S. Pacific possessions might be struck with terrible suddenness. Secretary of War Stimson recorded in his diary that President Roosevelt had decided (for political reasons peculiar to the American voting population) that if war did come, it was desirable that Japan fire the first shot, so to speak. In other words, that the United States should be the one attacked, not the other way around. This was never to suggest that American commanders in the Pacific leave themselves open and defenseless for a crushing blow, but many of the so-called revisionist historians have interpreted it as such in the race to blame Roosevelt and others for deviously plotting the disaster at Pearl Harbor.
Mistakes were made, to be sure, and afterward heads rolled, though perhaps not the right ones. For more than a week as autumn turned to winter, a high drama began to unfold between Washington and its outposts in the far Pacific. On November 27, 1941, after Secretary of State Hull’s peremptory reply to Japan’s peremptory response to his previous note, the Japanese concluded that negotiations were over and, in any case, they already had their carrier fleet skulking toward Pearl Harbor. And so on that date Admiral Stark issued his now famous “war warning” message to naval commanders in the
Pacific, and Stimson issued a similar one to the army commanders, suggesting that the Japanese might break out hostilities “within a few days” and reiterating the business about not attacking the Japanese first.
Unfortunately, neither of these messages even hinted that an attack might be imminent on Pearl Harbor itself. Instead they suggested—reasonably—that Japanese movements would probably be against the far-off Philippines or targets farther south such as Malaya. In Hawaii the senior U.S. Army commander, General Walter Short, was warned by officials in Washington that sabotage seemed his greatest danger because of the large number of Japanese, both native and American-born, living in the islands. General Short reacted by ordering that all military aircraft at the major bases be lined up wingtip to wingtip on the runways to make guarding them easier against saboteurs. It also, of course, made them perfect targets if an attack came from the air rather than from the ground.
After much last-minute internal squabbling as to whether or not to actually provoke war with the United States, the dictator Tojo, the emperor, and various other high functionaries decided to let war plans go ahead. Accordingly, they proposed a response to Secretary of State Hull’s last note to them. It was basically a long screed that ticked off everything they didn’t like about the United States of America. It was ordered sent to the Japanese ambassador in Washington in fourteen parts, the first thirteen to arrive on Saturday, December 6, and the final part to arrive on Sunday, December 7. Tokyo further instructed its ambassador that after the full message was received, he was to see to it that all major codes and code machines in the embassy were destroyed.