Like Fletcher’s lonely vigil in the Coral Sea, the strategic situation in early April for the whole of Nimitz’s Pacific Fleet was one of watchful waiting. The few in the know intensely anticipated the Cominch-inspired Tokyo raid. Crammed with sixteen army B-25 medium bombers, the Hornet sailed on 2 April from San Francisco as part of Captain Mitscher’s TF-18 (one carrier, one heavy cruiser, one light cruiser, four destroyers, and fleet oiler) bound for a distant North Pacific rendezvous with Halsey’s TF-16 (Enterprise, two heavy cruisers, four destroyers, and fleet oiler) coming out from Pearl. Pye took command of the seven old battleships of TF-1 at San Francisco on 4 April, while Fitch, the new CTF-11, waited until mid month for the Lexington to emerge from the Pearl Harbor Navy Yard after necessary upkeep and replacement of her four 8-inch gun mounts with many light automatic antiaircraft weapons.1
In early April following the annihilation of the ABDA forces in the Dutch East Indies, two powerful Japanese task forces stormed the Indian Ocean. They included five carriers from Admiral Nagumo’s Kidō Butai (less the Kaga under repair in Japan), light carrier Ryūjō, four fast battleships, nine cruisers, and seventeen destroyers. Nagumo set his sights on naval forces and land-based air on Ceylon, while the second force swept the Bay of Bengal of shipping. The newly reconstituted Eastern Fleet under Adm. Sir James Somerville comprised only five old battleships, three carriers (including venerable Hermes) with inferior aircraft, seven cruisers, and fourteen destroyers. Radio intelligence warned the wary British of an incursion into the Indian Ocean, but not one of such strength. Somerville expected perhaps two carriers and some cruisers to appear on 1 April. He advanced to meet them but found nothing. When Nagumo’s forces finally turned up on 4 April, Somerville had already pulled back. The next day Nagumo raided Colombo on Ceylon and pummeled two heavy cruisers. Somerville bravely positioned his striking force south of Ceylon, but his only viable option was a night carrier torpedo strike. It proved too difficult to move into range without the risk of being pounded in daylight by the Japanese carriers, so he retired southwest to Addu atoll in the southern Maldives. On 9 April Nagumo struck Trincomalee on Ceylon and sank the unfortunate Hermes before she could get clear.2
Nagumo withdrew on the evening of 9 April well satisfied with the mayhem inflicted at the cost of only seventeen aircraft. The British lost five warships and twenty merchant ships. Nagumo did not attain his primary objective, the destruction of the Eastern Fleet, but he certainly took the wind out of its sails. The Eastern Fleet withdrew to African waters and for nearly two years only played a modest role in the war against Japan. In turn the Japanese never followed up their success in the Indian Ocean, which could have disrupted the British defense of the Middle East and offered the best chance for an Axis triumph. Conversely, had Admiral Yamamoto committed to the southwest Pacific just a portion of the forces used in the Indian Ocean, Admiral Inoue’s South Seas Force would have rolled over Fletcher’s TF-17 and swiftly gained all of its objectives. When Japan got around to advancing to Port Moresby and the Solomons, it would not be so easy.
Once the British realized the magnitude of force arrayed against them in the Indian Ocean, they again beseeched Washington for swift action in the Pacific. Churchill chided Roosevelt on 7 April that Nimitz “must be decidedly superior to the enemy Forces in the Pacific” and urged he cash in on this “immediate opportunity.” King told Pound that “measures already in hand [are] ordered to be expedited,” and that they “should tend to relieve pressure in critical area.” However, he was not about to offer any details. King intended Pye’s TF-1 to operate in concert with Fitch’s TF-11 (Lexington) in the central Pacific, but before then, the bombs dropped on Tokyo should yank Japanese attention out of the Indian Ocean. At the same time Fletcher’s isolation in the face of the enemy buildup in the southwest Pacific preyed on Nimitz’s mind, particularly as all of his other assets were tied up elsewhere. On 2 April he had McMorris’s War Plans Section look into using Fitch’s TF-11 to reinforce TF-17 in the South Pacific. On the eighth he suggested to King that TF-11 go south rather than chaperone the old battleships off Hawaii. On the way the Lexington could deliver marine fighters to Palmyra and Efate, which King greatly desired. Nimitz suggested that TF-1 sail on 14 April from San Francisco, exercise alone north of Hawaii, and then in early May either continue to Pearl or return to the West Coast. This message signaled a significant shift from previous Cincpac policy of retaining carrier strength in the central Pacific, but Nimitz soon ventured far beyond that first step. Concerned Halsey might need support should the enemy pursue the Tokyo raiders, King still wanted to join Pye and Fitch but directed that they meet down in the Palmyra–Christmas Island area a thousand miles south of Pearl. The Lex could deliver the planes to Palmyra. Consequently on 10 April Nimitz cut orders for TF-1 (seven battleships, seven destroyers) and TF-11 (Lexington, two heavy cruisers, and seven destroyers) to rendezvous on 22 April five hundred miles southeast of Hawaii and train west of the Palmyra-Christmas line. They would stay together until 4 May, after which the battleships, at least, would proceed to Pearl. Nimitz, however, would not drop the issue of getting TF-11 south to the Coral Sea.3
On 10 April Fletcher copied as information addressee another puzzling Cominch bolt from the blue. King apprized Nimitz that Vice Adm. Robert Ghormley would command the South Pacific Force. The last Fletcher knew of his classmate was Ghormley’s relief after serving briefly as commander of U.S. Naval Forces in Europe. Because Ghormley would need considerable time to take up his distant post, King suggested Fletcher be named acting South Pacific Area (Sopac) commander. His true intention may have been for Fletcher to go ashore to organize the headquarters and main operating base at Auckland, then fade away once Ghormley showed up. King did not say who would run TF-17 in the meantime, but of course only Poco Smith was available.4
Fletcher was unaware of the brawl in Washington, as King wrangled with rivals Marshall and Arnold over reorganizing the Pacific high command. On 2 March King proposed that the Anzac Area be greatly enlarged to include all the South Pacific island bases he needed for his anticipated offensive toward Rabaul. Anzac and its western neighbor ABDA would be integrated into a single command, with the rest of the Pacific divided into northern, central, and southern areas. He did not reveal that he fully expected to take personal command of this enlarged ABDA/Anzac Area. On 4 March he laid out a similar vision of the Pacific for Nimitz, who, at least “initially,” was to have only the North, Central, and South Pacific command confined to Fiji and waters north and east of there. King himself would handle ABDA/Anzac and the Southeast Pacific. Finally revealing a streak of independence, Nimitz countered on 6 March, asking for the Anzac, South Pacific, and Central Pacific commands for himself and leaving King the rest. Even before King read Nimitz’s emphatic reply, he found himself locked in a real dogfight in Washington. The Australian and New Zealand governments also favored an expanded Anzac Area that not only included their respective nations but also New Guinea and the old ABDA area. However, they had in mind as supreme commander not King, but General Brett, MacArthur’s deputy in Australia, who obviously just warmed a chair. Appalled he might lose control over his cherished South Pacific offensive, King complained such an arrangement “would cut across the whole system of command and operations in the Pacific Fleet.” In fact he proposed precisely the same thing with regard to Nimitz. Now King thought it imperative to separate Australia and New Zealand into an “Australian Area” and a “Pacific Ocean Area,” which would include New Zealand and the New Hebrides.5
Marshall watched benignly on 9 March as his own War Plans Division recommended to the Joint Chiefs that a new Southwest Pacific Area absorb not only ABDA but also extend as far eastward as longitude 170° west, gobbling up even Samoa. The respective Allied governments would then decide upon a supreme commander of the Southwest Pacific Area, doubtless MacArthur. Marshall got a rise out of King and gracefully gave in if the Philippines could be included in a much-reduced Southwest Pacific Area under MacArthur. The Pacific concerned Marshall far less than Europe, except to keep the U.S. commitment as low as possible. A greatly relieved King tasked his own War Plans Division to draft the proposal for the new Pacific organization. The Southwest Pacific Area under MacArthur (Supreme Commander, Southwest Pacific Area, or Comsowespac) would absorb the Anzac command, to be designated the Southwest Pacific Force under Leary (Commander, Southwest Pacific Force, or Comsowespacfor), while the navy received the Pacific Ocean Areas. The boundary between the two would cut between the Solomons and the New Hebrides. The president approved the arrangement on 31 March.6
On 3 April Nimitz learned to his pleasure he was to become commander in chief of the Pacific Ocean Areas (Cincpoa), made up of the North Pacific, Central Pacific, and South Pacific areas (a command he held concurrently with Cincpac). Given King’s reluctance to turn over real power to Cincpac, that alone was a major victory. Aside from defending his region and supporting MacArthur, Nimitz was to “prepare for execution of major amphibious offensives against positions held by Japan initially to be launched from South Pacific and Southwest Pacific Areas.” King being King, however, made things difficult and complicated by diluting Cincpac’s control over the crucial area. Nimitz received direct control of the North and Central Pacific areas but was to “appoint” the South Pacific commander. “Acting under [Cincpac’s] authority and general direction,” Commander, South Pacific Area and Force (Comsopac) would “exercise command of combined armed forces which may at any time be assigned that area.” Comsopac was a necessary political buffer between Nimitz and the supersensitive MacArthur, although it appears King also did not fully trust Nimitz alone to carry out his offensive. On 4 April King now told Nimitz merely to “nominate” the Comsopac, subject to Washington’s approval. Nimitz trotted out Pye, who had just taken over TF-1, and proposed Ghormley relieve Pye with the battleships. Well aware Pye might not be acceptable, he also offered Ghormley as an alternative Comsopac. His prudence was justified when Pye was rejected in favor of Ghormley.7
Ghormley was available due to a major command shake-up in Washington. Since 30 December Admiral Stark, the CNO, had worked alongside Cominch with little friction. King himself was willing to serve under him, but Stark wisely realized the perils of divided command. He offered his resignation on 7 March, and five days later Roosevelt combined the posts of CNO and Cominch in the person of King with unprecedented control over the navy. As reward for one of the main architects of the Germany-first strategy, Stark took over the newly established U.S. Naval Forces in Europe. Personally for Ghormley that was a shame. He served ably as special naval observer in Britain and looked forward to the European command. Well respected for his intelligence and diplomatic savvy, Ghormley made flag rank in 1938 as an assistant CNO, then traveled to London in the summer of 1940. Despite rising to vice admiral in October 1941, he had not held an operational post as a flag officer either ashore or at sea except, briefly, the European command. Still smarting over the failed Wake relief, Roosevelt would never agree to Pye as Comsopac. It had to be Ghormley, who was not altogether pleased to leave that theater for the other side of the world. In fact Ghormley was in over his head as Comsopac and might better have remained in Europe or accrued much needed seasoning as CTF-1.8
Nimitz also rebuffed King’s attempt to put Fletcher on the shelf. On 10 April he declared privately to King that it was “inadvisable repeat inadvisable” to name Fletcher as temporary Comsopac. That would be “incompatible with effectively operating his task force,” which “should be ready to counter prospective enemy moves and cover arrival of forces now en route advanced bases.” Nimitz also requested personal command of Sopac until Ghormley settled in and questioned the fuzzy command relationship that King set out between Cincpac and Comsopac. Originally Cincpac was to relinquish operational control of Pacific Fleet task forces assigned to Sopac. Nimitz much preferred to do that only when he desired and asked for similar latitude should his ships cross into MacArthur’s Southwest Pacific Area. On 14 April King gave Nimitz direct control of Sopac until Ghormley could take command but retained control over the establishment of the South Pacific bases. Nimitz did not mind. He had far more important things to consider: the safe return of the Tokyo raiders and prospects of a major battle in the Coral Sea.9
Nimitz’s firmer grasp of the reins of command coincided with a vast increase in the amount and value of the communications intelligence (comint) available to him. Hitherto the intense efforts to decipher Japanese naval traffic relied largely on traffic analysis—who was talking to whom—and the relative regional intensity of radio transmissions. That, along with old-fashioned combat intelligence (sighting reports, captured documents, and so on), yielded considerable insight into the changing enemy order of battle and facilitated broad estimates as to future activities. King and Nimitz particularly valued comint to forecast where powerful Japanese striking forces were likely to appear, so U.S. carriers could safely raid elsewhere. Such timid strategy would change drastically later in April, when Nimitz began spoiling for a fight.
There were several reasons why Allied radio intelligence improved so dramatically by early April. Foremost among them was the failure of the IJN to institute a timely change of its general purpose fleet cryptographic system, Naval Codebook D. Used in the vast majority of high-level naval radio messages, Codebook D consisted of a printed list of thirty thousand five-digit numbers, each of which stood for a unit designation, technical term, verb, and so on. Separate ciphers for dates, grid locations, and geographic place names also appeared within the messages. Before transmission, another series of five-digit numbers taken from a huge list of up to fifty thousand random numbers (the “random additive table”) were added to the original numbers as an enhanced cipher. Such a primitive system contrasted sharply with electrical cipher machines, such as the U.S. ECM (Sigaba) and the German Enigma, but it was formidable nonetheless. To the Allies, the version of Naval Codebook D in use at the start of the war was known as JN-25B. Prior to the war not a single JN-25B message was deciphered. Just prior to the war the IJN implemented another random additive table that caused great consternation for the cryptanalysts who tackled JN-25B after Pearl Harbor. In February, however, they realized it did not constitute a whole new codebook. The IJN originally intended in April 1942 to issue the wholly new Naval Codebook D1. However, delays in distribution postponed the changeover to 1 May and eventually to 27 May, with fatal consequences for Japan.10
While the Japanese continued to use an elderly code, the U.S. Navy took advantage by greatly improving its cryptographic efforts. Commander Rochefort’s Hypo team concentrated on JN-25B in concert with Station Cast (with Com 16) on Corregidor. In turn Cast spun off a separate cryptographic station (dubbed Belconnen after the Australian naval radio station near Canberra) under Lt. Rudolph J. Fabian, who set up shop in Melbourne in March under Leary’s Anzac command. In Washington Cdr. John R. Redman’s OP-20-G Radio Intelligence Unit (Negat), in the office of the chief of naval operations, redoubled its efforts against JN-25B and continued monitoring Magic, the Japanese diplomatic cipher. All three stations exchanged data and reviewed findings through a radio network known as Copek. The radio intelligence organizations fed comint to the intelligence officers of the several fleet commands for analysis and to brief their respective chiefs. Lt. Cdr. Edwin Layton handled that duty for the Pacific Fleet, with input from McMorris’s War Plans Section. An excellent Japanese linguist, Layton enjoyed a close personal relationship with Rochefort’s talented team. In turn Cincpac and Comanzac advised the task force commanders through daily bulletins supplemented with urgent special messages. In March the radio intelligence centers even began piecing together fragmentary texts of intercepted messages. It was tempting, but risky, to fill in all those tantalizing blank spots with informed speculation. Although one authority asserted there was “no indication that erroneous decisions were made based on the partial message texts,” inevitable inaccuracies in interpretation certainly occurred and did adversely affect command decisions. Layton recalled, “A message partially decrypted but with blanks in important places grammatically or subject-wise can render an 80% message somewhat less than 40% reliable in fact!” Moreover, “This fact is, again, something the reader of this sort of matter just can’t understand until he has to make a decision on fragmentary, incomplete intelligence.” Indeed the practice of providing interpretations based on incomplete messages for immediate tactical as opposed to strategic purposes proved dangerous and was later curtailed.11
Radio intelligence became an incredibly valuable asset for the hard-pressed Pacific Fleet in spring 1942. It negated Japan’s great strategic advantages of interior lines and the initiative by allowing the Allies to deploy their weaker forces to best advantage to surprise and blunt enemy offensives. There has been a tendency to regard radio intelligence as the sole factor in the U.S. success (as if the fighting were not important) and to concentrate on its successes and ignore (or cover up) the mistakes. However, comint was not an end in itself, but only a tool for determining enemy intentions. Its true value concerned what it actually furnished to the combat commanders ashore and at sea and what they in turn did with it.
As of 4 April Inoue confidently anticipated having most of the Kidō Butai carriers to support the MO Operation, his late May offensive against Port Moresby and Tulagi. That was wishful thinking on his part, but his delusions quickly evaporated in the wake of a contentious debate between the Naval General Staff and Yamamoto’s Combined Fleet over fundamental strategy for the second operational phase. The Naval General Staff strongly urged an anti-Australia strategy through severing the line of communication with the United States. The capture of Port Moresby and the Solomons would open the way that summer to New Caledonia, Fiji, and Samoa. As for the northern theater, the Naval General Staff hoped to seize positions in the western Aleutian Islands, not only to bolster the northern flank, but also to please the army by threatening the line of communication between the United States and the Soviet Union. For his own part Yamamoto, about to take a crack at the Eastern Fleet, proposed shifting the offensive all the way to the central Pacific to destroy his principal opponent, the U.S. Pacific Fleet. He keenly regretted not taking out the U.S. carriers along with the battleships at Pearl Harbor and now would finish the job once and for all in one massive blow in early June. The bait was to be Midway. Yamamoto believed its capture would draw the Pacific Fleet out for annihilation. Victory would deeply demoralize the Americans and open the way for the eventual invasion of the Hawaiian Islands. If the Pacific Fleet cravenly chose not to play its role in Yamamoto’s script by fighting (and losing), Japan would acquire a useful outpost.12
Beginning 2 April the proponents of these rival plans dueled in Tokyo. The Naval General Staff pressed its South Pacific strategy. If anything was to be done in the north, the Aleutians must come before Midway. Combined Fleet felt equally adamant about its Midway plan. Neither side gave an inch. On 5 April the Combined Fleet staff representative played his trump card—a telephone call to his chief on board his new flagship, the super battleship Yamato. Yamamoto expressed his wholehearted support of the Midway plan. His prestige carried the day. The Naval General Staff had little choice but to accept his Midway stratagem or relieve him of command. Yamamoto compromised by agreeing to conduct the Aleutians (AL) Operation simultaneously with the big assault on Midway (MI Operation). The AL Operation is usually described in Western sources as a diversion for the Midway attack, but that is completely wrong. In fact, the initial carrier strikes against Dutch Harbor and Midway were to go in at dawn of the same day. Also the very idea of such a “diversion” makes no sense given the relative strategic positions of the Aleutians, Midway, and Oahu. Yamamoto brashly counted on having enough strength for both offensive operations at the same time. In truth he seriously dispersed his forces, which meant, in the end, the Aleutians foray only diverted the Combined Fleet.13
The MI and AL Operations were to occur in early June after the Kidō Butai enjoyed much-needed upkeep in the homeland. Therefore Yamamoto advanced the Port Moresby Operation to early May. Inoue’s first inkling of the radical change came the day after he announced the MO Operation would take place in late May. On 5 April Combined Fleet promulgated a new task organization, effective 10 April, for the first stage of the second operational phase. For the MO Operation, Inoue’s South Seas Force would be loaned the big carrier Kaga, light carrier Shōhō, and the 5th Cruiser Division, but only until 10 May. These new orders were a great blow to Inoue. Not only did he not get all the carriers he thought he was promised in March, but he also must complete the MO Operation in time to return those borrowed units for Midway. He violently opposed the Midway gambit and made no secret of his distaste for the Combined Fleet brass. But now he had little precious time to complete detailed planning for the MO Operation.14
When Combined Fleet cut orders on 5 April assigning the Kaga to the South Seas Force, she became an addressee for certain communications concerning the MO Operation that passed between Yamamoto and Inoue. Within a few days messages intercepted by cryptanalysts at Pearl and Melbourne linked an important unit of the Combined Fleet, the Kaga, to the Fourth Fleet (South Seas Force) and something called the “RZP Campaign.” Intelligence speculated that RZP referred to Port Moresby. The new carrier “Ryūkaku” (wrongly thought another big Shōkaku-class carrier, but whose call sign was actually the Shōhō’s) was already known to be associated with the Fourth Fleet. That implied at least two flattops earmarked for a future southern Pacific offensive. Thus on 10 April McMorris speculated the Japanese might advance south from Rabaul possibly as early as 17–21 April, because Rabaul’s reinforced air force should be ready by then. On 11 April Leary likewise warned of an attack against eastern New Guinea by 21 April.15
Inoue looked with dismay at only the Kaga and Shōhō and wanted the 2nd Carrier Division (Sōryū and Hiryū) as well. Unwilling to commit the 2nd Carrier Division, which had to rest before fighting at Midway, Yamamoto substituted the 5th Carrier Division (Shōkaku and Zuikaku) for the Kaga. The Kidō Butai’s most modern carriers, they were the least experienced and would supposedly benefit from a warm-up in the Coral Sea prior to the main event at Midway. On 10 April Yamamoto revised the task organization for the first stage and two days later issued formal orders attaching the 5th Cruiser Division, the 5th Carrier Division, and two destroyer divisions to the South Seas Force, effective 18 April. For the time being U.S. cryptanalysts missed the fact that the Kaga was no longer part of the Moresby operation, but their British counterparts at Colombo quickly learned of two new carriers about to appear in the southwest Pacific. They recovered nearly in total a 13 April message to Inoue advising that the 5th Carrier Division, after splitting off from the Kidō Butai near Singapore, would stop on 18 April at Bako on Taiwan, then proceed to Truk around 28 April. The Admiralty passed the word to King (one of the first times this was done), who warned Nimitz and Leary on 15 April.16
Now it looked to King, Nimitz, and Leary that as many as four enemy carriers would be available by the end of April for an offensive in the southwest Pacific. That was a natural assumption given the general withdrawal of Japanese naval units from the Bay of Bengal. “We are planning opposition,” the Pacific Fleet War Plans Section noted on 16 April, although that was not Cincpac’s call. Nimitz worried whether Cominch would release the necessary forces, starting with Fitch’s TF-11, to give him a fighting chance. So did MacArthur, who on the seventeenth expressed his concern that the carrier task force ordinarily stationed in the Coral Sea had left for Tongatabu. “Consider it necessary that one task force be maintained that area at all times to check further enemy advance.” Nimitz quickly explained that TF-17 was being withdrawn due to the length of time it had been at sea and the trouble with its fighters. “Strongly agree desirability maintaining force in Coral Sea and will endeavor to do so,” he soothed. “Believe persistent courageous attacks by your aircraft have delayed enemy offensive and that Fletcher will return to area in time to oppose advance involving surface forces.” According to his biographer Potter, Nimitz was now “seriously regretting” the Tokyo raid. The fifty-dollar question remained whether Fletcher would have the necessary help. “We are trying to get a force together to oppose,” War Plans noted, “TF17 will be ready, TF11 and TF16 are otherwise committed.” Nimitz picked away at King regarding Fitch, who sailed on 15 April to meet the old battleships south of Hawaii. On the heels of the MacArthur message, Nimitz braced King privately: “It is my strong conviction that enemy advance should be opposed by force containing not less than two carriers. Again recommend that Fitch proceed Coral Sea where Fletcher will join him after upkeep.” Nimitz did not want Pye venturing beyond the Palmyra-Christmas line and desired the battleships to return to San Francisco.17
On the evening of 18 April as TF-17 neared Tongatabu, Forrest Biard, the Yorktown’s saturnine language officer, emerged from his green-curtained radio room shouting: “They bombed Tokyo, they bombed Tokyo!” He listened to Japanese domestic news broadcasts that he judged more reliable than American, for at this dismal stage of the war the enemy had less to conceal. What he heard cheered him beyond measure. Japanese radio angrily reported air raids against Tokyo, Yokohama, Kobe, and Nagoya. By dawn on the eighteenth Halsey brought the Enterprise and Hornet within 650 miles of Japan and intended to launch Doolittle’s B-25s that afternoon when the range decreased to four hundred miles. The Doolittle flyers would attack Japan that night and proceed on to China. Early that morning, however, TF-16 ran afoul of a line of picket boats, whose alarms Lt. Gilven M. Slonim’s radio intelligence team in the Enterprise soon intercepted. Therefore Halsey reluctantly dispatched the B-25s from beyond six hundred miles, later apologizing to Doolittle for having to “dump you off at that distance.” Expecting only short-ranged carrier planes, Combined Fleet judged any air attack had to be a day away. Yamamoto was astonished that afternoon when fast medium bombers roared over Tokyo and other cities. Physical damage proved slight, and all the B-25s crashed, except one that took refuge in the USSR.18
The shock to the Japanese psyche proved as immense as the satisfaction gained among the Allies. Given the growing crisis in the southwest Pacific, the War Plans Section at Pearl delivered a less sanguine private verdict to Nimitz. The Enterprise and Hornet were sorely missed. Even if King released TF-11 (which must happen quickly), “Cincpac will probably be unable to send enough forces to be sure of stopping the expected Jap offensive.” At the time Fletcher had only an inkling Halsey executed the raid. Once he learned the details he judged that although the exploit was great for morale, it tied up two carriers urgently needed in the Coral Sea. Yamamoto roused Combined Fleet to chase the U.S. carrier force, but Halsey had too great of a lead. When the Allied cryptanalysts analyzed the many messages that orchestrated the pursuit of Halsey, the raid yielded an unforseen bonus of excellent radio intelligence. The Doolittle raid had no effect on the choice of Midway as the next main objective or the rescheduling of the MO Operation against Port Moresby. Those decisions were already made. It did whet Yamamoto’s desire for a full reckoning with the Pacific Fleet.19
King waited a day before replying to Nimitz’s request for TF-11, perhaps to see if Halsey indeed got clean away. He was relieved to report to Nimitz, Leary, and MacArthur that the reference to 21 April for the start of the Japanese offensive resulted from an error in decryption. Three or 4 May appeared more likely, especially in light of the Admiralty decryption placing two carriers at Truk on 28 April. Port Moresby would be the objective of a seaborne assault and possibly also a land attack. Cominch’s next comment likely elicited profanities at Pearl, for King now proposed that “if supply vessels can be gotten there,” TF-17 should go to Nouméa for upkeep instead of remote Tongatabu. This marked an abrupt about-face from his vehement insistence on Tongatabu or Auckland, no matter how inconvenient. For MacArthur’s benefit he stressed that “in any case we can not repeat not accept commitment to maintain fleet forces continuously in Coral Sea or any other area but must employ them where situation requires.” No general would tell Cominch where to deploy his ships. TF-17 was too weak on its own, even with MacArthur’s help, to withstand the enemy, so King finally approved Nimitz’s request to deploy TF-11 southward. As yet he refused to countenance returning the battleships to the West Coast. Nimitz and MacArthur were to advise as to “maximum concentration of forces of all categories you consider possible to make against enemy New Guinea area first part of May.” That evening Nimitz quickly disabused King of the notion of Fletcher refurbishing at Nouméa. “Consider it impracticable to change base for upkeep and that departure Bleacher on 27 April for Coral Sea conforms to present requirements of the situation.” He immediately alerted Fitch to start south toward Fiji. The new orders found TF-11 heading northeast toward the TF-1 rendezvous after having flown the marine fighters to Palmyra. Three days later Nimitz issued the actual order for Fitch to meet TF-17 on 1 May (local time) in the eastern Coral Sea, where Fletcher would take command of the assembled force. Nimitz also informed Fletcher of his estimate of the situation and that “reinforcement for Taskfor 17 at later date under consideration.”20
In mid April Nimitz emerged as a leader grown dramatically in confidence and resolve. Earlier he fretted as King shifted the Pacific Fleet’s center of gravity southward and in the process took away most of his striking force. The Japanese firmly held the initiative and King, it seemed, most of the cards. Nimitz appeared at times hesitant and indecisive as he fumbled in reaction to events rather than seeking to control them. Speaking much later of that time, Adm. Arthur Davis, in 1942 a captain and Pacific Fleet staff aviation officer, frankly characterized his boss as “scared and cautious.” A foreign naval observer who met Nimitz in January uncharitably described him as “an old man, slow and perhaps slightly deaf.” King sensed weakness, for he was notorious for bullying subordinates he thought were not tough enough. By the third week of April, however, Nimitz found his sea legs as a theater commander. The Cincpoa directive significantly enhanced his power. Radio intelligence greatly improved. At the same time there was a major change in the personnel immediately around him. Pye, hitherto Nimitz’s closest advisor, already departed to become CTF-1, and McMorris left War Plans on 15 April. Their influence on Nimitz certainly was not baleful, but their exit cleared the air and made it easier for him to do what he must. Moreover, Milo Draemel’s days as chief of staff were numbered. Earnest and hardworking, he was overtired and stressed by the constant pressure and disagreed with Nimitz’s growing eagerness to confront the enemy. Capt. Lynde McCormick (USNA 1915), McMorris’s assistant, took over the War Plans Section. As bright in his way as McMorris but not fixated on the central Pacific, he was less domineering and under the circumstances easier for Nimitz to work with and through.21
Another key Cincpac personal relationship was with Commander Layton, the Pacific Fleet intelligence officer, who developed an excellent rapport with Nimitz. He described his boss’s demeanor as the “coolest, most self-collected [and] sunny at the same time.” In April Layton created a daily “score card” (the Cincpac Enemy Activities File) that displayed for Nimitz the location of enemy fleet units and their estimated intentions. Despite the tremendous trust Nimitz demonstrated in radio intelligence in general and in Layton in particular, he could not afford to be completely credulous and uncritical. He assigned a senior War Plans officer to offer his own analysis of the daily intelligence to balance that of Rochefort and Layton. McCormick handled that responsibility until 13 April, when he turned it over to Capt. James M. Steele. Layton deplored “Boob” Steele as especially obtuse and stubborn, but Nimitz considered him an essential brake against over-enthusiasm by Hypo. The physical arrangements in Cincpac headquarters at the Pearl Harbor submarine base also improved in April. Capt. Walter S. DeLany’s Operations Section ran the plot room, which featured strategic and tactical displays on large maps with friendly and enemy positions depicted for the whole Pacific. Four newly assigned naval reserve officers, who trained at the Naval War College, became the operations watch officers as part of an expanded system for recording ship and aircraft movements and contacts. A pneumatic tube delivered messages directly from communications so the latest information could be entered immediately. When the situation was at all tense, Nimitz and Draemel kept a close watch on the plot, where they could confer at once with McCormick, DeLany, and Layton.22
The rapidly changing strategic situation demanded that Nimitz himself make all the major decisions at fairly short notice. He reserved to the staff, most particularly McCormick’s War Plans Section, the task of properly framing and presenting his intentions. That was vital, because he was on the cusp of a stunning reversal of strategic policy. On 20 April Nimitz met informally with McCormick’s team to explain his thoughts regarding the threat in the southwest Pacific. He wanted to have, prior to his conference with King later that week in San Francisco, a concrete plan that reflected his ideas. Within two days McCormick prepared a detailed—and sober—estimate of the situation. Three May was the likely starting date of the New Guinea–New Britain–Solomons offensive. Ultimate enemy strength was not yet known, but it was believed that at least five carriers (Shōkaku, Zuikaku, “Ryūkaku,” Kasuga Maru, and Kaga with 306 aircraft) were involved, with indications that Nagumo’s flagship Akagi (sixty-three aircraft) might also participate. One fast battleship appeared committed, probably along with another, because the Japanese invariably operated their battleships in pairs. Five heavy cruisers with the usual supporting cast of light cruisers and destroyers were also thought en route to the area. Estimates remained vague regarding ground forces, but McCormick believed the Japanese had sufficient troops available to overrun Port Moresby. Nimitz and the planners recognized the enemy had his eye on objectives beyond Rabaul. “Will it only be for Moresby or Moresby and the Solomons at this time or will a direct advance to Nouméa or Suva be attempted?” Past Japanese practice of a step-by-step advance supported by land-based air indicated to McCormick that Port Moresby and the Solomons were the first objective. This by no means precluded carrier raids on New Caledonia and Fiji or Townsville and Horn Island in northern Australia, with very likely a widespread South Pacific offensive to follow. McCormick even warned against possible strikes against Efate, Tongatabu, and Samoa that could seriously disrupt efforts to reinforce those bases in May. He was not certain how the Japanese would employ their carriers, but probably not all would appear in the first wave.23
The obvious response was to commit the “full strength of the Pacific Fleet.” The 22 April situation report deemed that impractical for many reasons. Despite Cominch’s enthusiasm for the old battleships, Nimitz excluded TF-1. He could not support it given tenuous logistics or properly protect it with screening ships and aircraft, especially because those battleships were far too slow to stay with the carriers. Nimitz desired TF-1 to remain on the West Coast. Unlike King he had seen the battleships—huge holes ripped in their sides by aerial torpedoes—resting in the mud at Pearl Harbor. The Yorktown and Lexington were already committed to the South Pacific, but they alone could not handle five or six flattops. At least one carrier from TF-16 must go south, so why not both? “Nothing appears to be making for Hawaii yet. Other demands do not appear very strong, so we may find a force in the Southwest even larger than listed.” Cincpac could ultimately deploy four carriers (three hundred aircraft) for the great South Pacific battle. Expected back on 25 April, Halsey’s TF-16 could sail by the end of month and join Fletcher around 14 May (east longitude date). The only concern was whether the Hornet had a full complement of planes. The seven available fleet oilers could support both task forces in the South Pacific until about 1 June. Thereafter chartered tankers would have to be diverted from West Coast–Oahu runs to Fiji and Samoa. TF-16 would fight alongside TF-17 and then relieve the Yorktown and later the Lexington as well. Fletcher should start north around 15 May, because the Yorktown desperately required navy yard upkeep. Fitch’s Lexington force would need to follow about 1 June. The flying boats at Nouméa, serviced by the Tangier, should be increased from six to twelve. MacArthur’s Southwest Pacific Area would provide land-based air support, a cruiser task force, and a half-dozen submarines. In addition Pearl was sending five subs to patrol the waters around Truk.
Thus Nimitz resolved to hurl all four of his flattops into battle in the South Pacific, not purely for defense, but to seize the initiative. The most effective way was to crush the enemy’s strongest asset, his carriers. For months the Kidō Butai led the triumphal advance through the western Pacific to the Indian Ocean, while U.S. carriers only essayed pinprick raids on the periphery. To assault the South Pacific bases, the Japanese must expose a substantial part of their carrier fleet, hitherto effectively out of reach, out to where a resourceful defender could counterattack with carriers, land-based air, and subs for a great opportunity to smash them. Nimitz projected an attitude of quiet confidence, not desperation. The Japanese were not as formidable as they seemed. “Because of our superior personnel in resourcefulness and initiative, and the undoubted superiority of much of our equipment, we should be able to accept odds in battle if necessary.” The final decision regarding TF-16 had to wait until the Cominch-Cincpac meeting. On the twenty-second Nimitz sent King a list of potential forces available to counter the enemy’s South Pacific offensives. In addition to TF-17 and TF-11 (two carriers, five heavy cruisers, thirteen destroyers, and two fleet oilers), TF-16 with two more carriers, four cruisers, eight destroyers, and two fleet oilers could arrive there about 14 May. He again made the pitch for the battleships returning to San Francisco, “after remaining sufficiently long at sea to have effect on enemy dispositions.”24
On 23 April Nimitz flew to San Francisco to see King on the twenty-fifth. It was the first time they met since Nimitz left Washington. King arrived fresh from lengthy meetings with First Sea Lord Pound, who flew to Washington on 19 April to discuss fleet commitments in the North Atlantic, the Mediterranean, and the Indian Ocean. Significant Atlantic Fleet units were being deployed to European waters, while the carrier Wasp delivered British Spitfires to Malta. Pound questioned King regarding future operations in the Pacific that might ease the pressure on India and the crucial supply lines passing through the western Indian Ocean. He did not consider the Doolittle raid enough of a diversion. King’s response deeply disappointed Pound, who told his government that nothing King proposed for the Pacific would be likely to have much of an immediate effect on the critical situation in the Indian Ocean. That was true because King still only projected a buildup of bases in the South Pacific as a prelude to a push perhaps that autumn toward Rabaul. He needed Nimitz to start offering substantial ideas on how and where to commit the fleet to battle.25
The long and varied agenda demonstrated that Cominch and Cincpac had much to say to each other. Among the first items discussed was Fletcher’s recent Coral Sea cruise. According to the conference minutes, both men “expressed uneasiness,” but “decided to take no further action until more information is available.” (The same could be said for King’s true feelings toward Nimitz.) The two deliberated personnel matters, particularly flag officer assignments. Younger officers needed to qualify for carrier command by means of “makie-learn” cruises. Nimitz preferred not to deal personally with flag officer reassignments, but recommended they proceed through proper channels. He would come to regret that concession. Once these matters were addressed, Nimitz laid out his bold plan to concentrate the four carriers, all the fleet’s offensive assets, in the South Pacific by 13 May. Noncommittal as yet, King examined in detail the logistical support that radical redeployment would require. Still obsessed with the old battlewagons, he directed Nimitz to look into stationing Battleship Division (Batdiv) Three (Idaho, Mississippi, and New Mexico) in New Zealand.26
On 26 April King lectured Nimitz on the general Allied strategic situation and logistics. Dissecting the Cincpoa directive, he made it clear that once Ghormley was in place, the task forces in the South Pacific would “operate under his suzerainty.” Moreover, “when Ghormley drives to northwestward, it is to be expected that MacArthur will conform.”27 King carefully considered whether to authorize Halsey’s carriers to go south, a move that would expose the central Pacific. Consequently he asked whether Midway was safe from a “major attempt.” Nimitz replied that the island would need direct support from the Pacific Fleet to weather attacks by two or more carriers and promised to look into the matter of Midway’s defense. King and Nimitz again debated carrier organization. For “flexibility of assignment and deployment,” they settled on five single-carrier task forces, each under its own flag officer and ideally operating in pairs. That was yet more evidence that the U.S. Navy much preferred tactical dispersion for the carriers. King reminded Nimitz to see whether Auckland could support the old battleships and offered him the new battlewagons North Carolina and Washington when the Atlantic Fleet could spare them, probably in August.28
Nimitz left San Francisco on the afternoon of 27 April after a third session without knowing King’s final decision regarding his South Pacific battle plan. Upon arriving at Pearl the next morning he was enormously gratified by Cominch’s dispatch. “Think TF16 should proceed towards critical area as indicated with Hornet Air Group augmented as practicable in Hawaii or from Yorktown. Also concur in proposed return of TF17 and any other dispositions appropriate to keeping at least equivalent of TF16 in South Pacific Area.” King again directed “full consideration to sending one batdiv preferably Batdiv 3 towards same area with other BBs [battleships] returning to West Coast for time being.” Nimitz immediately requested Cominch approval to return all the battleships to the West Coast about 10 May and advised that happily the Hornet already had all her aircraft. Thus TF-16 would leave Pearl on 30 April. He breathed a sigh of relief when King concurred with his proposed retirement of all battleships. Cincpac got what he wanted. Now he could fight his carrier battle in the South Pacific. The meeting at San Francisco cleared the air. After faltering in the beginning, Nimitz was obviously on the right path. Reflecting both assurance and an aggressive nature, he presented a comprehensive plan that persuaded a skeptical King to take the enormous risk of finally committing his carrier task forces to battle.29
Nimitz conferred with a weary Halsey while TF-16 prepared for a quick return to sea. The far northwest Pacific had proved arduous as well as exhilarating. He outlined the now familiar, nevertheless chilling, estimates of enemy South Pacific objectives that included Port Moresby and the Solomons, as well as Ocean and Nauru islands. Carriers might also raid New Caledonia and Fiji. On the way south Halsey was to reconnoiter Howland and Baker islands and hit the Gilberts, “Whenever information and other conditions indicate that it may be profitably done.” Once in the Coral Sea he would command all the carriers briefly to number four before Fletcher departed with the Yorktown. Therefore Halsey “should be able to strike the enemy a heavy blow if suitable objectives can be found.” Later he should have the three carriers “long enough to complete another offensive operation.” Nimitz “strongly hoped that this powerful force can be put to good use” before Fitch, too, had to leave. “If present indications continue,” Nimitz stated he would “probably find it desirable” to redeploy the Yorktown and Lexington to the Coral Sea after they refitted at Pearl. In that event Halsey could again lead the four carriers. In the meantime he should consider sending one carrier at a time to replenish at Nouméa. Halsey sailed on 30 April with two carriers, three heavy cruisers, seven destroyers, and two fleet oilers. A heavy cruiser and a destroyer would follow on 2 May. Nimitz advised MacArthur, Leary, and Fletcher that TF-16 “should arrive your area about 12 May.”30
On 1 May Rochefort radioed “Hypo’s Evaluation of the Picture in the Pacific” to Opnav, Belconnen, and Com 16 on Corregidor. This message offers a very important summary of what he (and hence Nimitz and Layton) was thinking. Enshrined in Midway lore is the notion that Nimitz, when he was planning to fight in the Coral Sea, already knew from radio intelligence about an upcoming attack on Midway. Nothing could be further from the truth. On 1 May Rochefort explained that enemy fleet units in the Bay of Bengal had redeployed to the Pacific. “Their departure indicated a change of plan forced on Japan by us. Suggest movement of Pacflt [Pacific Fleet] TF1 as possible reason.” That politic flattery of Cominch showed that he knew of King’s partiality toward using the old battleships as a deterrent. As for “MO Campaign now underway,” Rochefort pegged southeast New Guinea and the Louisiades as the crucial area. The lineup comprised the 5th Carrier Division, 5th (heavy) and 18th (light) Cruiser Divisions, 6th Destroyer Squadron, 8th Gunboat Division, several aircraft tenders, transports, and possibly a submarine squadron. Available air strength included sixty-five bombers, sixteen flying boats, and an unknown number of fighters. “Crudiv 5 and C-in-C Fourth Fleet [is] in Rabaul region tonight.” (They were actually at or near Truk.) Rochefort did not think Australia would be involved despite a message that gave Townsville as a reference point. That soon changed. Rochefort also detailed powerful forces, including the 1st and 2nd Battleship Divisions, the 4th and 6th Cruiser Divisions, and carriers Kaga and Sōryū, that were “available for offensive-defensive operations.” Strong Japanese interest in Palmyra, Samoa, Canton, Howland, and Baker islands led him to speculate that “part or all of above units will cover MO Campaign with possible raids on Samoa and Suva areas.” That was the basis behind Nimitz’s strong commitment to fight in the South Pacific and again refutes subsequent hallowed assertions that Hypo already fingered Midway as the next likely objective. Rochefort noted the Kaga’s link to the Fourth Fleet and wrongly believed she was “scheduled for operations in New Britain area.” He judged the Aleutians to be the only other potential hot spot in the Pacific and a possible objective of these forces. “This considered unlikely at this time, but certainly is probable at a later date.”31
That last part worried King, who took to heart Rochefort’s warning of powerful Japanese forces that would soon be available for “offensive-defense operations.” On 2 May he admonished Nimitz and MacArthur not to get too wrapped up in the southwest Pacific. Acceptance of Nimitz’s strategy “must not be construed as eliminating the possibility that enemy may attack Hawaii-Midway line or launch attacks against our line of communications via Gilbert-Ellice-Samoa line.” In that regard the next few weeks would prove quite interesting for Cominch and Cincpac alike.32
Comint had provided and would continue to provide vital predictions of the South Pacific onslaught against which King and Nimitz courageously redeployed their forces. Now it was up to Fletcher to deal with the first blow and hopefully still be around to help Halsey smash the second.
Table 9.1 Estimated Japanese Carrier Strength According to an ONI Report
Office of Naval Intelligence (ONI) Intelligence Report Serial 44-42 (22 April 1942), in RG-313, Commander, Fleet Air, West Coast (Comfairwest), Box 1003.
Note: “VF” designates fighting planes, “VSB” designates scout bombers, “VTB” designates torpedo bombers, and “CV” designates aircraft carriers.
a Smaller figures indicate spare or reserve aircraft (which usually were not present).
b Estimated.
Table 9.2 Actual Japanese Carrier Strength 1 May 1942
Notes: “VF” designates fighting planes, “VSB” designates scout bombers, “VTB” designates torpedo bomber, and “CV” designates aircraft carriers.
a Smaller figures indicate spare or reserve aircraft (which usually were not present).