Codebreakers Victory (36 page)

Being surprised had become almost standard operating procedure for the clueless Japanese military. So it was with Nimitz's August 7 landing on Guadalcanal. The small Japanese contingent on the island, mostly laborers, offered little opposition to the invaders. In just thirty-six hours the Marines had captured the airstrip, which they named Henderson Field in honor of a flight commander who had died leading an attack at Midway. Tulagi, the island adjacent to Guadalcanal, was seized after suicidal resistance by the Japanese troops occupying it.

American commanders, having to proceed without guidance from their codebreakers, were also vulnerable to surprise. That came on the night of August 8, when a Japanese fleet slipped past Savo Island off Guadalcanal and attacked the warships protecting the landing. Four heavy cruisers—three American and one Australian—were lost to the Japanese guns and highly superior Long Lance torpedoes. The ships supplying the Marines ashore backed off after delivering only half their supplies and food. When the engineering equipment needed for work on the airfield was withdrawn, the Marines used abandoned Japanese machines to do the job.

In a tragic twist, Allied intercept operators had delivered into cryptanalysts' hands the message detailing the Imperial Navy's planned course of action off Guadalcanal, but the codebreakers were unable to solve it until two weeks after the battle had been fought.

The Battle of Savo Island was the first of seven naval engagements that battered both antagonists over the next six months. Each side had twenty-five ships sunk—so many that the waters there came to be known as "Iron-bottom Sound." As noted by Guadalcanal veteran Phil Jacobsen on his Web history of the Pacific war, the total of Allied sailors who lost their lives at sea was more than three times that of Marines and GIs killed on land.

Meanwhile, the struggle on Guadalcanal surged back and forth in the island's fetid jungles and malarial swamps. The Japanese, recognizing that the loss of the island would punch a dangerous hole in their defense perimeter, were as determined to retain the island as the Americans were to drive them out.

Japanese movements were being tracked by an unseen foe. Even when Hypo and Melbourne were blacked out, the coast watchers filled in. On September 30, 1942, for example, they warned of a cruiser force heading toward Guadalcanal to bombard the Marines there and put Henderson Field out of commission. So warned, an American fleet met them in the Battle of Cape Esperance. It was a confused struggle, a strategic draw in terms of damage done, but the Japanese ships turned back.

The time of drought for the main Allied cryptographic centers finally ended. In late August they began breaking into the new JN-25 code and by late September were reading it expeditiously enough to supply useful tactical information. When on October 1 the Japanese activated a new substitution table meant to throw off cryptanalysts, the Allies broke it in two days.

With Henderson Field planes controlling the air by day and Allied intelligence units guiding the destruction of large-scale attempts to reinforce and supply Imperial troops on Guadalcanal, the Japanese were reduced to night runs, which became known as the Tokyo Express. Even a number of these runs, however, were anticipated and the transports sunk.

Frustrated, the Japanese high command decided in November to mount one more strong effort to dislodge the Marines. The Tokyo Express landed so many reinforcements that for the first time, the Japanese outnumbered the Americans on the island. Admiral Yamamoto, revered despite the Midway disaster, commanded a task force that sought to add to those gains by bombarding Henderson Field while eleven transports ferried in additional infantrymen and tons of supplies.

The codebreakers told Bull Halsey, now in overall charge of the American and Australian fleet, what to expect. There followed three days of vicious righting, the two naval battles of Guadalcanal. Poorly commanded American ships suffered severe losses, but the Japanese fared even worse. Most important, eight of the Japanese transports were sunk and thousands of the soldiers drowned.

By the first week of December, the Tokyo Express was limited to runs by submarines bringing in wholly inadequate supplies to the sick and starving troops. Allied decrypts foretold another desperation measure: a run by fast destroyers bearing 1,200 drums of supplies. Halsey saw to it that the destroyers were shot up and turned back. Only 220 of the drums reached land.

The time for the denouement on Guadalcanal had arrived. In late January 1943, decrypts alerted the Allies to a Japanese plan for a new series of warship runs to the island. What the messages failed to disclose was that the ships were not there to bring in reinforcements. Their purpose was evacuation. The Tokyo Express rescued thirteen thousand emaciated soldiers, all that were left of the thirty-six thousand who had come there to fight. By contrast, American losses were just over a thousand dead.

Nimitz sent out a message that read, "Once again radio intelligence has enabled the fighting forces of the Pacific and the Southwest Pacific to know where and when to hit the enemy." He added, "My only regret is that our appreciation, which is unlimited, can be extended only to those who read this system."

Bull Halsey liked to think of the islands of the Pacific as a ladder, with each newly won island a rung in the climb toward Tokyo. Guadalcanal, now finally and irrevocably in Allied hands, was the first rung of the ladder to be ascended.

 

 

Hitting the Japanese Where They Weren't

 

In the division of Pacific war responsibilities dictated by the Joint Chiefs, Nimitz was required to provide MacArthur with naval support. In another of his smart decisions, Nimitz sent Halsey to work with The General. The two of them hit it off swimmingly, forming an ardent mutual admiration duo. In his MacArthur biography,
American Caesar,
William Manchester has told how MacArthur, after his first meeting with Halsey, clapped the admiral on the back and said, "If you come with me, I'll make you a greater man than Nelson ever dreamed of being."

Together they put into practice the strategy of finding out from intelligence where the Japanese were most expecting an attack and then striking their weaker spots somewhere else. For example, Halsey found out that the Japanese, after losing Guadalcanal, anticipated that the next target in the Solomons would be the island of Kolombangara, and they armed the island with ten thousand troops. Instead, Halsey bounded past them and seized Vella Lavella, garrisoned by fewer than a thousand. Outflanked, the Japanese had to evacuate Kolombangara, giving it up with scarcely a shot being fired. Similarly, on the large island of Bougainville, Halsey leapfrogged past the most strongly fortified base, at Buin, and sent his troops ashore at Empress Augusta Bay, farther along the coast. So he and Nimitz began climbing the island ladder.

MacArthur planned similar tactics on New Guinea. His first try, however, did not work out as he had hoped. When the Japanese had been stopped short of Port Moresby and their disease-ridden remaining troops were ordered to withdraw back over the Owen Stanleys, he directed that a pincer attack be made at Buna, on New Guinea's northern coast. His idea was to have a newly arrived American infantry division press from the land while an amphibious force came in from the sea. The General expected a quick victory over a weak garrison. The importance he attached to the Buna offensive is indicated by his final words to his field commander, General Robert L. Eichelberger: "Bob, take Buna or don't come back alive."

His twin attacks did surprise the Japanese, but then MacArthur encountered his own surprise. Instead of facing a few jungle-weakened, battle-weary survivors, his troops faced a large cadre of fresh reinforcements. The battle for Buna turned into a protracted, costly campaign.

Buna taught MacArthur several lessons. One was that he could not afford never going to the battle sites himself. By staying back at his spacious, elegant quarters at Port Moresby and letting his field commanders direct the fighting at Buna, he strengthened his GIs' estimation, and for many their detestation, of him as "Dugout Doug." Second, he learned not to allow his field officers to send their troops in direct frontal assaults if any other course was possible. On Buna these tactics cost almost twice as many men as were lost on Guadalcanal. And he might well have learned not to deepen the common soldiers' antipathy by issuing more of his grandiloquent communiqués, one of which at Buna claimed, in the face of what every GI knew to be false, that "probably no campaign in history against a thoroughly prepared and trained army produced such complete and decisive results with so little an expenditure of life and resources." This last lesson, though, was probably more than his imperial character could absorb.

Although Buna was a low point for him, the ultimate defeat of the Japanese there did force them finally to abandon any lingering hope of taking Port Moresby. It gave MacArthur a foothold to begin his daring moves up New Guinea's northern coast. And yes, Eichelberger did come back alive.

After Buna, The General corrected his image by becoming almost too visible to his combat troops. When his paratroopers were making their first landing on the New Guinea coast, he insisted on going along in the lead plane. When his troops made beach landings, he arrived while the fighting was still intense, striding forward helmetless, in his pushed-up gold-braided cap and noncamouflaged khakis, smoking his corncob pipe, and persisted in walking so near the front lines that he could poke with his toe at the still-warm bodies of snipers shot out of the trees. When others in his entourage dived for cover, he remained upright, presenting a target that, miraculously, never got hit.

In March 1943, Allied codebreakers set up another victory. A decrypt warned that the Japanese, determined not to give up another inch of the New Guinea coast, were dispatching to their base at Lae an infantry division of seven thousand troops, transferred from Korea and north China. The soldiers were to be conveyed from Rabaul in eight transports, escorted by eight destroyers.

Major General George C. Kenney, MacArthur's air chief, had already been working closely with the codebreakers in planning his air strikes. He read their decodes about the convoy as a fine opportunity to test out new antiship tactics he'd instituted. Bombs dropped from a great height, he had decided, rarely hit their targets. His alternative was to train his medium-range bomber crews to swoop in at a low level and send their fragmentation bombs skipping over the water like flat stones thrown from the beach. The bombs were timed to detonate only after they had penetrated the ships' hulls.

His skip-bombing techniques won the day in the Battle of the Bismarck Sea. Told by the cryptanalysts where to look, Kenney's recon planes spotted the convoy. Its ships were first intercepted by Flying Fortresses employing their precision bombing from on high. They sank only one ship. The next day, when the Japanese Zeros were high up in anticipation of another Fortress raid, Kenney's skip bombers sneaked in just above the wave tops—a neat turnaround on the tactics that had won at Midway. All eight of the transports, as well as four of the destroyers, were sunk, with the loss of thousands of Japanese troops. The battle put an end to Japanese attempts to move anything larger than a small barge by daylight when they were within range of Allied aircraft.

In the months that followed, MacArthur made slow, slogging progress up New Guinea's northern coast. By late January 1944, he had still gone only about a third of the way and faced strengthened Japanese defenses along the island's western two-thirds. However, another important cryptologic change had taken place. Previously MacArthur had been largely dependent on decrypts of Japanese naval codes; the army codes resisted penetration. But as the Allied troops pushed back the Japanese in the battles at a place called Sio, an engineer with a mine detector discovered a bonanza. The retreating infantry had buried a steel trunk that contained the division's entire cipher library. Within days Central Bureau was decoding army messages by the thousands.

The army and navy decrypts combined to tell MacArthur that the Japanese were expecting his next amphibious attack to be launched against Wewak and Hansa Bay, not far from his previous advance. They were so sure of what he would do that they had begun reinforcing their defenders at these sites, including shifting troops from their base much farther along, at Hollandia (now called Jayapura). On the strength of this information, The General decided not to take the small, expected step. He would make the big leap to Hollandia.

Most commanders regard military strategy from within the confines of their own particular service. Army officers, for example, are apt to regard water as a hostile environment. Not MacArthur. He, with Halsey in charge of his naval wing and Kenney the air, became adept at what the admiring Churchill called "triphibious" operations. According to Manchester's biography, during the Pacific war MacArthur made eighty-seven end-around thrusts from the water, and all of them were successful.

None was more so than his triphibious operations at Hollandia. Nimitz contributed by supplying carrier-based air support, but, concerned about exposing his carriers to Japanese bombers, he limited their participation to just three days. MacArthur responded by planning an additional landing at Aitape, 125 miles southeast of Hollandia. Capture of the Japanese airfield there would assure him of continuing air cover. His staff also worked out an elaborate series of deceptions. Kenney's planes played to Japanese preconceptions by bombing and strafing Hansa Bay defenses and by conducting highly conspicuous reconnaissance flights. Torpedo boats made themselves obvious in the area. Submarines left empty rafts ashore to suggest that patrols had been there to investigate landing sites. And when the Allied flotilla sailed toward Hollandia, the ships made feints toward the Wewak and Hansa Bay strongpoints, then at night swerved toward their real target.

MacArthur's quantum leap went off with few hitches. The landings at both Aitape and Hollandia were unopposed. Troops of the small Japanese garrisons faded into the jungle, most of them dying of starvation or succumbing to disease while trying to reach the nearest friendly base. The airfields were captured, and Nimitz's carriers retired without loss. A strong Allied force held the ground separating Japanese strength to the west from that to the east.