Codebreakers Victory (47 page)

In his rage at what he saw as a misplaced piece of irony, Halsey later admitted, "I snatched off my cap, threw it on the deck and shouted something that I am ashamed to remember."

On land, meanwhile, the Leyte landings quickly developed into a protracted, vicious struggle. The GIs had to battle monsoon rains and knee-deep mud in addition to reinforced hordes of Japanese infantrymen. As Allied decrypts revealed, the Japanese high command had resolved to make Leyte the climactic battle of the Philippines, possibly the turning point in the Pacific war. They poured in reserves of manpower and resources prodigally, drawing troops from as far away as Manchuria and planes from homeland defenses.

But for Allied decodes, the fighting would have gone worse for the GIs. Allied codebreakers supplied precise information about the routes of reinforcement convoys, and U.S. planes and submarines sank nearly three hundred marus and transports during the battle. One reinforcement flotilla was so thoroughly mauled that the only soldiers to reach the island were the ones who swam in from their sinking transports. Another convoy, bearing troops from Manchuria, was smashed by wolf packs of U.S. subs even before it could leave the China Sea.

Although MacArthur drove his commanders impatiently, he maneuvered to avoid costly frontal attacks. He kept the defenders off balance with strikes where they least expected them and with another triphibious end run that cut the enemy forces in two. The ground battles on Leyte destroyed more than five Japanese divisions.

The General would have fought against admitting it, but Leyte was, as Edward Drea has documented, a codebreakers' victory, one in which signals intelligence had "a starring role." As Drea summed up, "The Japanese high command, operating on woefully bad intelligence, gambled all at Leyte and lost. The American high command, acting on very good intelligence, took a well-calculated risk and won." The island was finally secured at Christmastime in 1944.

Aided by Filipino guerrillas, the Americans had already invaded Mindoro Island. MacArthur needed it as a stepping-stone toward his main objective, the large island of, Luzon and its capital city of Manila. The assault on Luzon began January 9, 1945. This was MacArthur's old stomping ground. Everywhere he saw symbols that stirred his vanity and fed his craving for speedy successes. He drove his field commander, the patient and dependable Walter Krueger, unmercifully, setting the date for the liberation of Manila on January 26 to coincide with his own birthday. He also began to plan a victory parade down the city's boulevards. When his subordinate generals became convinced that the numbers of Japanese defenders on the island were much larger than MacArthur's sycophantic intelligence chief had estimated, he rejected their claims—which in the end turned out to be correct.

In a crude effort to speed up Krueger's timetable, MacArthur dangled the reward of a promotion and a fourth star if his field general would move more quickly to take Manila. He was impervious to Krueger's protest that to extend his lines so recklessly would open him to Japanese flank attacks. The General was also sure that the Japanese would abandon the city after -token resistance. His final step to goad Krueger was to establish his own headquarters twenty-five miles nearer the front lines than Krueger's command post.

Krueger refused to launch his attack on Manila until he was reasonably ready. As he expected, the city was fanatically defended by the Japanese troops there. It could be taken only by furious, costly street fighting, building-by-building combat. The battle went on for three bloody weeks. Reluctantly, MacArthur authorized heavy artillery support of the infantry but refused the aerial bombardments asked for. The struggle for Corregidor, that other symbol held dear by MacArthur, claimed an additional thousand-plus U.S. casualties.

The General was not granted his birthday present. The Japanese in Manila held out until February 25. Outside the city, the Japanese troops retreated into the Luzon hills and were still fighting as guerrillas when the war ended.

In the midst of the Philippines struggle came an ominous development for the Allies. The Japanese high command had thought of a new weapon. On October 21, Vice Admiral Takijiro Ohnishi traveled to Mabalacat, one of the main airfields on Luzon, and met with pilots of the Twenty-first Air Group. He proposed that the fliers arm their Zeros with 550-pound bombs and crash-dive onto Allied warships. A total of twenty-three petty officer pilots immediately volunteered. While improvised suicidal flights had been made against the Allies at Saipan, the meeting on Luzon was the first systematic organizing of sacrificial squadrons. It was the full-bore beginning of
kamikaze,
the "Divine Wind," a reference to a time in the thirteenth century when violent storms had destroyed the Mongol fleets bent on invading Japan. The Divine Wind's first victory came on the last day of the Leyte Gulf battles. One of the two escort carriers opposing Kurita's fleet was sunk by a kamikaze.

The decision to ask young pilots to immolate themselves to save the empire was a symbol of the desperate straits to which Japan's leaders had come. By then the Nimitz-MacArthur pincer strategy was all but fulfilled. MacArthur's conquest of the Philippines deprived the Japanese war machine of the Southeast Asian oil it needed to keep on operating. Nimitz's island-hopping had drawn the ring around the homeland tight enough that American bombers were routinely devastating Japanese cities. Not knowing of the deus ex machina relief to be delivered by the atomic bombs, the Allied leaders began planning their final steps toward the defeat of Japan through the waging of conventional warfare.

 

 

 

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Europe: High-grade Decrypts Abet Allied Victory

 

 

For those GIs who lost friends in the Battle of the Bulge, it is difficult to look past that terrible bloodletting of American soldiers and see it the way military experts regard it: as ultimately a boon to the Allied cause. In the cold statistics of attrition the Germans lost heavily. The slaughter of their forces in the Ardennes, joined with the unrelenting drain of German strength by the Soviets, left the armies of the Reich unable to put up more than crumbling resistance, temporary holding actions and doomed counterattacks. GI sacrifices in the Bulge sped the Allied war machine toward triumph.

As the war in Europe entered its final stages, Allied commanders benefited from what Hinsley has described as "a large volume" of "high-grade decrypts." Merely to list all the main Enigma and Fish keys Bletchley Park was breaking took up a long paragraph in his intelligence history.

Information from these secret sources pointed up the inadequacies of German resources to meet the demands of the three frontiers in which the Nazi armies were engaged. In the west they tried to make the Rhine an impenetrable barrier. On the Russian front their defensive East Wall extended for two thousand miles from the Baltic in the north to the Black Sea in the south. And in Italy they sought to hold at bay the Allied armies under Alexander and Clark.

The decrypts also chronicled the frenetic shifts that Hitler and his generals ordered in their attempts to prevent a breakthrough. Now troops rushed eastward to check a Russian advance, now south to shore up Italy's Gustav Line, now west to try to fend off an Allied encirclement in the Ruhr. The German army no longer had reserves; all the fighting manpower was thrust into the front lines.

Germany's plight contrasted with the gathering might of the Allies. Both in manpower and materiel the Allied advantage was mounting to overwhelming proportions. Victory in the Battle of the Atlantic was allowing the unhampered flow of U.S. troops and supplies into Europe and enabling the Americans to fight their kind of war, which was to hurl vast barrages of steel against the enemy in order to limit the hazarding of men.

While Soviet losses were forcing the call-up of men outside the normal ages for military service, the Russians were still able to build their offensive capabilities to awesome levels. They were equipping their troops as never before: to the productive cornucopia from the factories they had moved behind the Urals was added the great influx of lend-lease supplies from the U.S. The Red Army was made mobile by Detroit-built trucks; the soldiers walked in thirteen million pairs of frostbite-defying felt boots manufactured by Americans to Soviet specifications; supplies were hauled by two thousand American-made locomotives and eleven thousand freight cars.

Hitler deepened the German troubles by further refusals to admit when his armies were overextended and facing insuperable odds. Still dreaming of tapping into southeast Russian oil, he issued stand-fast orders to his generals in the Crimea only to have more legions of German troops surrounded, captured and doomed to the rigors of Soviet prison camps.

To all these rising barometers for the Allies was added an unexpected bit of luck. In the West the Allies faced the necessity of crossing the Rhine, whose eastern banks were defended by troops fanatically determined to protect the homeland. On the morning of March 7, 1945, a Ninth Division recon pilot was aloft in a Piper Cub along the Rhine when he saw an incredible sight: the railroad bridge at the town of Remagen stretched across the river still intact, undestroyed by the Nazis. He radioed the news back to his general, William Hoge, who immediately ordered the nearest unit of the Ninth Armored Division to take the bridge before a German demolition team could bring it down. GIs under twenty-two-year-old Lieutenant Karl Timmerman found the bridge, dashed across it even as some charges were detonated and routed the Germans on the far side. This first American contingent was soon followed by four divisions of Omar Bradley's First Army, establishing a bridgehead several miles deep. The bridge was damaged and collapsed in a few days, but by then army engineers had six pontoon bridges spanning the river. As historian Martin Gilbert has pointed out, this was the first time an enemy invader had crossed the Rhine into Germany since Napoléon's crossing in 1805.

 

 

Sigint's Edge in the Air War

 

As the war in Europe wound down, Allied dominance owed much to the growing superiority of Allied air power. The Luftwaffe, having expended much of what was left of its strength in support of the Ardennes offensive, was all but wiped from the skies. Allied fighters and bombers roamed almost at will over a prostrate enemy. The planes of Britain's Bomber Command and the U.S. Air Force put the finishing touches on their devastation of the German economy.

This ascendancy came only after a long and perilous journey. And only when Allied intelligence combined with British and American science to win the struggle against German technological advances, the battle of measures versus countermeasures. German scientists proved to be a formidable source of lethal innovations that the Allies had to neutralize in order to keep their bomber losses and aircrew casualty rates from becoming "insupportable." But because of Enigma and Fish decrypts, Magic disclosures of what Japanese military attaches were learning and reports from secret agents and resistance fighters, the work of German scientists was no more secret than the plans of the military.

After British scientists and technicians had, early on, won "the battle of the beams" and had helped to foil Hitler's plans for invasion, their attention turned to advancing the technology of Britain's only offensive weapon: the planes of Bomber Command. Their goal was twofold: to reduce bomber losses by mastering German air defense systems; and to strengthen the accuracy, effectiveness and self-protection of British bombers.

Dr. R.V. Jones, Churchill's young science adviser, developed a close relationship with Bletchley Park and depended on BP decodes to keep him abreast of German technical developments. In his memoir he told how he and others of Britain's scientific team worked to understand the radar-based defenses the Germans were putting in place.

The scheme was ingenious. Along the northern coast of Europe the Germans installed a belt of radar detectors that gave early warning of the nighttime approach of streams of British bombers. This radar front line was tied in with an inland belt of more powerful units that were used for three purposes: to turn on a barrage of searchlights that picked the bombers out of the night sky, to alert the crews of antiaircraft gun batteries along the bombers' path, and to guide hordes of night fighters in intercepting the incoming raiders.

Percentages of bombers lost on each of the raids gave a measure of British technology's successes in thwarting the German systems. A "reasonable" loss was in the three-to-four-percent range, meaning that perhaps only a dozen bombers failed to return and fewer than one hundred men died that night. "Unacceptable" losses came when percentages soared above ten percent, as they did on the night of March 30, 1943. Then 96 of the 795 planes sent against Nuremberg, or more than twelve percent, went down. During 1943, the odds of a bomber crewman's surviving a tour of twenty operations were roughly one in six.

Against this grim backdrop, Britain's technical teams devised new ways to cut bomber losses. When one method of jamming enemy radar was countered, they introduced another, and then another. They put into use long strips of aluminum foil, called "window" by the British and "chaff" by the Americans, which on being dropped by diversionary planes caused German radar to see dense flights of bombers where there were none. Bomber Command's Air Marshal Arthur "Bomber" Harris has described the success of this development in his memoir,
Bomber Offensive:

 

The use of window had an immediate effect. On the first night of the attack the night of July 24th-25th, the radar controlled searchlights waved aimlessly in all directions, the gunfire was inaccurate, and in England the stations which intercepted the enemy's wireless traffic were immediately aware of hopeless confusion in the German ground control stations. In fact, the ground controllers gave the whole situation up, their instruments behaved as though the sky was filled with thousands of hostile aircraft, and they could do nothing to help them. A ground controller was overheard saying, "I cannot follow any of the hostiles—they are very cunning."