Codebreakers Victory (51 page)

Then came the crunch. Lieutenant General Mitsuru Ushijima, knowing he lacked the strength to defend the entire island, had concentrated his defenders on the craggy terrain of the southern sector. From their elaborate subsurface quarters, the Japanese soldiers trundled out huge mortars, uncovered powerful antitank guns and emerged for sudden counterattacks. They made the Marines and GIs pay dearly for every advance and stretched the campaign out for weeks, delaying plans for the invasion of the mainland.

Japanese resistance forced much of the protecting Allied fleet to remain in place, making it vulnerable to the suicide weapons. The Americans had precluded one use of sacrificial offense when, in taking the outlying islands, they had found and destroyed some two hundred and fifty explosives-laden plywood boats cached there to smash their loads against Allied ships. Still the Allies had to defend against the
ohkas
and kamikazes. The
ohkas
were ferried in by regular planes and, over their targets, released to dive to the destruction of their pilots and, so it was hoped, the warships below. As for the kamikazes, an appeal went over all Japan to assemble nonmilitary and obsolete aircraft to provide wings for self-sacrificing pilots.

On April 6, Japanese commanders sent aloft the first of ten
kikusui
raids. Regular pilots led the waves of kamikazes off fields on Taiwan and the homeland island of Kyushu and guided them to the Allied ships.

To counter these attacks, American intelligence units figured out when the mass kamikaze flights were launched and how long they would take to reach the Allied fleet. Marine Colonel Bankston Holcomb would then relay the information to Admiral Spruance. "He always listened," Holcomb later recalled, admiring how coolly Spruance issued his orders for meeting the incoming suicide planes. Once forewarned, navy gunners shot down an estimated sixty to ninety percent of the kamikazes and
ohkas
short of their targets.

Even so, the carnage was great." A total of 34 warships were sunk and 368 damaged, including 8 carriers, 4 escort carriers, 10 battleships, 5 cruisers and, because of their exposure in forward picket lines, 63 destroyers. Casualties among shipboard crews were the heaviest in the war.

British ships in the fleet fared better because of their armor-plated decks. None of their ships were sunk, although all four of their carriers as well as other vessels were damaged.

Meanwhile, on April 7 the suicide sortie of Japanese surface ships formed around the
Yamato
and arrived to do battle against Spruance's fleet. It goes almost without saying that Allied codebreakers knew the makeup of the fleet and the exact route and schedule of its approach to Okinawa. Sightings by a submarine and a B-29 confirmed the decrypts. Admiral Marc Mitscher, in charge of the Allied fleet's Task Force 58, had his riposte all worked out. One of his groups of strike aircraft was to concentrate on the
Yamato,
a second on the
Yahagi,
and after sinking these prime targets, all units would go after the eight destroyers. The Americans launched 386 aircraft against the suicide force, including 98 torpedo bombers.

It was no contest. Torpedo after torpedo slashed into the
Yamato,
causing her to roll over and go down, taking the fleet's admiral with her. The U.S. planes quickly dispatched the
Yahagi
and sank four of the destroyers. The other four limped back to Japan, three of them badly damaged. The Japanese navy had virtually ceased to exist.

The land battle of Okinawa continued until the beginning of July. Seeing their resistance crumble, Ushijima and his fellow general Isamu Cho killed themselves on June 22, leaving only ten days of American mopping-up operations to follow. This final battle of the Pacific war was also the bloodiest. Allied losses included over 12,000 army and navy men killed. More than 100,000 Japanese troops died. Because they callously used natives of the island as little more than cannon fodder to buy time for the buildup of defenses, an estimated 150,000 civilians were killed or joined in mass suicides.

 

 

Japan: The Greatest Battle Never Fought

 

In the early months of 1945 there seemed to be no alternative to preparing for the staged invasions of Japan. The Joint Chiefs of Staff settled on a plan for two major landings. The first, code-named Olympic, would invade the southern island of Kyushu on November 1. If Japan had still not surrendered by March 16, 1946, the follow-up would come. Code-named Coronet, it would target the main island of Honshu, whose broad Kanto Plain led to Tokyo. Douglas MacArthur was designated as commander in chief of the United States Army forces in the Pacific, including its air force units. Admiral Nimitz was designated the commander of all U.S. Navy units, while General Carl Spaatz was placed in charge of the Strategic Air Force.

An important question troubling Allied leaders, especially Harry Truman after he became president, was the number of Allied casualties likely to result from these invasions. During the final week of July, at the Big Three conference in Potsdam, Germany, Marshall gave his answer, based on estimates received from his subordinate commanders. Truman later wrote that Marshall told him that the invasions would cost "at a minimum one-quarter of a million casualties and might cost as much as a million." Even the lesser total would outnumber by far all losses in the Pacific campaign, including those at Iwo Jima and Okinawa, and would exceed Western Allied casualties in Europe from D-Day through the Battle of the Bulge.

Certainly the million figure seized the attention of Winston Churchill. He wrote, "To quell the Japanese resistance man by man and conquer the country yard by yard might well require the loss of a million American lives and half that number of British—or more if we could get them there; for we were resolved to share the agony."

MacArthur's judgment concerning the numbers was conditioned by his obsession with commanding the greatest amphibious invasion in history, one that would surpass Eisenhower's forces on D-Day by a wide margin. Since the question of unacceptable casualties might jeopardize this glory-seeking prospect, he seized every opportunity to play down both the estimate of Japanese strengths on the islands and the expectations of Allied losses. He let it be known that he did not anticipate a "high rate of loss" in the attacks on Japan and assured military planners, "The invasion of the Tokyo plain should be relatively inexpensive." He was opposed to "the slightest thought of changing the Olympic operation."

To take this stand, he had to fly in the face of his own codebreakers. As decrypts from those times have been declassified, they have accentuated the horrors that lay in wait for Allied invaders. The Japanese high command had come to the same conclusion reached by Allied leaders: that on Kyushu only three beaches were suitable for large-scale landings. Japanese planners made those beaches the most formidable death traps their fervid imaginations could devise.

Broken message after broken message detailed the enormous buildup of troops on the islands. To the two general armies, numbering two and a half million men, the Japanese added reinforcements from the Asian mainland—four divisions from Manchuria, others from Korea and north China. Additional troops came from the northern Kuril Islands and Hokkaido. Levies of remaining manpower called for raising new divisions totaling more than a half million men. In addition, there was the National Volunteer Corps—twenty-five million untrained children, old men, and women serving as a labor force but ready to convert to warriors armed with sharpened bamboo spears, pitchforks, rusty bayonets and even dynamite charges strapped to their bodies.

If the underground fortresses built by the Japanese on Pacific islands had presented deadly barriers to American GIs, these were nothing compared with the networks of subterranean tunnels, corridors and firing points constructed for defense of the homeland. Heavy guns mounted on rails could roll out from behind steel doors, fire their shots and retreat behind the closing doors before an answering shot could be made. Decrypts warned of the construction of underground hangars and concealed bases for aircraft. Acres of mines were sown in harbors and coastal areas. The National Volunteer Corps labored throughout the torrid summer to build bunkers, field fortifications and connecting tunnels along the shoreline.

Most of all, the high command relied on its newest weapon—the willingness of the young to die in suicide missions. As revealed by a steady stream of decrypts, plans called for a massive employment of this horrible strategy. Thousands of planes, largely obsolete, were rounded up to serve in kamikaze operations. A Japanese aircraft firm began designing a craft specifically for carrying a one-thousand-pound bomb on suicide missions. Hundreds of
kaitens
and
ohkas
awaited their sacrificial moment. At naval bases, midget submarines were stashed in sardinelike rows, most of them scheduled to be used as suicide craft.
Fukuryu
frogmen waited to turn themselves into human mines. Along the coasts riflemen dug themselves into fortified pits, expecting to die in the preinvasion bombardments but hoping to survive long enough to take a few Americans with them. Perhaps saddest of all were the new aircraft specially built with reusable landing gears: since the planes were destined to go only one way, why waste scarce rubber when the planes on takeoff could drop their wheels?

Despite the overwhelming proofs of the grim ordeals faced by Allied invaders, MacArthur continued to assert that the invasions would not involve serious losses. As Drea has pointed out, MacArthur consistently dismissed codebreakers' evidence "that failed to accord with his preconceived strategic vision."

Encouraged by the colossal defensive preparations being carried out by their people, Japanese planners clung to an unrealistic but persuasive goal: that their trained military forces and their multitudes of sacrificial volunteers could inflict such mayhem on the invaders that the Allies would agree to a negotiated peace.

To compel Japan to surrender, the Allies assembled a force of five million men. These were largely American but also included three British Commonwealth infantry divisions, a contingent of supporting RAF fliers and the British Pacific Fleet. Troops idled by the end of the war in Europe were being shipped to the Pacific theater as quickly as the transport system allowed. Seeking all possible help, the Joint Chiefs urged FDR, at his Yalta meeting with Churchill and Stalin, to exact Russia's promise to come into the war and join in the attack on Japan. The U.S. chiefs told the president and the prime minister to make whatever concessions were necessary to ensure USSR participation.

Meanwhile, Allied warships and aircraft were doing their utmost to reduce Japan to a wasteland. Almost with impunity navy ships cruised along the coasts and shelled inland targets. Carrier-based aircraft heaped destruction on airfields, naval bases, shipping, rail lines and communications. Superfortresses added another form of attack to their high-level daytime bombing. At night they swept in at low altitudes to drop thousands of incendiaries on Japanese cities. In one raid the Superforts burned out sixteen square miles of Tokyo. Five other cities were similarly devastated, which left thousands dead and hundreds of thousands homeless.

Magic decrypts now seized center stage. They revealed that Japanese diplomats, blind to the fact that Stalin had already pledged to come into the war on the Allies' side, had traveled to Moscow to persuade the Russians to act as intermediaries for peace negotiations. The decrypts also made clear that although a peace faction had been formed at the upper levels of power, its leaders could not prevail against the military hierarchy.

The sticking point for the Japanese, as it had been for the Germans, was the idea of "unconditional surrender." Early in the war, on the final day of the summit meeting in Casablanca, Roosevelt had used the term when ad-libbing in a press conference. The extreme term greatly distressed Winston Churchill, who recognized how it would block any hope of a negotiated surrender. Once an Allied leader pronounced it, though, the term stuck. Anyone questioning it ran the risk of being judged guilty of "appeasement." For the Japanese it had the inadmissible meaning of dethroning the emperor.

The concept of unconditional surrender was discussed when Truman arrived in Potsdam, Germany, for his first Big Three conference, as recounted by David McCullough in his
Truman
biography. Churchill and Stalin were in favor of easing it to allow the monarchy to be preserved. Along with his chief advisers, Truman was not so sure. The president had his reason for thinking the Japanese would agree to an outright unconditional surrender. He had delayed the start of the conference to July 17 because he knew that, on the day preceding, the first atomic bomb was scheduled to be tested at Alamogordo, New Mexico. The test was successful, meaning that the Allies now had the power to end the war on their own terms. Churchill was told explicitly that the "babies" had been "satisfactorily born." Truman told Stalin, almost as an aside, only that the Allies now possessed "an entirely novel form of bomb, something quite out of the ordinary, which we think will have decisive effects upon the Japanese will to continue the war."

Truman, Churchill and the representatives of China issued the Potsdam Declaration,, offering Japan "an opportunity to end the war" before Allied military power completely destroyed the Japanese forces and reduced the homeland to utter devastation. The declaration took into account what decrypts had been disclosing about the divided states of mind among Japanese leaders, demanding that the nation decide "whether she will continue to be controlled" by those who had brought her "to the threshold of annihilation" or whether she would follow "the path of reason." It set down hard terms for the disarmament of the military and the elimination of those who had "deceived and misled" the people. It did limit the call for an unconditional surrender to "all of the Japanese armed forces."

With the militarists still in control, however, the offer was rejected out of hand.