Codebreakers Victory (43 page)

However it was, the staunch defense at Kohima and Imphal by Slim's Fourteenth Army allowed him to implement a new strategy. He had troops at his Arakan command on Burma's west coast that he could transfer to the Imphal-Kohima battles. He thought at first of moving the reinforcements by road and rail. When, however, he learned from his intelligence officers the full extent of the Japanese commitment to that area, he knew the shift must be done by air. He had U.S. and British aircraft at his disposal, most of them C-47 Dakotas. He needed C-46 Commandos from the Hump route—planes each of which could carry a load equivalent to that of thirty Dakotas.

Mountbatten took the initiative and secured the loan of the Hump aircraft. The airborne transfer of the coastal divisions to Imphal, according to Slim, brought the turning point. They arrived just in time, lifted the two sieges in vicious fighting and checked the Japanese short of replenishing themselves from Allied supplies. The Allies' defeat of the Fifteenth Army was aided as much by hunger and disease as by ammunition and bayonets.

The codebreakers' emphatic role in the turnaround was spelled out by Slim in talks with Winterbotham when the Ultra official traveled from Bletchley Park to check up on the CBI situation. "General Slim told me," Winterbotham wrote in
The Ultra Secret,
"that the intelligence from Ultra about the Japanese forces had been invaluable throughout the campaign, but the real triumph had been the information which led up to the final attack by the Japanese at Imphal and Kohima. It had become very evident from Ultra that the Japanese supply position was desperate and that their attack was being planned to capture the Fourteenth Army supply depots, so as to keep the Japanese army 'in business.'"

Winterbotham also learned that the codebreakers had shown "that the Japanese air force in the area had dwindled so as to be practically useless." The information was put to practical use in two ways. Allied air crews were able to supply the Fourteenth Army from the air without being menaced by Japanese fighters, and the decision to use the Hump cargo planes to fly in a whole division was made with the knowledge that it could be done without enemy interruption.

This time, the BP emissary concluded, "the Japanese retreat was for good."

 

 

The Recapture of Rangoon

 

To keep pressing the attack, Slim drew up new plans. The battles at Imphal-Kohima had crushed Japan's Fifteenth Army. Now he was faced by the Thirty-third Army, which he resolved to smash as well. He sent his troops south toward the cities of Mandalay and Meiktila. However, "it was not Mandalay or Meiktila that we were after," Slim wrote in his memoir, "but the Japanese army."

He devised a grand deception, relying on his Sigint teams to tell him if it was succeeding and whether or not it had been detected.

His scheme was to engineer his own Chindit-style end run penetration to block the Japanese retreat. Alan Stripp's memoir,
Codebreaker in the Far East,
has detailed the elaborate precautions Slim took in order to keep his encirclement a surprise.

Since the operation was to take place in Burma's dry season, the hundred-mile swing to the west had to avoid revealing itself by plumes of dust kicked up by the advancing men and armor. The construction crews laid a track of asphalt-impregnated dust-gathering hempen cloth at the rate of a mile a day. In the mountains they cantilevered tracks out from the cliff faces. To cross streams they installed seven prefabricated bridges. Teams of elephants were brought in to fell trees, help with the bridge building and collect timber for five hundred river barges used to transport troops and equipment. Drums filled with gasoline were floated on rafts of empty drums lashed together. The RAF prowled the skies to prevent any wandering Japanese plane from spying the end run.

Beaten in the Imphal-Kohima battle, the Japanese had retreated to the east side of the Chindwin River and stood ready to repel the Fourteenth Army's attempt to cross it. While they waited, Slim pulled off the second phase of his deception plan. He left a single division of his army there, along with a dummy headquarters and a radio communications unit that whipped up a storm of fake transmissions to suggest the busy traffic of forces readying for the crossing. The other divisions took to the concealed roadway, crossed the Chindwin one hundred miles south of the key town of Mandalay and took positions across the Japanese escape route.

Due to his secret encircling maneuver, the Thirty-third Army disintegrated. Small units tried to escape through the jungle and down the streams, but most of them were hunted down and wiped out.

Combining overland drives with airborne and amphibious assaults, the Allied armies converged on Rangoon. On May 2, 1945, an RAF pilot flying over the city saw a message written by Allied prisoners of war on top of their jail. It read JAPS GONE. The flier landed his plane at a nearby air base and walked into the city center, where he was greeted by the POWs. His cheeky report on the incident claimed that Rangoon had been taken by the RAF.

The Japanese had left the port sabotaged and smashed. Slim marshaled engineers and laborers to repair and reopen it. "They succeeded beyond my hopes," he wrote. "In six weeks we had 3,000 tons a day coming over the patched-up wharves; the maintenance crisis was passed."

 

 

One More Army to Destroy

 

Although the war in Europe was now over and the Allies' climb up the Pacific island ladder far advanced, generals who did not know about the atomic bomb had no choice but to anticipate months, possibly even years, of further warfare in Asia. For the generals of the CBI theater, this meant they still had to defeat another Japanese army, the largely intact Twenty-eighth, cornered in eastern Burma by the Allied victories. The aim of Japanese commanders was to save the army and withdraw it so it could fight again in Malaya, Singapore or even in the homeland. The result was the Battle of the Breakout.

Again, codebreakers and intelligence teams gave the Allies an enormous advantage. Allen has written of Lieutenant General Francis Tuker, who was directing the Allied attack, "Naturally enough, his Intelligence had given him the entire picture on a plate."

The richest intelligence source was, once more, a captured document that gave the Allied leaders the clues they needed to thwart the Japanese and destroy the Twenty-eighth with a minimal expenditure of their own troops. In the foothills northeast of Rangoon, a patrol of Gurkhas ran into a Japanese contingent, killed a number of them and drove off the rest. Among the debris the Japanese left in their retreat was a leather dispatch bag. By the time the Gurkhas found it, it was soaked by the monsoon rains. A British intelligence officer, Lieutenant L. Levy, and a U.S. nisei sergeant, Katsu Tabata, carefully dried the papers from the bag, pieced them together and translated them. They disclosed the Twenty-eighth's breakout plans, including the routes they meant to follow. From that point on it was, as military historian S. W. Kelly noted, "largely a gunners' battle." The Allies massed artillery at main points in the Japanese passage and used metal rather than men to massacre the retreating forces.

Unknowing, disbelieving pockets of Japanese troops were still resisting well after the atomic bombs were dropped and the war ended.

In winning the China-Burma-India war, the Allies did more than stop the march to Delhi. They tied, up the more than 300,000 troops Japan sent there and killed three-fifths of them, allowing only 185,000 to return home. They routed the subservient armies whose victories would have turned Burma and India into Japanese puppet states. They kept China in the war. In so doing, they achieved at least one of the U.S. goals: in the weeks before Hiroshima, U.S. China-based planes did join in the bombing of the Japanese home islands.

As for the codebreakers' contribution to the hard-fought turn toward victory in the CBI, Hugh Denham, a BP-trained analyst who served in India, has told of Louis Mountbatten visiting his unit at war's end and saying of the CBI cryptographic teams that they were "worth ten divisions." Hyperbole, of course, but nonetheless a gratifying commendation for the men and women who spent countless hours, often in unspeakable conditions, to wrest the contents out of the multiple codes used by the Japanese and to read for Allied commanders the minds of their opposing brass.

 

 

 

17

 

Europe: The Bitter Fruits of Complacency

 

 

Robert A. Miller's book
August 1944
claimed this was the climactic month of the war in Western Europe. At the month's beginning, the Allies' hold on their beachhead in Normandy was still tenuous. The pivotal town of Caen had not been taken. The Americans were bogged down in the
bocage.
Everywhere the Allies were well behind their planned schedules of advance.

By the month's end, all had changed. Caen had fallen; the Americans had held off the mad offensive Hitler had ordered at Mortain and Patton was making ground-eating drives toward the German frontier. Paris had been liberated. The entrapment at Falaise had seriously weakened the Wehrmacht.

Euphoria set in among Allied leaders and lower ranks alike. Official summaries included statements such as "The August battles have done it; have brought the end of the war in Europe in sight." December 31 was marked as the ultimate date for victory. GIs sang, "I'll be home for Christmas."

Unfortunately, along with the euphoria came complacency, overconfidence, carelessness. Signals intelligence was nevermore complete or timely, but it was in crucial instances disregarded. Ambitious plans would not be altered because of a few misgivings conveyed by Special Liaison Units.

Churchill, for one, was by no means convinced that the scene on the continent was as rosy as it appeared. He read the Ultra reports of how masterfully the Germans were pulling their forces together to form a new defense line from the North Sea littoral to the Swiss border. Freshly formed fighting divisions were being scraped together by combing able-bodied men out of rear echelon troops. Underused Luftwaffe and navy personnel were being reassigned. Men not previously thought to be soldier material were being sworn in and hustled forward to fill in the gaps while battered panzer divisions were withdrawn to be reorganized and reequipped. Decrypts told him of divisions being transferred from the stalemated front in Italy. German war production, adroitly dispersed by Albert Speer, was turning out more materiel than at any previous time of the war. Most significantly, the prime minister noted that the Allies, in their eastward sweep, had still not captured a major usable port. Although Montgomery's armies had taken the port of Antwerp, finding it surprisingly intact, the harbor could not be used until the winding Schelde River estuary that connected it with the sea, as well as the islands offshore from the estuary, could be wrested from German control. Churchill saw these worrisome details, and no doubt growled into his sherry, but by then he was trying to leave the direction of the war to the generals.

Another disturbing element, as Anthony Cave Brown has noted in his book
Bodyguard of Lies,
was that having pulled off their enormous ruses to fool the Germans about the landings in Normandy, the Allies had no grand deceptions left. Now it was frontal assault against dug-in defenses, conventional arms rather than skillful artifice, and the war would, as Brown expressed it, "deteriorate into dull carnage." The progress was slow and the casualties were heavy, far heavier during the plotless march to Germany's borders than in those heady times when subterfuge dominated.

The Allied leaders could not claim, though, that they lacked for knowledge of German intentions. For example, a flood of decrypts should have made clear to Montgomery the importance the Germans placed in holding the approaches to Antwerp. Those coastlands north of the city denied the port to the Allies. They also provided an escape route for the Germans' Fifteenth Army, strung out along the Normandy coast. But Monty, with the concurrence of Eisenhower, regarded the Schelde as an annoying diversion from his main objective: to push on eastward toward the Ruhr and the Reich heartland. The First Canadian Army, which he assigned to clear the estuary, was not strong enough to do the job. Not until eighty-five days later did the first Allied transports finally enter Antwerp, and in the interim Allied operations were greatly handicapped by problems of supply. In a moment of refreshing candor, Montgomery was later to admit that in underestimating the difficulty of opening up the Schelde he had made "a bad mistake," adding, "I reckoned that the Canadian Army could do it
while
we were going for the Ruhr. I was wrong."

A serious setback for the Allies, in blood and in spirit, came in September when Montgomery decided he could speed his penetration into the Reich and bring the war to an end in 1944 by dropping paratroops and glider crews behind the German lines in Holland. He code-named his plan Market Garden and won Eisenhower's approval of it. The plan called for a British airborne division to land near the town of Amhem, capture the bridge there over the Rhine River and hold it until an armored relief column could arrive. Two American airborne divisions were to seize key bridges leading up to Amhem while the armored British XXX Corps broke out of its beachhead on the Meuse-Escaut Canal, more than fifty miles to the rear, and drove to Amhem. If the operation succeeded, it would forge a corridor through the German defenses and across the Rhine.

As Peter Harclerode has detailed in his book
Arnhem,
the plan was flawed from the beginning and became "a tragedy of errors." In the first place, it began too late. Launched sooner, it would have caught the Germans reeling back, disorganized by their defeats in Normandy. By the time Eisenhower had stopped vacillating in his support and Montgomery had pressured for every ounce of scarce supplies he could obtain, the opportunity was gone. The Germans had firmed up their defenses.

Then the operation was undertaken too hurriedly; commanders were given only six days to prepare, not enough time for them to reconnoiter what they would be up against. The British commander sensibly sought to have the paratroops land near Arnhem, but the RAF, believing that antiaircraft fire there would be too intense—an unfounded fear, as it turned out—would agree only to drop zones eight miles away. The number of planes was inadequate to carry out so large an operation, with a result that the paratroop and glider landings were spread out over three days, losing much of the advantage of surprise. Among other errors, the field radio equipment was too low powered to overcome the distances involved and enable the various outfits to communicate with each other.