The British were careful, in carrying out this ravaging of the Axis marine, to preserve the security of Ultra. When decrypts specified the course of an Axis transport, an RAF reconnaissance plane would take off from Malta and seem, as merely part of a routine patrol, to happen upon the vessel. Meanwhile, a Malta-based submarine or bomber would already be on its way to intercept the ship. As Hinsley recalled the results in a 1996 reminiscence, "The Germans and the Italians assumed that we had 400 submarines whereas we had 25. And they assumed that we had a huge reconnaissance airforce on Malta, whereas we had three aeroplanes!"
A man with the sharp intelligence of Albert Kesselring, Hitler's commander in chief in Italy, was suspicious of the "extraordinary losses incurred during sea transport." He "suspected that the times of our convoy sailings were betrayed." But instead of questioning broken codes, he blamed the sinkings on "the efficiency and wide ramifications of the enemy system of sabotage."
The results for Rommel were catastrophic. He faced the Eighth Army short of ammunition, with rations for his troops at a low level, and so deprived of gasoline that he was robbed of freedom of movement. As he commented in The Rommel Papers, which his wife and son put together after his death, "The battle is fought and decided by the Quartermasters before the shooting begins." He leaves no doubt that with adequate supplies, including a sufficient tonnage of gasoline, he could still have defeated an enemy that was "operating with astonishing hesitancy and caution." As it was, El Alamein became, as he entitled one of his chapters, the "Battle Without Hope."
Added to his troubles was his vulnerability to the sort of deception he had earlier used against the British. Wanting Rommel to believe Eighth Army forces were being built up in the south, Montgomery ordered the creation of dummy battalions, with fake tanks, bogus artillery and troop simulations that went so far as to have balloon soldiers sitting on inflatable latrines. A masterstroke was a mock water pipeline made up of discarded gasoline cans. It was left unfinished to fool the Germans into believing the attack would not come until the line was completed.
Rommel, a sick man, lulled by Monty's trickery, had actually returned to Germany for treatment when the Eighth Army struck. His second-in-command, fat General Georg Stumme, trying to cope with the complexities of combat, died of a heart attack. Healthy or not, Rommel flew back to resume command.
Montgomery's critics can't deny that he divined the most likely point of Rommel's attack: the Alam al-Halfa ridge. He prepared to meet and destroy Rommel's armor there. Four days after he'd made this decision, Ultra decrypts confirmed that a thrust against the ridge was exactly what Rommel intended. Monty's acute military analysis, backed by the codebreakers, gave him the victory in the defensive phase of El Alamein.
When the Eighth Army went on the offensive, however, Montgomery's Master Plan turned out to have serious flaws. Needing to break through in-depth minefields, Monty planned to have sappers clear a narrow channel through which his infantry and armored divisions would pour during the first hours of the offensive. The plan went awry when the minefields proved to be a tougher, more time-consuming problem than he'd anticipated. His infantry and armor had to wait until a defile was cleared. Then the mass of troops and tanks trying to crowd through it created confusion, causing further delays and heavy losses. He had, in effect, to throw away his Master Plan and improvise his further moves, but he did this with calm authority and, in the end, carried the day.
Rommel, his armor all but immobilized by lack of fuel, had no choice but to concentrate on evacuating his armies to avoid annihilation.
Here that "astonishing hesitancy and caution" he had observed of Montgomery came to Rommel's rescue. To the amazement and dismay of the onlookers at Bletchley Park, Montgomery made no move for three days after Rommel had started his retreat. He seemed so dazzled by his victory that he could not bring himself to order the end runs that could have trapped the exhausted, near-helpless Afrika Korps, and send them into prisoner-of-war camps. In his memoir Monty blamed heavy rains for his failure to overtake Rommel, even though the rains did not begin until after those first three days of idleness. However it was, the Afrika Korps kept ahead of belated British sorties and reached Tripoli. They were headed there at the time of Anglo-American landings in French North Africa and were available to continue the war in North Africa for four more months of brutal fighting.
The Afrika Korps: Ultra Tightens the Noose
In 1942, after the U.S. had joined the war, Anglo-American planners held long discussions on how to conduct joint future campaigns. The Americans argued for a cross-Channel invasion in 1943. Knowing how much preparation was needed before that attempt could be made, the British advocated that the first substantial combined operation should instead be a series of North African landings. Agreement was reached and a timetable set for the autumn of 1942, with a little-known American general, Dwight D. Eisenhower, in charge.
It was just as well that the British won the argument. The North African landings showed up countless fumbles, mix-ups and snafus that needed to be corrected before taking on the Germans in northern France.
The North African expedition was, in fact, a tissue of bungles. The primary objective was to seize the Tunisian ports of Bizerte and Tunis, to prevent the Axis from using these ports that provided the nearest and best harbors for transports from Sicily and Italy and the best exits for an evacuation. To achieve the objective, the British felt sure, the landing should be made as far east as possible, hard on the Algeria-Tunisia border. The Americans were cautious about venturing so far. All sorts of fears entered in—among them the threat that Hitler might press France and Spain into allowing German passage through to capture Gibraltar, whose fall could maroon troops east of the Rock. To forestall any such eventuality, the Americans urged at least one landing in Morocco, west of Gibraltar. With that safeguard, a Mediterranean landing could also be contemplated.
A compromise was reached. Operation Torch would be made up of three landings: at Casablanca in Morocco, and at Oran and Algiers in Algeria. After securing these sites, it was thought, Allied troops could speed across land to capture the Tunisian ports.
The trouble was that even the easternmost landing, in Algiers, was still 450 miles from Tunis. They were tough miles, much of the way through rugged mountain terrain. As canny Scots general Kenneth Anderson noted, the race for Tunis was lost before it began.
The November 8, 1942, landings came just four days after Rommel's defeat at El Alamein. In themselves they represented a magnificent achievement. An armada of some five hundred American and British ships had set out from ports as far apart as Portland, Maine, and Lock Ewe, Scotland, and had converged on North Africa without ever being touched by German U-boats. GC&CS decrypts showed that Axis leaders knew something big was afoot, but the messages also disclosed uncertainty about the destination. Italy, Sardinia, Sicily, Malta, the Aegean? The Axis commanders' most favored answer, as Ultra made clear, was that this was a convoy bound for the relief of Malta. The Allies used that information to carry off a bit of deception. The Mediterranean ships made a feint as though heading for Malta, then wheeled about and sailed for Algiers. The Axis commanders were fooled, and the landings were a surprise.
Aside from the Allies' own foul-ups, the landings went off more smoothly than anticipated. Only at Algiers did the French troops, supposedly loyal to the Vichy regime, show troublesome resistance. The Axis Mediterranean submarines managed only two attacks and damaged one ship. The German and Italian air forces were caught unprepared and did little to harass the landings. Neither France nor Spain acceded to a German march on Gibraltar.
One big problem remained: Tunis and Bizerte were objectives too far. Algerian roads were in poor condition. Railroad equipment was ancient and the tracks were of mixed gauges. The intended harelike dash was slowed to a tortoise crawl.
In addition, the planners seriously misjudged the Axis response. With Rommel beaten and the Russian offensive demanding close attention, the Allies doubted that Hitle
r would try another major gamble in North Africa. Even if he did, they believed, the preparations would take weeks. They were wrong on both counts. Hitler saw the danger in allowing the enemy to gain possession of the ports providing the best jumping-off point for an invasion of Sicily and Italy. The troops, armor and planes that Rommel had pleaded for and been denied now flowed in great numbers and with stunning speed into Tunisia. The capable, aggressive General Jürgen von Arnim was called back from the Russian front to share command with Rommel.
The Allies' push to reach the ports foundered. In addition to the surprising resistance by the Germans, winter rains turned roads into quagmires. Eisenhower called off the offensive, and both sides settled down to a winter spent gathering their strength. The race for Tunis had, indeed, been lost.
By the time the Allies resumed their drive into Tunisia, their intelligence advantage had become even more overwhelming. With mastery of Luftwaffe traffic a routine matter, BP cryptanalysts were also penetrating Wehrmacht Enigma ciphers. They had broken a new Enigma key that provided a fresh font of knowledge about Axis shipping. Italy's air force book code and Hagelin-encoded navy cipher were being quickly read. And Magic decrypts of Baron Oshima's reports continued to be helpful.
Axis commanders, by contrast, were reduced to guesses and hunches. An example of what this disadvantage could mean in battle came when Rommel—with his Afrika Korps troops safely dug in at the Mareth Line of old French fortifications in Tripoli—hurried west to join Arnim in organizing attacks against the Allies trying to hold the passes in the Atlas Mountains. Rommel's panzers succeeded in overpowering the untried American troops in the Kasserine Pass and fanned out into the plain beyond. He could have placed the whole North African operation in jeopardy if he had kept his drive going. But he had to guess at what lay ahead, and his guess was that the Allies were readying a counterattack that could trap him. Although his guess was wrong, he had no means of dispelling the uncharacteristic sense of caution that overcame him. When an American artillery division was hastily brought forward and began lobbing mortar shells onto Rommel's armor, he called off the offensive and withdrew through the pass. What was perhaps the greatest Axis opportunity in the campaign withdrew with him.
The battle for Tunisia was a series of gory thrusts and counterthrusts that continued through March and April and into May 1943. The code-breakers influenced the outcome in two critical ways. One was by keeping the Allied commanders informed about virtually every major action their Axis counterparts planned to take. The other was by directing the stranglehold on Axis supply lines.
Ultra's effects on strategic operations are exemplified by a March 3 decrypt that Hinsley described as of "decisive importance." It alerted Montgomery that Rommel, back with his old Afrika Korps troops, was organizing a surprise breakout from the Mareth Line against the Eighth Army on March 6. In a hard-driven day-and-night frenzy of activity, Monty used the three days to quadruple the forces in place at the point Rommel meant to strike. An in-depth massing of 470 antitank guns and 400 tanks was camouflaged to blast the Germans as they came forward. Rommel wrote later, "It became obvious that the British were prepared for us." After his attack had failed, the Desert Fox went home to Germany. This time he did not return.
Once more the Germans suspected that Enigma had been compromised. The British high command rebuked Montgomery for not making a greater effort to disguise the source of his intelligence. But again the suspicions were quelled, and use of the Enigma never wavered.
U.S. general Omar Bradley told, in his A General's Life, how the code-breakers helped the American soldiery regain a measure of respect from their British allies after the near rout of the GIs at Kasserine Pass. Arnim planned, on March 23, a counterattack against the U.S. II Corps at El Guettar. "Our front-line codebreakers," Bradley wrote, "picked up and decoded the order, giving us a full day's notice. . . . A second decoded message provided us further valuable details on the attack." So warned, the Americans "mauled the Germans and Italians . . . it was the first solid, indisputable defeat we inflicted on the German Army in the war. Kasserine Pass had now been avenged."
As for the Axis supply situation, Ultra decrypts made the clampdown by the Allies all but total. Arnim's armored divisions, like those of Rommel before him, were immobilized by lack of fuel. Many of his soldiers were soon existing on two slices of bread per man per day.
Without transports and control of the sea, Axis commanders could not manage a Dunkirk. When resistance ended and Arnim surrendered on May 13, Hitler and Mussolini had no choice but to abandon 275,000 German and Italian soldiers and all their equipment.
From Tunis, Alexander sent a message to Churchill: "Sir, it is my duty to report that the Tunisian campaign is over. All enemy resistance has ceased. We are masters of-the North African shore."
So ended an error-filled campaign that had resulted in more than one hundred thousand men—Germans, Italians, Britons, Americans, French—being killed, wounded or missing in action. As Rommel colorfully phrased it, "Rivers of blood were poured out over miserable strips of land which, in normal times, not even the poorest Arab would have bothered his head about."
But the campaign opened the underbelly of Europe to Allied attack, and it welded the Allied forces into a strong, unified and confident team. From the perspective of the codebreakers, the greatest significance was that the campaign proved to Allied generals the value of trusting their intelligence sources.
10
Turnaround in the Pacific War
For the six months following Pearl Harbor, the Japanese war machine was invincible. The U.S. islands of Guam and Wake fell within days after the Pearl Harbor raid. In the Philippines the Japanese sliced up the American and Filipino armies, forcing the Americans to retreat into the hopeless corners of Bataan and Corregidor and, in May 1942, to surrender. On the China coast, the American garrisons at Shanghai and Tianjin were seized. British-led forces were pushed out of Burma and Malaya. The Dutch East Indies yielded up their riches not only in oil but also in rubber, rice, timber and metals. The strategic stronghold at Rabaul in New Britain fell. The Japanese extended their Greater East Asia Coprosperity Sphere to include the whole arc of the central, south and southwest Pacific and were threatening the supply lines between the U.S. and Australia.
During those first months of 1942, the leadership that would direct the U.S. war effort in the Pacific had established itself. In Hawaii, Admiral Chester W. Nimitz had become the new commander of the Pacific Fleet. General MacArthur had been ordered to leave his besieged troops on Corregidor and escape to Australia in a torpedo boat. Moreover, the two commanders' cryptologic support teams were firmly in place. On Oahu, Edwin Layton, the fleet's chief intelligence officer, and Joe Rochefort were relieved to find that Nimitz refused to consider any shortcomings in their Pearl Harbor performance and wanted them to continue serving him. MacArthur had seen to it that his Cast cryptographers were spirited away to Australia on submarines before he himself left the Philippines, vowing, "I shall return."
In terms of cryptology, the explosive geographic expansion by the Japanese had one consequence that was to bring a decisive reversal in the course of the war. Japanese intelligence leaders knew that the security of their systems depended on regular replacement of the codebooks that were the basis of their nonmachine codes. They had planned to change their workaday naval code, JN-25, on April 1, 1942, but the distribution of their codebooks was made impossible by the twenty-million-square-mile spread of Japanese commands and the growing profusion of recipients. The date for the changeover was pushed back to May 1, then to the beginning of June. The delays gave Allied cryptanalysts those extra months to master JN-25.
In the windowless basement of the Fourteenth Naval District's Administration Building, known as "the dungeon," Joe Rochefort was on hand virtually nonstop. He paced around with a red smoking jacket over his uniform, both to keep him warm in the dank quarters and to provide the deep pockets he needed for his pipe, tobacco pouch and copies of mes
sages of special interest. His work uniform was completed with house slippers because the concrete floors hurt his feet. In addition to overseeing the direction-finding, intercept, and traffic analysis operations along with cryptanalysis, Rochefort had to manage the influx and training of new recruits now flooding into his cellar headquarters.
Of these newcomers the most bizarre was a contingent of musicians left jobless by the severe damage to their ship, the USS California, in the Japanese attack. To the amazement of Rochefort and Dyer, the band provided capable and even some exceptional additions to the team.
The new, closer cooperation between the Allied cryptographic units in the Pacific and in Washington quickly began to produce results. Gone were the cumbrous communications methods of the pre-Pearl Harbor days. Now the cryptanalytic units flashed new discoveries to each other via radio-teletypewriter links. Soon the analysts were solving some forty percent of JN-25's code groups, but since those were the most often used words and phrases, the meaning of a high percentage of entire messages could be determined, or at least guessed at.
In April the U.S. military, knowing how badly the American people needed a morale boost, planned what became known as "Doolittle's raid" on mainland Japan. Colonel James Doolittle would load sixteen B-25 bombers on the flight deck of the aircraft carrier USS Hornet, slip within five hundred miles of Japan, lead the bombers so they could drop bombs and incendiaries on Tokyo and other cities, and fly on to those parts of China still held by Chiang Kai-shek. To carry out this bold act, the Hornet was joined by Admiral William F. "Bull" Halsey on the aircraft carrier Enterprise and by several escort vessels. Fortunately, Halsey's crew included an experienced intelligence officer and intercept operators. When the task force was still well short of its five-hundred-mile goal, the intelligence team picked up Japanese radio traffic revealing that Halsey's ships had been sighted. Japanese leaders took almost two hours to overcome their shock and disbelief, but then their radio channels crackled with transmissions as they sought to organize a huge sea hunt. Halsey decided to launch the bombers sooner than planned but not so late that his precious carriers and other ships would be endangered. While the attacks themselves were mere pinpricks, the raid gave the U.S. the semblance of a reprisal for Pearl Harbor, a publicity bonanza and a lift to American spirits. FDR stirred imaginations by claiming the bombers were launched from Shangri-La, the mythical kingdom in James Hilton's novel Lost Horizon.
Codebreakers Victory Page 19