War of Shadows

by Gershom Gorenberg

  Dudley-Smith’s experiment with the flagship code had given him a calling in life, one that finally gave his mind ample sustenance: finding out whether Britain’s own codes and ciphers could be broken, and whether the enemy was doing so.

  In 1941, freshly married, he was moved to Bletchley Park to work under Travis and take the freshly created posts of cipher security officer and secretary of a new committee on the subject that brought together the navy, air force, army, and Bletchley Park. Travis, the reigning expert on finding flaws in British codes, was too busy as an administrator. Dudley-Smith filled the gap. During that year, his responsibility expanded to the communications of allies and almost-allies. He showed, for instance, that the US merchant marine cipher was “pathetically simple” to break, a warning passed on to the US Navy. Three months later he checked and found that the Americans were still using the transparent cipher. After the second warning, the cipher was finally switched.19

  IN THE SPRING of 1941, the Foreign Office sent a query. Intelligence cooperation between Britain and the United States was growing, and there were two ways to trade information—via the American embassy in London or the British embassy in Washington. The US embassy would use American diplomatic ciphers to report home. But was that safe? At the Ministry of Economic Warfare, in charge of denying Germany raw materials, the man in charge of economic intelligence wanted to know. The Foreign Office asked Menzies, who forwarded the question to Travis, who would have most likely asked Dudley-Smith to get answers.

  A note initialed by Travis came back to the Foreign Office. It said American diplomatic telegrams to Washington were safe from interception—by the Axis. The unstated implication was that American traffic traveled on an intact British undersea cable.

  As for the wider question of US diplomatic codes and ciphers, this was delicate. The State Department had three code systems, the GCHQ note said. One system was used rarely, for the most secret messages. So far it was unbreakable.

  “The second-best book,” used more often, for material that was just slightly less secret, was “legible but patchy.” GCHQ could read some messages that the enemy couldn’t solve, but the opposite was also true. For “third-grade material,” the State Department used another code. It was “probably fully legible,” meaning that both British and Axis codebreakers could read anything sent in it.

  The big difference, the note said, was that Britain was able to intercept many more American diplomatic cables than the enemy was.

  So it would be a bad idea to tell the State Department to use its best code for anything that needed to be secret. Doing this would mean that “we lose all American traffic.” The enemy would be denied less American information because it was getting less to start with.20 Part of the job of the gentlemen and ladies at GCHQ was reading American mail. Knowing what an almost-ally thought, particularly what it thought about you, was valuable. No warning was sent.

  Not then. But two months earlier in Madrid, British ambassador Samuel Hoare—another pro-appeasement former cabinet minister exiled to a diplomatic post—had passed a “hint” to American ambassador Alexander Wendell. Hoare had heard from “friendly sources on which I rely” that American codes and ciphers “generally used even for confidential matters are vulnerable.” The US embassy in Spain rarely used the best, safest system, Hoare had heard.

  The State Department had asked the Foreign Office in London about this. On this occasion, Menzies had apparently forgotten to check with his codebreakers. He had approved a letter recommending to State that when communicating with Madrid, it should use only its best cipher “for confidential and delicate subjects.”21

  If the State Department took this advice, it apparently did so only for messages to Spain. When GCHQ was finally asked about American security, US diplomats were still sending secrets in the second-best code, and both the British and the Axis were still breaking it. The British were breaking it more often.

  STILL, BLETCHLEY PARK’S real war was with the enemy’s codes and with Enigma most of all. It was a war that took place on paper, in the whirl of the bombe wheels, and most of all in the mind.

  As the big war outside grew, so did the quiet war of the codes. Enigma keys proliferated, serving different tentacles of the Nazi military and bureaucracy. In the summer of 1940, Bletchley Park identified the key used by the German railway administration. It vanished, then reappeared early in 1941. The Nazi railway people used a model of the Enigma machine without a plugboard, which made it easier for John Tiltman to crack the key. By March the number of railway messages multiplied. Most gave instructions about moving German troops and supplies across Europe, to the east.

  At the beginning of January, Hitler sent the German air force’s Fliegerkorps X—the 10th Air Corps—to Sicily to lend support to the crumbling Italian army in Libya. The corps got its own Enigma key, which Hut 6 at Bletchley Park labeled Light Blue. German code clerks presumably used some of the same stock phrases in Light Blue as they had in Red, the main air force key. Those phrases could serve as cribs, the bits of text used to set up the bombes. Sometimes whole messages sent in Red or Light Blue were resent in the other, a gift to codebreakers. By the end of February, Gordon Welchman’s crew at Hut 6 was reading the new key.22 (Welchman was at home too little; his wife would begin to believe he was seeing someone else. In fact, he was carrying on a love affair with his work. It was exciting; it served his country; he was superb at it. His Hut 6 team was “the happiest group at Bletchley,” he would recall. And like a man with a secret lover, he could tell almost no one what he was up to.23)

  But the German army’s keys remained unconquered. Radio messages, in any case, would not have revealed Hitler’s meeting on February 6 with the general he had decided to send to Libya: Erwin Rommel.

  At most, reading army Enigma would have allowed Hut 6 to hear the echoes of the orders given to Rommel. Rommel was to command two German divisions, one of them a tank division, along with Italian mobile forces already in Libya. His job was to prevent British conquest of western Libya. He was subject to the Italian high command, though he could appeal to Berlin if need be. His German troops would begin arriving in Tripoli by ship in mid-February. Rommel would fly in before them and begin reconnaissance. But his divisions wouldn’t be up to full strength until mid-May. At least until he had one full division, he was to stay in the Tripoli area. Much further east, the Italians were supposed to hold a north-south line below the Gulf of Sirte, which divided western Libya—Tripolitania—from Cyrenaica in the east. Hitler had other conquests in mind than Africa. Rommel’s job was to prevent an Italian collapse.

  Yet even if army Enigma had been an open book, knowing those orders would have been little help to Churchill, the war cabinet, or General Wavell at the Middle East Command, because Rommel had no intention of letting orders get in his way.

  By the time Rommel landed in Tripoli, the British forces in Libya led by General O’Connor had swept into Benghazi. Rommel had a passion for small planes. He took a six-hundred-mile flight out across the desert to look down at the meager Italian forces at the coastal village of Sirte. He started sending German forces forward as soon as they got off their ships. Without a stronger defense, Rommel believed, the British army would soon be on the outskirts of Tripoli.24

  Wavell had no idea of what Rommel was up to, but Rommel was also mistaken about British plans.

  Churchill and Wavell were anxiously expecting a German intervention on an Italian front—in Greece. Britain had pledged in 1939 to defend Greece, and had signed a mutual assistance treaty with Turkey. If it didn’t help Greece now, Turkey would see that British promises were worthless. And if Turkey decided that the least harmful gambit was to allow German forces to pass through its territory, a German army would be in Vichy-ruled Syria, ready to push through Palestine and on to the Suez. Greece was the northern gateway to the Middle East, and Germany was preparing a battering ram.25

  “It is estimated by British intelligence that in Rumania the Germans have 515
combat… airplanes, including 100 dive bombers recently arrived, as well as 23 divisions, including four armored ones,” Fellers radioed the War Department in late February. “All African operation is overshadowed by the entire Balkan situation,” Fellers reported. “The British are postponing the proposed advance into Tripoli.”26

  A week later, he sent an update. At a spot called Agheila, German armored cars had raided the forward British position in Libya. The British admitted that “these eight-wheeled armored cars are superior” to any they possess, Fellers said. But it was a skirmish; it didn’t change the big picture. Meanwhile, he said, Australian, New Zealand, British, and Indian divisions were getting ready to embark for Greece.27

  “Dan and his general flew in unexpectedly. General Neame is taking over command of Cyrenaica,” Hermione Ranfurly wrote in her diary.28 Philip Neame received a stripped-down force, barely more than a placeholder on the map: half of a newly arrived, inexperienced British armored division on the front line, and an equally raw Australian division, part of it holding Tobruk. Wavell wrote to Churchill, explaining his decisions: it was 471 miles from Tripoli to Agheila and another 175 miles from there to Benghazi; for most of the route there was no water; and the enemy was short on transport vehicles. The new German force might try to take Agheila, but wasn’t likely to try for Benghazi till after the fierce heat of summer. Wavell said he was ready to take “considerable risk in Cyrenaica… to provide maximum support for Greece.”29

  Wavell could almost have read the minds of the German and Italian general staffs. Rommel flew to Berlin in March to report. Field Marshal Walther von Brauchitsch, commander in chief of the German army, denied his request for reinforcements. If Rommel wanted to move a bit forward, he should wait till the end of May, when his two divisions would be complete.

  Rommel returned to Libya, and promptly sent a battalion to grab the British fort at Agheila. He radioed a request for the air force to send a squadron of bombers to Tripoli to help him. The answer was no, “on the grounds that center of operations lay elsewhere.” Since this was an air force message, it went out in a key of Enigma that could be read at Bletchley Park. Hut 3 finally had a direct teleprinter line to General Headquarters Middle East for “special intelligence”—cover name for Enigma material—and sent word to Wavell.30

  “Elsewhere” clearly meant Greece. Special intelligence confirmed Wavell’s evaluation.

  Rommel, however, was undeterred. He gave orders to seize the next British position in the desert. When he saw the British forces retreating, he decided he’d rush forward and “make a bid to seize the whole of Cyrenaica at one stroke.”

  General Italo Gariboldi, who’d just replaced Graziani as the Italian commander in chief in Libya, “berated me violently” for ignoring direct orders from Rome and warned that “the supply situation was far too insecure,” Rommel would recall.31 Gariboldi was right: food, ammunition, arms, and fuel all had to be brought by truck from Tripoli, after coming by ship across the Mediterranean from Italy. Even water had to come by truck. A division required 350 tons of supplies a day. The German army was using two-ton trucks. The further Rommel went, the further the trucks had to come to reach him, and that took even more fuel. The German general staff had estimated that in Operation Sunflower—Rommel’s mission in Libya—it would take ten times as many trucks to supply a division as in a bigger operation planned for Europe.32

  Yet when Rommel exercised his option to appeal to Berlin, he received approval to go ahead.33 This message would have gone in an army Enigma key. Hut 6 could not read it. It made little difference. Neame had already ordered his meager forces to retreat. By April 4, the Germans were in Benghazi. The Arab and Jewish townspeople who’d welcomed the British as liberators were again under Axis rule.34

  “There’s a horrid rumor that Germans have arrived in North Africa,” Hermione Ranfurly wrote. “Thank God Dan has a staff job.” A few days later, home sick from work, she heard a knock on the door. It was Lady MacMichael, wife of the high commissioner of Palestine, who was staying with General O’Connor’s wife while he was in the desert advising Neame. MacMichael asked about her health, “talked about the weather, fidgeted around the room and looked out the window.” Suddenly she turned and said, “Your Dan is missing.” So were O’Connor and Neame. They’d been together, and might have been taken prisoner. “She went on talking but I did not really listen. After a while I thanked her for coming to tell me, gave her a hug and closed the door gently behind her.”35

  Rommel launched an attack across the hump of Cyrenaica, just as O’Connor had done but in the opposite direction. It stalled when one unit ran out of fuel to move its artillery. He rounded up thirty-five cans of gasoline and delivered them himself. Another unit went missing in the desert. He took off in a light plane to look for it, nearly landed by mistake among British forces he mistook for his own, and got shot at by Italians who didn’t recognize his German aircraft. Nonetheless, he pushed onward to the Egyptian border, down Halfaya Pass, and took Sollum. “Probably never before in modern warfare had such a completely unprepared offensive as this raid through Cyrenaica been attempted,” he would write afterward. He’d shown again that will power and commanding from the front, not the calculations of desk officers, brought victory. He believed he had “an excellent springboard… for a possible summer offensive against Alexandria.”36

  At General Headquarters Middle East in Cairo, Wavell expected that offensive. He told Fellers that “he did not, repeat not, believe the German forces could get closer than one hundred miles from Cairo within the next two months.”37 This was phrased as an optimistic estimation. Fellers no longer needed to send his dispatches through the Cairo embassy’s civilian code room in State Department codes; he’d finally received the military attaché code and cipher tables, William Friedman’s clever invention.38

  Rommel’s position at the edge of Egypt was real, but his success was part desert mirage. He’d defeated a British force that, from the start of his campaign, was much weaker than he’d known. And far behind his front line, the Australians still held Tobruk. He needed that port for supplies in order to advance; Benghazi was 250 miles further away from his forward position at Sollum. His attacks on Tobruk failed. He found himself in an old kind of battle, the kind he recalled from the previous war and always sought to avoid, against men dug into fixed positions. He wanted to move, to race forward. At Tobruk, too many of his men were wounded or killed. The fault for that wasn’t his, he wrote. “The high casualties suffered by my assault forces,” he explained, “were primarily caused by their lack of training.”39

  General Franz Halder, chief of staff of the German army, wrote in his notebook that Rommel “was in no way up to his operational task,” that the engines of Rommel’s tanks needed replacing, that it was impossible to meet Rommel’s demand to be resupplied by air since planes landing in North Africa “find no fuel for the return flight.” He mused about how to rein in “this soldier gone stark mad.” Nazi propaganda chief Joseph Goebbels, meanwhile, promoted Rommel publicly as the incarnation of German victory.40

  HUT 3 SENT the word early on April 5: German air force units in Romania had received orders to start hostilities at 5:30 a.m., Greenwich Mean Time, the next day. Zero hour for the German Twelfth Army, poised in Bulgaria on the borders of Yugoslavia and Greece, was the same.41

  From British commanders in Greece came a stream of “sitreps”—situation reports—for Wavell. The words “lost” and “retreat” and “in enemy hands” and “evacuation” repeated. The Germans were advancing on Salonika, Greece’s second city, in the northeast. The last train from Salonika was leaving. The New Zealand division was dropping back to the passes at Mt. Olympus. The Yugoslav Second Army was asking the Germans to end hostilities. Enemy air action was spotted at Mt. Olympus. (The sitrep did not say whether Zeus, Hera, and Aphrodite had joined the refugees on the roads south.) The Germans demanded complete Yugoslav surrender, “otherwise ceaseless bombing of towns will follow.” The Greek
military command had broken down, and all Greek forces were in “complete disorganization.”42

  The decoded sitreps were typed up in only six or nine copies and marked “most secret,” equivalent to “top secret” in the United States. Copies reached Fellers’s desk. He told the War Department that General Henry Maitland Wilson, in command in Greece, “is retiring to Thermopylae, where he can hold out a week.”43 (Thermopylae, just north of Athens, was the pass where the Spartan king Leonidas and his few hundred men nearly stopped the army of Persia twenty-four hundred years earlier.) Before Wilson’s week was out, Greece had surrendered and the Royal Navy was evacuating what was left of Wilson’s army. Yugoslavia had already surrendered. One scrap of Europe remained in Allied hands, the Greek island of Crete, a dolphin-shaped piece of land stretched out in the Mediterranean almost halfway from Athens to Tobruk. Crete’s location showed how artificial the sharp distinction between Europe and the Middle East actually was.

  “KIND BONNER FELLERS has wired the American legation in Rome asking for help,” Ranfurly wrote. The young countess was trying to find out if her husband was in fact alive in Italian hands. She met Fellers for lunch and found that “he is sad because his friend, Colonel Brower, has been killed while flying an aeroplane up from Takoradi.”

  Gerald Brower was an American air officer assigned as an observer to the Royal Air Force in Cairo. He’d flown to Takoradi, in the British colony of the Gold Coast in West Africa, because Britain was shipping warplanes that it received from America there. In Takoradi, they were assembled, then flown by RAF pilots in hops across the continent to Khartoum and on to Egypt. Brower wanted to check whether American pilots could deliver planes to the Middle East directly by flying them from Brazil to Takoradi, the shortest route across the Atlantic.