War of Shadows

by Gershom Gorenberg

  On April 9, German ships entered Norwegian ports—Oslo and Kristiansand in the south, Bergen and Trondheim further north, all the way up to Narvik beyond the Arctic Circle. They brought infantry troops. More ships unloaded invasion forces in Copenhagen, while German units crossed the land border into Denmark.

  The Phoney War in the West had just turned real.

  Until that day, both Norway and Denmark had carefully stuck to neutrality. Germany now said it was invading them in order to protect their neutrality from Britain. The sliver of truth in this irrationale was that seizing Norway really was a means to fighting Britain. Germany, with its own ports on the nearly landlocked Baltic Sea and the British-dominated North Sea, wanted Norway’s harbors as bases for war in the Atlantic. Besides that, the iron ore on which Germany’s arms factories depended came by rail from Swedish mines to the sea at Narvik. Taking the harbor guarded the supply line. As for conquering Denmark, that was a means to the end of taking Norway.

  The Danes surrendered the same day. Norway, outnumbered, tried to stop the invasion. Belatedly, Britain and France sent infantry forces to landing points north and south of Trondheim, and to Narvik.2

  HARRY HINSLEY’S INFORMATION wasn’t ignored because of his youth. His phone call was actually one item in a long list of intelligence clues of the coming invasion, beginning months beforehand and multiplying as the date approached. All were ignored. Three days before the landings, the top British diplomat in Copenhagen cabled the Foreign Office with information from his US counterpart: the American had a source who said the Germans intended to take Narvik. A Foreign Office desk officer added a memo, dismissing the report: “A German descent on Narvik is surely out of the question.” Two days before the landings, Britain’s naval attaché in Copenhagen sighted German warships heading north past Denmark. He cabled the Admiralty in London. A duty officer immediately showed the telegram to First Lord of the Admiralty Winston Churchill. Churchill read it and said, “I don’t think so.” Churchill did not believe Germany had the military ability to take Norway, and assumed the ships were intended for naval missions.

  The warnings went unheeded in part because they were reaching different offices and often weren’t shared. (Hinsley himself later wrote about this.) The Admiralty’s Operational Intelligence Center, at the other end of Hinsley’s phone line, was not getting full reports from MI6 or the Foreign Office. None of the clues were as explicit as they would later seem. They required interpretation. They had to be balanced against other signs, and they did not fit what the people reading them expected. The European division of Military Intelligence assessed that Germany would need at least 25 divisions to invade Norway and Sweden, and had information on only six deployed where they’d be needed. This assumed that a German offensive in Scandinavia would necessarily target Sweden and Norway together. The assumption was treated as a fact.3

  Beforehand, the clues of invasion were like the first symptoms of a rare disease. The doctors look for ailments they know well. Each receives lab reports from different tests, full of extraneous information. Afterward, when the patient is dead, when the autopsy takes place, all the doctors look negligent. All but the pathologist, who is proud of his judgment.

  For the invasion of Norway and Denmark, the German army and air force issued a new Enigma key for joint use. Hut 6 named it Yellow, and by April 15 was breaking it daily, often by dawn. After that, the translators in Hut 3 sometimes received intercepted messages less than an hour after a German wireless operator tapped them out in Morse code. The messages—about one thousand in little more than a month—told how German forces were organized, and what supplies they had and needed, and what they had done, and, most important of all, what their plans and orders were to do next.

  Both huts went over to three shifts a day, operating around the clock. Teleprinter lines were installed from Hut 3 to MI6 headquarters in London; from there, translated messages were forwarded to the three separate ministries responsible for making war: the Admiralty, the Air Ministry, and the War Office, which despite its name only administered the army. A safe way to get information from London to commanders fighting in Norway still hadn’t been devised.

  Before the serial number of each teleprinted item, the letters “CX” appeared. This was MI6’s standard label for reports from human agents. The messages from Bletchley Park would say things like “Source saw a document saying…” or, if the translator had only been able to puzzle out part of it, “Source saw a half-burned telegram…” The supposed source was code-named Boniface. He was said to be an anti-Nazi German, leader of a spy ring in the Nazi military.

  Here lay a paradox: The enemy’s purloined letters only have value if commanders and high officials know about them and trust their authenticity. Yet the process of stealing information is most secure when the fewest people know about it and, even then, don’t know how orders for tomorrow’s bombing missions could get from a German airfield outside Narvik to the Air Ministry in London.

  Denniston, Knox, and Welchman knew that “in theory Enigma was unbreakable; in practice it was broken only because the Germans [were] confident and careless.” If the Germans ever suspected that Enigma was being read and they cracked down, making sure everyone using it followed the rules, the game was up. So even when Bletchley Park sent out information read directly from German communications, it disguised the intelligence as reports from a spy. Yet British commanders and ministry officials didn’t put full trust in human agents—even the terribly knowledgeable Boniface.

  Not that it entirely mattered. “Had it… been possible to fight a campaign in Norway with a fair chance of winning… [Boniface] might have made all the difference,” a Hut 3 report concluded. As it was, the nominal agent’s information showed “the extent of the German strength” that Britain’s forces were inadequately fighting in the snowfields of Scandinavia.4

  GALEAZZO CIANO RETURNED to his office at the Foreign Ministry in Rome after a bad flu and met his father-in-law. “After ten days I found Mussolini more warlike and more pro-German than ever, but he says he will do nothing before the end of August, that is, after improvising preparations and after the harvest. Thus only three months remain to give us a ray of hope,” he scrawled in his notebook in late April.

  Ciano’s diary entries read like an excruciatingly slow-motion shot of a man hanging from the windowsill of a tall building, his fingertips slipping toward the edge. The American ambassador, William Phillips, came to the Duce with a message from President Roosevelt. It was “dressed in polite phrases,” but the gist was that if Italy entered on the German side, “some states that intend to remain neutral”—meaning America—“will need to revise their positions at once.”

  The warning only angered Mussolini, who wrote a “cutting and hostile reply” to Roosevelt. The news from Norway at the start of May that the Royal Navy had evacuated the British forces outside Trondheim, on the other hand, “literally exalts the Duce who, with ever-increasing emphasis, says he is certain of German victory.” Hitler wrote Mussolini a letter, in which he complained sardonically—as Ciano paraphrased him—“about the excessive speed of victory” in Norway, “which did not allow him to draw in the English forces more effectively to destroy them completely.”

  One bit of Rome gossip did make it into Ciano’s notes, but it could only add to his gloom. Luigi Barzini, a journalist for Corriere della sera who’d ghostwritten an autobiography of Mussolini, had been arrested. Ciano knew Barzini as one of the young and famous in Rome, like himself. It turned out that Barzini had told a British diplomat that Italy had agents inside Britain’s embassy, and also that “Mussolini is insane.”

  The incriminating evidence against Barzini came from “the usual documents we took” from the embassy, Ciano wrote. Manfredi Talamo and the P Squad were silently at work, and the keys to Britain’s embassy were still in their hands.5 The British embassy staff did nothing about Barzini’s warning.

  THE CHANGES IN Enigma messages showed up in the last days of April,
in all the keys but Yellow. Till then, German operators had encoded the starting position of their wheels twice at the beginning of their messages. At Hut 6, the method of using punched sheets to break the daily key depended on that pedantic repetition, and it was the only method that consistently worked.

  Now, in everything but Yellow, the operators were only encoding wheel positions once.

  “At one blow a catastrophe had fallen,” an internal account says. Yellow could still be read. But Red, the key of the German air force, was locked again. And really, no one knew how long Yellow would last. The entire Enigma project, all the work done till now, could crumble.6

  Like German merchant ships reporting to the army, the change in Enigma methods was an omen, an encoded message about the future. No one at Bletchley Park decrypted it.

  “THE WITHDRAWAL FROM southern Norway is not comparable to the withdrawal from Gallipoli,” Neville Chamberlain told the House of Commons. The prime minister had been putting this moment off; now he was trying to explain the failed campaign. He was right that the price of failure in Norway was less than the price of the disastrous attempt to take Constantinople during the Great War. Britain had committed far fewer troops to the landings near Trondheim. But then, one reason for that was Chamberlain’s long delay in preparing for war, which meant that Britain had fewer forces available, and France was a higher priority.

  Another difference from Gallipoli: Winston Churchill had borne the blame for that catastrophe, and it nearly ended his career. Churchill, once again first lord of the Admiralty, the cabinet minister responsible for the navy, had misread evidence of Germany’s intentions in Scandinavia. But the honorable members of the house aimed their fury at Chamberlain, who had misread the danger posed by Hitler for years.

  “I do not think that the people of this country yet realize the extent or the imminence of the threat which is impending against us,” Chamberlain said now, as if carrying on a dialogue with himself rather than the Commons.

  From the floor, someone shouted, “We said that five years ago.”7

  The next day, Chamberlain survived a no-confidence vote, but it was still a defeat: dozens of MPs from his own party voted against him or abstained. His time was over. The obvious replacement was the foreign secretary, Lord Halifax—who in a meeting with Chamberlain and Churchill turned down the job. He gave technical reasons, which would forever leave the question of whether he did not feel capable of the task, or perhaps did not want the blame for what he believed was coming.

  Churchill, the third man in the room, was quite willing.8

  The fall and rise of Winston Churchill deserves to be seen as it appeared at the moment. It was uncanny. The summer before, the American ambassador to Britain, Joseph Kennedy, relayed Chamberlain’s comment that Churchill was a “fine two-handed drinker and his judgment has never proved to be good.” Franklin Roosevelt’s emissary Sumner Welles met Churchill in his office in the winter of 1940 and reported, “When I was shown into his office, Mr. Churchill was sitting in front of the fire, smoking a 24-inch cigar and drinking whisky and soda. It was quite obvious that he had consumed a good many whiskies before I arrived.” Other American diplomats said that Churchill was old, tired, a has-been—showing that they were listening carefully to what Britain’s stuffy political class thought.9

  Churchill was sixty-five years old, indeed old by the standard of the time. He was habitually on the losing side of debates: he had opposed self-rule for India, opposed the abdication of King Edward, opposed cutting off Jewish immigration to Palestine—and opposed appeasing Hitler. He was stained by military failure, astoundingly combative, brutally witty, popular among the public, disliked by people who knew him, wildly imaginative, able to seize men and women’s emotions with his bursts of staccato sentences, and, most of all, ready to seize the hour when everyone else feared it. He’d fought without allies, been defeated, and was ready to claim his personal victory. Britain was now a battered country at war. Churchill shone with the confidence Britain needed.

  Churchill was burned out, insatiable, and suddenly young.

  It was May 9, 1940. The next day Chamberlain would go to the king and recommend that Churchill succeed him.

  “DEAREST LU,” ERWIN Rommel wrote to his wife that night, “We’re packing up at last… You’ll get all the news for the next few days from the papers. Don’t worry yourself. Everything will go all right.”10

  In the dark early hours of the next day, Rommel’s Seventh Panzer Division crossed the border from Germany into the Ardennes forest of southern Belgium. Rommel had a regiment with two hundred tanks under his command, as well as two regiments of infantry, an artillery regiment, and a varied list of other units. All this put Rommel, as division commander, just above the rank of anonymity. The division was part of a corps, the corps was part of an army, and the army was part of one of the three army groups that burst into the Low Countries on their way to France.

  Britain and France had expected Germany to attack through the open plains of Holland and northern Belgium. The Allies were ready to fling their own divisions northward, and did so as soon as the invasion began. What the Allies didn’t expect was for the main German attack to come through the Ardennes. It was impassable for an army, or so they believed. By taking the narrow roads of the forest, the Germans sliced into the weakest spot in the Allied defense. The plan depended on moving fast.

  Rommel moved very fast. On the third day, his division crossed the Meuse River. He was, by some accounts, at the very front of his troops, in the river, under fire, as they made the crossing. He pushed on with his tanks, leaving behind other German divisions on either side of him. At one point, he ignored a radioed order to halt by feigning that it never reached him. He reached the town of Avesnes, his assigned goal, and decided on his own to rush onward through the night with the first of his tanks to grab a bridge over the next river, the Sambre, at daybreak. On the far side of the river, the lead tanks ran low on fuel and had to stop. The rest of his division was strung out helter-skelter on the road, a long, terribly exposed finger stuck into the collapsing French defense. He drove back in a command car through French lines to collect his regiments and fight the way back to his stranded tanks.

  At the town of Arras, British tanks finally counterattacked his overstretched division. Rommel ran between his artillery and antitank positions to direct the defense. His aide-de-camp, alongside him, was shot and killed. His defense held. Rommel’s report said that he’d faced “hundreds” of enemy tanks.

  The actual number was less than ninety. An admiring account explains that the overstating of enemy strength is “a facet of every battle and every army.” A less admiring account notes that his reports also failed “to give credit to other formations which had contributed to his successes.”

  Rommel was a very modern general who “practically courted the attention of the photographic and film crews of the propaganda companies.” He built his own legend. He would win the Knight’s Cross, the highest Nazi military award, for taking the Sambre bridge. The propaganda writers of the German newspapers wrote about his “Ghost Division” that vanished and reappeared. The propagandists made Rommel the symbol of blitzkrieg. An artist assigned to his division painted a portrait of Rommel as the Aryan racial ideal, with “a high forehead, a strong, forceful nose, prominent cheekbones, a narrow mouth with tight lips and a chin of great determination.” Printed on postcards and posters, copies of Rommel’s portrait were churned out for German troops.11

  Yet Rommel’s report on Arras, with its exaggeration of British armored strength, added to his commanders’ fears that their tanks were advancing too quickly. A larger British and French counterattack would cut through their overstretched lines, they thought; they needed to rest, reorganize, and let supplies catch up with the tank brigades. Hitler ordered a halt.

  The pause lasted three days. In that time, the British Expeditionary Force retreated toward the small port of Dunkirk, set up defenses, and got ready for rescue by sea.12


  AT FOUR O’CLOCK on an afternoon in May, John Herivel showed up for his evening shift at Hut 6. Welchman was standing at the door, waiting for him. He had news: Someone else had filled in Herivel’s chart for him. That day it yielded results: among the three-letter indicators used by German Enigma operators, the chart showed a very clear cluster. As Herivel walked in, one of his colleagues was sitting at a table, working out the day’s settings for Red. After three months of disappointments, his idea was working splendidly.

  In past tense, it was easy to see that the Germans had changed the Enigma procedure at the end of April to tighten security before the invasion. When the huge operation began, the volume of messages increased drastically. One reason blitzkrieg worked was that the German air force worked tightly with the army. Orders, responses, reports went out constantly by wireless in the Red key. Enigma operators had to work faster. They had officers shouting at them. Some saved time by using the day’s ring settings as their first indicator. Herivel’s charts of the indicators showed where to look for the settings.

  Accounts of when the “Herivel tip” first succeeded are based on memories and give dates anywhere from May 11 to May 22. What matters is that after the first time, it kept producing results. Day after day, the tired overworked code clerks of the German air force unknowingly passed the day’s settings to the tired overworked men and women of Hut 6. In Hut 3, translators strained at messages garbled in the heat of battle and squeezed words out of them.13

  Denniston sent out a polite demand that no one try to save up the weekly day off to have enough for visits home. The strain of working continuously was too much. “You must have your rest day—you need it,” he wrote.14 In a step forward since the Norway campaign, the most important information from the German texts was now sent via MI6 to British army and air force headquarters in France. As in Norway, it made little difference in the face of military collapse.15