The Secret War: Spies, Codes and Guerrillas 1939–1945

Most of Bletchley’s staff displayed marvellous conscientiousness about secrecy, all the more remarkable among young men and women – Station X’s footsoldiers – performing humdrum functions. In 1941 a civilian doctor in Nottingham wrote to the GC&CS authorities, reporting that one of his patients, a Wren named Adele Moloney, was in bed with a high temperature, having overstayed her leave with symptoms of acute exhaustion. He wrote: ‘Miss Moloney has hypertrophy of the conscience to such an extent that she will not divulge the smallest detail of what she does, even though it is against her interests. As I find it difficult to believe that this young girl is on work which is so important that her doctor must have his hands tied by lack of knowledge, I thought I would write to ask for your comments.’ Bletchley responded blandly that ‘there is in the ordinary way nothing that we know of in the work that she does that is in any way likely to be prejudicial to her health. The same work is done by a large number of other girls, none of whom so far as we know have suffered in any way.’ But BP told the doctor that Miss Moloney’s discretion was not merely correct, but ‘highly commendable’, and so indeed it was.

There was much unease among the administrators about the security risk posed by the rolling population of cooks, cleaners and workmen who serviced Station X. A 1941 report reflected uneasily: ‘New faces are being sent daily from the Labour Exchange to Bletchley Park.’ A series of flagrant breaches in the spring of 1942 prompted a magisterial memorandum to all personnel from the Park’s senior security officer: ‘There have been recent instances among you of a spirit of such reckless disregard for the consequences of indiscretion as would seem to argue not only a condition of ignorance or folly, but a contempt for the laws by which each one of us knows himself to be bound. In one instance [a BP staffer] disclosed the nature of their duties within her family circle … [this] was repeated by one of its members in mixed company, actually at a cocktail party, whence it was duly reported to me. In another instance one of the most vital tasks in which the organisation is engaged was disclosed, possibly in a spirit of pride or ostentation, in an after-dinner conversation to the Seniors of this person’s old College, whence a report reached me … It would be a reflection on your intelligence to suppose that you do not realise … that an idle piece of boasting or gossip … may be passed to the enemy and cause, not only the breakdown of our successful efforts here, but the sacrifice of the lives of our sailors, soldiers and airmen, perhaps your own brothers, and may even prejudice our ultimate hopes of victory.’

If this broadside was fiercely worded, it was not in the smallest degree extravagant. Bletchley Park was the jewel in the crown of Britain’s war effort, one of its principal assets in the struggle to save the nation from Nazi enslavement. Alan Brooke wrote in his diary after visiting GC&CS in April 1942: ‘A wonderful set of professors and genii! I marvel at the work they succeed in doing.’ Betrayal of its secrets could overnight have crippled the cause of freedom – most immediately by denying to the Royal Navy its key to the locations of Dönitz’s U-boats. Well before the Soviet Union became a supposed ally in June 1941, British traitors were passing to NKVD agents whatever pearls of Ultra they thought might be of interest to Moscow; it was fortunate that Stalin did not inform Hitler of Bletchley’s doings – in the months before ‘Barbarossa’, he was desperate to appease Berlin.

It was an even larger stroke of fortune that Germany’s commanders sustained their dogged belief in Enigma’s inviolability. Early in the 1930s the head cryptanalyst of Göring’s Forschungsamt cipher unit, Dr Georg Schröder, asserted passionately: ‘the whole Enigma is garbage!’ No heed was taken of his warning, which was deemed only relevant to the commercial machine, which lacked a plugboard. In October 1939 Lt. Col. Ruzek, former head of Czech cryptanalysis, revealed to German interrogators that the Poles had been working with the French to break Enigma traffic. In captured Polish files, the Nazis discovered three 1938 plain-language translations of signals from a German cruiser in Spanish waters. Polish PoWs were exhaustively interrogated in attempts to discover how these messages had been decrypted, but the Abwehr drew a blank: almost all the men who knew the answers were at that time beyond their reach. OKW/Chi’s cryptanalysts in Berlin felt intensely frustrated that, while they were supposedly responsible for ensuring the security of the Wehrmacht’s communications, they were expressly forbidden to conduct tests on breaking Enigma traffic. They nonetheless believed the system institutionally safe, and argued that occasional signals could only be broken if dispatched by careless operators who neglected procedure. Even in 1946 the Wehrmacht’s chief cryptanalyst, Wilhelm Fenner, maintained stubbornly: ‘The Enigma was regarded as antiquated, but it was secure when properly used.’

It is possible to identify several moments of the war at which British blunders could have enabled the Germans to recognise that their ciphers were compromised, and plug the gusher of intelligence flowing from Bletchley Park. On 24 August 1941, Churchill made a BBC broadcast in which he alluded to explicit numbers of Jews known to have been murdered by the SS behind the Eastern Front. The Germans noticed, and within days Oberstgruppenführer Kurt Daluege issued an order that details of such killings should no longer be mentioned in radio traffic: ‘The danger of enemy decryption of wireless messages is great. For this reason only non-sensitive information should be transmitted.’ One consequence of Churchill’s slip was that when in October 1942 the Foreign Office compiled a report on known German atrocities, especially those committed against Jews, this was not publicly released, to avoid any new risk of compromising intelligence sources.

It was remarkable that the German high command failed to draw far-reaching conclusions from Churchill’s August 1941 words, and likewise a year later when German interrogation of Allied prisoners revealed that Montgomery’s Eighth Army had been expecting the Afrika Korps’ attack at Alam Halfa in North Africa. Early in 1942 also, Dönitz became acutely suspicious that the Allies were monitoring his communications with U-boats. He was persuaded that his fears were groundless by British carelessness with their own convoy codes, which were being broken by the Kriegsmarine’s decryption service, the B-Dienst. If Enigma was indeed insecure, the admiral reasoned, the British would have learned about this yawning chasm in their own security: a nation clever enough to crack U-boat signals would employ better codes of its own. The U-boat chief was careful enough to introduce the four-rotor Enigma, but insufficiently so to question the fundamental basis of the system.

Potentially the most dangerous threat to the Ultra secret also came in 1942. On 5 May the Australian freighter Nankin sailed from Fremantle for Calcutta with a cargo of explosives, 180 crew and 162 passengers. In the Indian Ocean early on the morning of 10 May, a small floatplane circled the ship. Soon afterwards its parent, the German raiding cruiser Thor, closed in and opened fire. Nankin signalled ‘Raider sighted,’ and her captain jettisoned the confidential books before surrendering an hour after the first shot. The passengers and crew were transferred to Thor and its accompanying supply ship, along with hundreds of sacks of mail. Among these, the Germans identified a consignment from the Combined Operations Intelligence Centre at Wellington, New Zealand. Its contents included a ‘Most Secret’ summary for the period 21 March to 20 April, largely based on Ultra material, which gave the positions of every known Allied and enemy warship and merchant vessel in the Pacific and Indian Oceans. With criminal carelessness, these documents had been dispatched not by hand of Nankin’s captain, but instead with the general mail.

Even though the COIC data was well out of real time, imaginative analysis of the intelligence summary by the Abwehr would have shown the Germans that some at least of their ciphers, as well as those of the Japanese, were compromised. Such scrutiny appears never to have taken place. The Thor’s captain saw no special urgency about sending the captured documents to Berlin. Only at the end of July, after the raiding cruiser’s supply ship docked at Yokohama, did Germany’s naval attaché in Tokyo receive the COIC papers. A further month elapsed before Berlin authorised him to pass the documents to its Asian ally. Thereafter, the Japanese navy changed its main code, so that the US Navy lacked ‘real time’ decrypts to empower its operations during the 11–12 October Battle of Cape Esperance, the 26 October Battle of Santa Cruz, and the 13–15 November Guadalcanal actions.

It would be fanciful to suggest that the Nankin captures thus altered the course of the naval war, because the code alteration was part of a regular routine: the Japanese still doggedly refused to acknowledge that their entire communications system was vulnerable. But if they had read the Allied COIC documents soon after the Germans got their hands on them, and had possessed a more sophisticated capability for assessing intelligence, they would have changed their ciphers weeks, instead of days, before launching their June assault on Midway, with momentous consequences. The British do not appear to have told the Americans about the Nankin loss. This may have been because they suffered an attack of well-deserved embarrassment about a major breach of security. It was the same story when the second of two copies of the Japanese Purple cipher machine, presented to the British by their American creators, was dispatched to the Ultra team in Singapore by freighter. It is known to have left Durban in December 1941, but thereafter vanished without trace, its fate unknown from that day to this.

No Whitehall correspondence concerning the Nankin has thus far been found in British archives, and it would be unjustified to build too high a tower of speculation around its story. The Allies escaped significant consequences from their blunder – and from the others cited above – because the intelligence systems of Germany and Japan lacked the coherence and imagination to profit as they should have done from their haul of Allied secrets. One further critically dangerous moment should be mentioned: in November 1942 the Germans swept across unoccupied France. Among those whom they took into custody in Vichy were three Poles who had served in Gustave Bertrand’s codebreaking department since 1940, and before that had been engaged in Poland’s own cryptographic operation. In March 1943, two such prisoners were interrogated by German sigint experts in the presence of an Abwehr officer. Had the men told what they knew, or could have surmised, about the Allies’ progress in cracking Enigma, the worst could have happened. Fortunately, before being questioned the Poles were briefly alone together, and coordinated explanations which were accepted: that while some traffic had been briefly broken in 1938, improved German systems thereafter closed the breach. Here were two more people to whom the Allies owed a debt for their role preserving the Ultra secret. Cleverer men in Berlin and Tokyo might have made much of the material and prisoners that fell into their hands, and abruptly halted the music for the Allies’ wondrous dance across the ether.

2 FLIRTING WITH AMERICA

From the day Winston Churchill became prime minister until Pearl Harbor nineteen months later, his foremost political purpose was to drag the United States into the war, because only thus could the embattled island hope to accomplish more than its own survival. To that end, the British sought the closest cooperation the Americans would countenance. They professed to wish to extend this to intelligence, but in truth sought a notably one-sided relationship, which protected most of Britain’s secrets. In the spring of 1940, Stewart Menzies asked the Canadian businessman Sir William Stephenson to try to open a link to J. Edgar Hoover, director of the FBI. Stephenson, eager for a top-table role for himself, set about this mission with a will, using an unlikely mutual acquaintance, the former world heavyweight boxing champion Gene Tunney, with whom he had sparred in France back in 1918. In those days the Canadian had been a fighter pilot, who went on to make a fortune before creating his own industrial intelligence network in the 1930s, from which he offered material to the British government. This opened a relationship with Desmond Morton and Dick Ellis of Broadway, which continued after the outbreak of war. Hoover, before meeting the ebullient Canadian, took care to secure White House approval. Stephenson reported back to London that the FBI chief was keen to cooperate with MI6, and had suggested that his visitor should secure some official title to formalise his status in the US.

Menzies promptly gave Stephenson a modest cover role as Passport Control Officer in New York, where he set up shop on 21 June 1940. Thereafter the Canadian built a substantial organisation which in January 1941 acquired the title of British Security Coordination. BSC, quartered on the 35th and 36th floors of the Rockefeller Center on Fifth Avenue, was charged with sabotaging Axis operations, liaising with the Americans and gathering intelligence about enemy activity. It also managed anti-Axis propaganda throughout the Americas. In its role as a flag-carrier for Britain and its spies, it enjoyed considerable success until the respective national intelligence services began to bypass BSC in favour of doing business with each other direct, in the spring of 1942 after the US came into the war.

New York became MI6’s most important out-station, from which its agents set forth to try to penetrate Axis-run companies and foreign embassies. BSC could claim credit for such coups as tipping off the FBI in November 1940, when a Mexico City informant revealed that four German ships intended to run the British blockade across the Gulf of Mexico: the US Navy stopped the ships. Likewise, J. Edgar Hoover warned BSC that the Italians intended to transfer to South America almost $4 million in cash, which might be used to bankroll sabotage. Two-thirds of the money got through, but a BSC agent alerted police in Mexico City about the smuggling operation: they opened the bags and confiscated $1.4 million. On the debit side, however, Stephenson was alleged to have recruited some frankly disreputable officers. Guy Liddell of MI5 fumed about one in particular, Ingram Fraser, who was alleged to have been ‘running a mistress in Washington DC who was supposed to be acting as an agent on the Finns. She was getting $500 a month for her flat and $500 for her services, all paid out of office funds.’ BSC wasted as much energy on absurdities as every other intelligence organisation: three of its cleverest officers – Oxford dons Freddie Ayer, Bill Deakin and Gilbert Hignet – spent weeks planning a response to a possible Japanese invasion of South America.

What mattered most, however, was Stephenson’s liaison role: he forged close personal relations with many prominent administration figures, and especially with Colonel William Donovan, who would become the most influential single personality in America’s wartime foreign intelligence operations. Donovan was a natural showman, where the other belligerents’ spymasters were men of the shadows or – in the case of Stalin’s intelligence chiefs – creatures of the night. Born in 1883, ‘Wild Bill’ rose from a poor Irish background in upstate New York to become a classmate of Franklin Roosevelt at Columbia Law School; he later became an influential friend of the president. He fought with Pershing against Pancho Villa, then commanded the New York Irish 69th Regiment on the Western Front in 1917–18, returning home as his nation’s most decorated soldier, a colonel with the Medal of Honor and a reasonably authentic reputation as a hero. Thereafter he fulfilled several fact-finding missions for the White House. Following the first of these, to the new Soviet Union in 1919, Donovan urged Washington against supporting White Russia, describing workers in Siberia as ‘yearning for Bolshevism’. As US Attorney for the Western District of New York, he became famous – or notorious – for his energetic enforcement of Prohibition. Later, though himself a Republican, he visited Abyssinia and Spain as an emissary for Roosevelt the Democrat. He returned home an implacable foe of Hitler, and advocate of US engagement in Europe.

In 1940 and 1941, Donovan made trips to London during which Stephenson ensured that he received red-carpet treatment, including lunch with the prime minister. Some British officers recoiled from the visitor’s brashness. Maj. Gen. John Kennedy, director of military operations, wrote in his diary: ‘Donovan … is extremely friendly to us & a shrewd and pleasant fellow and good talker. But I could not but feel that this fat & prosperous lawyer, a citizen of a country not in the war … possessed very great assurance to be able to lay down the law so glibly about what we and other threatened nations should & sh[oul]d not do.’

Donovan’s influence at the White House nonetheless ensured continuing British gratitude and goodwill. In September 1940 he persuaded Roosevelt to commit the US to a policy of intelligence collaboration with Churchill’s nation. When Godfrey, the director of naval intelligence, visited the US in May 1941 with his personal assistant Commander Ian Fleming, in New York the two men stayed at Donovan’s apartment. The admiral’s trip was not an unqualified success: he was shocked by the depth of hostility between the US Army and US Navy, and got little change out of Hoover, who was less interested in joining the war against the Axis than in securing the FBI’s monopoly control of the nation’s intelligence activities. In this, Hoover was unsuccessful. While his Bureau retained responsibility for counter-espionage – the role of MI5 in Britain – Godfrey and Stephenson played some part in convincing the Roosevelt administration that the country needed a new intelligence organisation, and that Donovan was the man to run it. From July 1941 he held the title of Coordinator of Information, though in reality his new Office of War Information was an embryo secret service, and he set about supervising its birth and precocious growth with energy and exuberance.

Donovan and Stephenson – the latter known in the US as ‘Little Bill’ rather than ‘Intrepid’, which was merely his telegraphic address – were buccaneers both, who shared credit for securing a reasonably free hand for British intelligence operations in the Americas, against the wishes of the FBI and the State Department. Their rapport did not, however, change an overarching reality: the wartime relationship between Britain and the United States was characterised by tensions and suspicions, merely painted over by the magnificent rhetoric of Churchill and Roosevelt. In 1940–41 the British were fighting for their lives while Americans were not, and indeed operated a cash-and-carry policy for the modest quota of weapons and supplies they sold to Churchill’s people. Most of America’s defence community had some respect for Britain, but little affection.

The British officers privy to the Ultra secret knew that they were custodians of one of their country’s most precious assets, which would become instantly forfeit if any hint of their growing successes reached Berlin. American security was poor, as might be expected of a people not yet committed to the struggle, who were anyway constitutionally ill-suited to keeping secrets. British intelligence chiefs were eager for American goodwill, but doubtful how much of practical value their US counterparts could tell them. Pending evidence that a two-way traffic could benefit their embattled island, they determined to give away as little as possible. Moreover, as an anguished Whitehall hand scribbled during the 1941 debate about how much to tell a visiting US delegation: ‘What will they think if they find we have been reading their own stuff?’ – a mild embarrassment about which Churchill came clean to Roosevelt on 25 February 1942, with the assurance that decryption of US material had stopped immediately after Pearl Harbor.

The sparse 1940–41 meetings and exchanges between the two nation’s codebreakers and intelligence officers took place in a climate of mutual wariness, and it was the Americans who displayed greater frankness. On 31 August 1940 the British were told that the Signals Intelligence Service had broken the Japanese Purple key. This revelation prompted no immediate invitation to Bletchley: when the Tizard mission visited the US in September to show off such revolutionary technology as the cavity magnetron – a tempting morsel, key to new-age tactical radar, and intended to promote American reciprocity – information about Ultra was explicitly excluded. On the American side, Laurance Safford of the US Navy’s Op-20-G codebreaking team was likewise opposed to sharing its secrets with the British. In December 1940 the two nations reached an agreement to pool information about codebreaking, but both were slow to bring this into effect. Only on Japanese material was there immediate close collaboration: in February 1941 the British cryptanalysis team in Singapore and its American counterpart in the Philippines exchanged liaison officers, who discovered that both were in about the same place with Tokyo’s codes. In the early war years the British did better than the Americans in monitoring some low-level Japanese armed forces traffic, though they failed to break into their higher ciphers. Nonetheless, when British forces in 1941 requested urgent American assistance in securing high-altitude photographs of Japan’s naval bases, Washington vetoed the proposal.

At the height of the Luftwaffe Blitz on Britain two FBI agents, Hugh Clegg and Clarence Hince, visited London to study ‘law enforcement in time of war’. Guy Liddell of MI5 thought that while the visitors looked somewhat thuggish, Clegg seemed ‘a very good fellow’. Such warmth was not reciprocated. On their return, the two men delivered to Hoover a report depicting the British, explicitly MI5 and the Metropolitan Police, in terms of withering scorn. They complained that it was difficult to arrange meetings before 10 a.m. or after 4 p.m. because ‘the transport situation is very difficult, you know’. They said that ‘The fact “exploratory luncheons” were usually two hours in length made our working day rather limited, particularly when compared to the customary hours that officials of the FBI are engaged in official business.’ They concluded that the British ‘might win the war if they find it convenient’. This report set the tone for the FBI’s view of the British for decades thereafter.

In January 1941, when an American codebreaking team – two army, two navy – paid a pioneering visit to Britain, they brought with them a remarkably generous gift: a mimicked Purple machine, of which a second copy was handed over later. The British, however, reciprocated cautiously. With Winston Churchill’s explicit sanction they admitted the visitors to Bletchley, and explained the Hut system. They revealed the bombes, GC&CS’s most critical innovation, but thereafter prevaricated about fulfilling American requests to be given an example of what Washington described as ‘a cypher-solving machine’. There were very good reasons for this – the US was not in the war, and the bombes were scarce pearls. The Americans recognised that they had seen in action a system way ahead of anything the US armed forces were doing. Alfred McCormack, who became the secretary for war’s special assistant on comint, said later of Bletchley: ‘It’s not good – it’s superb.’

Some people in Washington, however, were irked by apparent British pusillanimity. They themselves made little serious headway in reading Enigma traffic until floodgates opened in 1943, and – in the words of an exasperated British officer – ‘showed no appreciation of the extent of the problems facing Bletchley Park and Britain’. The Park’s Washington representative, Captain Edward Hastings, reported in November 1941 that ‘there is grave unrest and dissatisfaction about free exchange of special intelligence’. Some Americans were doggedly convinced that the British were holding out on them. As late as December 1942, when Alan Turing visited the US, he was denied admission to the Bell Laboratories in revenge for alleged British foot-dragging about collaboration, and was finally allowed inside only after a huge and protracted transatlantic row. Although William Friedman later forged warm personal relations with BP’s senior personnel, he himself made his first visit to Britain only in May 1943, about the time a formal and indeed historic intelligence-sharing pact was agreed between the two nations. Meanwhile collaboration remained wary and incomplete. Even after Pearl Harbor, Bletchley and its owners remained fearful not only about American security shortcomings, but also about the danger that this brightest jewel in the imperial crown might somehow be snatched from them by the boundlessly rich, irresistibly dominant new partner in the Grand Alliance. Alastair Denniston wrote that for Britain Ultra was ‘almost lifeblood’, whereas the Americans seemed to view Enigma, with the detachment of distance and freedom from mortal peril, merely as ‘a new and very interesting problem’.