GCHQ

Churchill eventually wrote to Roosevelt and owned up to British work on American diplomatic codes. ‘From the moment we became allies,’ he explained, ‘I gave instructions that this work should cease. However, danger of our enemies having achieved a measure of success cannot, I am advised, be dismissed.’ In fact, it is unlikely that all work on American traffic ceased. In areas such as the Middle East, Britain had a considerable incentive to continue to work on American commercial traffic, much of which was in commercial code or plain text. Indeed, a close reading of Churchill’s assurance to Roosevelt suggests that it might have related to diplomatic traffic only.

 Some GC&CS staff recall work on the traffic of American commercial attachés throughout the war, although as yet no documents have been released.

 Predictably, clear traffic from American oil companies was being intercepted in 1944 as they began to look for new markets in Europe.

For this very reason, the US Army and Navy were agreed that nothing should be passed to the British about American code-making procedures, such as the Sigaba cypher machine. General George Marshall, the US Army Chief of Staff, specifically forbade any such exchange in September 1940.

 Anxiety about protecting national cypher systems persisted through the war on both sides of the Atlantic. In February 1945 Britain’s newly formed Cypher Policy Board debated a proposal by its Secretary, Captain Edmund Wilson, for ‘free and complete interchange’ with the Americans on cypher machine development, together with scrambler phones and secure speech.

 This horrified both Edward Bridges, the Cabinet Secretary, and Sir Stewart Menzies, Chief of SIS, and the idea was rejected. Cooperation on communications security would focus on machines specially designed for combined use.

The gradual collapse of the British monopoly over Ultra intelligence paved the way for closer Anglo–American sigint cooperation. As we have seen, Bletchley’s initial idea for wartime cooperation was that the Americans would continue their pre-war focus on Japanese traffic; meanwhile the British would handle the work on Enigma, dispensing its product to the Americans as they saw fit. Although they had informed the Americans about Enigma in 1941, some precise details of processing had been withheld. Bletchley was determined to prevent the Americans working on Enigma in parallel, even though the Battle of the Atlantic gave Washington a legitimate need for Ultra intelligence. However, once the German Navy introduced an improved Enigma machine with four rotors, the British could not produce enough ‘bombes’ to deal with the increased number of tests required to break it.

 In September 1942, Joseph Wenger, who led the US Navy code-breakers, proposed spending $2 million to acquire no fewer than 230 four-wheel ‘bombes’. This was ten times the number available to Bletchley. John Tiltman, Britain’s Soviet code specialist, realised that American sigint was beginning to operate on an industrial scale, and that for Bletchley Park the game of ‘Ultra monopoly’ was surely up.

In September 1942, Edward Travis and the head of Bletchley Park’s Naval Section, Frank Birch, travelled to Washington and concluded the ‘Holden Agreement’, which established full and integrated collaboration on German naval traffic, including Enigma. This was a key part of the emerging Anglo–American sigint relationship, and a constituent part of the secret alliance which still exists to this day.

 Travis’s hand was strengthened by the remarkable fact that the US Navy breathed not a word about the Holden Agreement to the US Army. The British therefore persisted in their hopes of keeping control over the processing of Ultra material derived from Luftwaffe and German Army traffic. Nigel de Grey, the Deputy Director of Bletchley Park, was apoplectic at the possibility of the Americans being allowed to duplicate further British work on Enigma. However, a US Army code-breaker based at Bletchley, Colonel Telford Taylor, suggested a tactful way forward. He advised his superiors in Washington that all they needed for the time being was a small ‘foothold’ in the work on Enigma, which would allow them to gain experience. More level-headed organisational types at Bletchley Park, such as Gordon Welchman, could see that the ability of the Americans to procure unlimited numbers of bombes was crucial, adding, ‘We certainly need help.’

 The result was the BRUSA agreement, a further crucial landmark in the construction of the Anglo–American sigint relationship. On 17 May 1943, Bletchley agreed to American participation in work on German Army and Air Force traffic. A second Holden Agreement on naval sigint followed in 1944. These treaties were of enormous importance, and paved the way for more ambitious post-war sigint alliances.

The exigencies of war had broken Britain’s cryptographic monopoly on Ultra. However, Ultra was a military system, representing the core work of Bletchley Park. There is no evidence that Britain and the United States concluded an overarching treaty on diplomatic or commercial sigint, the material that GC&CS worked on at Berkeley Street. In 1942, Alastair Denniston, who had been moved sideways to manage diplomatic sigint, arranged for cooperation on a number of specific countries such as Italy, France, Spain, Portugal, Japan and, of course, Germany. However, this was done on an ad hoc basis. There was no diplomatic BRUSA agreement. It seems that the Americans were not intercepting and working on a range of materials that would have prompted a wider deal. Typically, Denniston told John Tiltman, with evident relief, ‘They do no work on any of the Near Eastern governments.’

Denniston’s main point of contact in the United States was William Friedman and the US Army code-breakers, who dominated American work on diplomatic systems. The Americans were keen to cooperate, since up until 1941 the US Army had been intensely focused on the diplomatic cyphers of Japan. In 1940 the Americans lost access to Japan’s diplomatic cypher, and it was only recovered as the result of a prodigious effort by a team under Frank Rowlett. By contrast, British code-breakers were working on the diplomatic cyphers of some twenty-six different countries.

 Therefore, when the Americans offered access to ‘Magic’, the British reciprocated with a wide range of diplomatic material, including high-grade Italian systems. Then, in March 1942, John Tiltman visited Washington and brought with him Spanish and Vichy French cyphers. Given the arrival of American forces in the Mediterranean, this was valuable material. By 1944 the Americans had received more material from the British on diplomatic cyphers used by the Greeks, Hungarians, Iranians and Iraqis. However, the processing went on behind a curtain. Denniston asked at one point, ‘Do they actually work on the stuff which we send them, or do they simply put it in their library?’ Diplomatic cyphers from countries that the British considered to be client states, such as Egypt, were withheld.

Sharing diplomatic product caused some embarrassing problems. Foreign diplomats in London or Washington often reported their conversations with British officials in the messages they sent home. The British sometimes did not want the Americans to ‘listen in’ on these conversations, since they might involve ‘disparaging remarks about American policy or officials’. Therefore, they developed a special reserved series called ‘Res’, that contained material that was not to be given to the Americans. This was not an effective solution, because, as Alexander Cadogan, the senior official at the Foreign Office, explained to Stewart Menzies, the Americans would often obtain and break some of the same traffic themselves, and so would ‘become suspicious’. By the spring of 1944 the Americans clearly knew about ‘Res’, and pressed the British to abandon the practice. However, Cadogan refused, since the war was drawing to an end, and the antagonistic politics of post-war settlements were looming.

The Americans nurtured their own anxieties. Would Anglo–American sigint cooperation continue after the war? As early as 1942, Colonel Alfred McCormack, one of the more important visitors to Bletchley, warned his superiors in Washington that the British were ‘very realistic people’, and so would ‘certainly at some time – possibly while the war is still on – resume work on United States communications’.

 However, continued convergence of Anglo–American sigint was ensured by early fears of the Soviet Union, which were visible as early as 1942. Senior officers on both sides of the Atlantic, including Field Marshal Lord Alanbrooke and General Douglas MacArthur, were of one mind on the ‘Russia problem’. On 31 July 1942, Geoffrey Stevens, a code-breaker from GC&CS, went out to Arlington Hall, the US Army’s code-breakers’ centre in Washington. One of the subjects he discussed there was the Soviet Union, and he was fascinated to learn that the Americans were intercepting all the Soviet traffic in and out of Washington. They were also collecting Soviet traffic elsewhere, for example between Moscow and the Soviet Embassy in Tokyo. He reported that the Americans ‘do nothing about it at the moment’ by way of decryption, since they were so pressed for code-breaking capacity against the Axis. However, sooner or later, he added, ‘They will inevitably try and break this since they do not trust the Soviets further than they could throw a steam-roller.’

 Much as Stevens predicted, the Americans began a Soviet Group in February 1943. Meanwhile, the British moved their own existing Soviet team from Ryder Street in London to larger premises at Sloane Square in late 1944.

 Although the two allies were still working in isolation on the ‘Russia problem’, the foundation of future collaboration was already emerging.

Anxiety about the Soviet Union increased markedly during early 1944. By April the Red Army was pushing into eastern Hungary, and this filled Moscow with a newfound confidence. Stalin’s determination to impose a Communist government on Poland was already evident, and pointed to future trouble. Some British diplomats in the Foreign Office remained hopeful about the possibility of post-war cooperation with the Soviet Union, but their military colleagues did not share their optimism. Indeed, the main future strategic planning body in Whitehall, the Post Hostilities Planning Committee, which was shared between the diplomats and the military, tore itself apart over this issue. The Foreign Secretary Anthony Eden had to step in in late 1944, and banned the further circulation of its papers. One staff officer lamented that there were to be ‘no more games of Russian scandal’. Russia was now a forbidden subject, and between late 1944 and early 1946 Britain’s main body of intelligence analysts, the Joint Intelligence Committee (JIC), did everything it could to avoid discussing the dreaded subject of the Soviet Union.

Accordingly, it was only in June 1945 that the American code-breakers formally proposed to the British that they cooperate against the Soviet Union, giving the overall programme the code name ‘Bourbon’. The formal Anglo–American collaboration on the wider ‘Russian problem’ was so incredibly secret that it was not written down, and amounted to a simple handshake between Group Captain Eric Jones, the British sigint liaison officer in Washington, and a senior American naval officer in June 1945. Meanwhile, all eyes were on the Allied reoccupation of Europe and the remarkable sigint prizes that were even now being recovered from the smouldering ruins of the Third Reich.

3

Every War Must Have an End

On 26th August one of the operators from Army Group, South Ukraine … suddenly broke into violent remarks about Hitler, using the peculiarly foul language in which the Germans delight. The operator at Supreme Army Command tried to shut him up in equally filthy language. This interchange lasted for about ten minutes …

The incident is only noteworthy as a possible indication of the way things are going.

Nigel de Grey, Deputy Director at Bletchley Park, to Sir Stewart Menzies, 14 September 1944

By the autumn of 1944 the Second World War was ending and the Cold War had, to all intents and purposes, already begun. In the east, the German Army was collapsing fast, and by September Soviet forces were at the borders of Prussia. A month later, American forces had entered Germany from the west, capturing the ancient town of Aachen. While much bitter fighting lay ahead, the minds of officials in London, Washington and Moscow were increasingly focused on the post-war settlement. Wartime relations with Russia had never been easy. Stalin’s intense and unwavering suspicion was underlined by the fact that, throughout the war, he had refused to leave Soviet-controlled territory to meet Churchill and Roosevelt. Harsh Soviet behaviour in newly occupied areas like Poland already pointed to post-war confrontation and rivalry, and all eyes were on the advance into Germany.

Britain and the United States were gearing up for piratical raids on the headquarters and laboratories of a collapsing Third Reich, and Axis sigint material was the treasure that was most actively sought. A joint Anglo–American planning group began consulting with Bletchley Park about what material it wished to scoop from an occupied Germany. By early 1945, Intelligence Assault Units were moving into Germany alongside the fighting elements of Allied formations, looking for all kinds of top-secret German experimental weapons. Bletchley Park despatched its own Target Intelligence Committee teams, known as ‘TICOM teams’, made up of a mixture of British and American personnel, to seek out cryptographic equipment and sigint personnel from Germany. The whole TICOM programme was run on what Commander Edward Travis called ‘an entirely inter-allied’ basis.

Suddenly, boffins in glasses and cardigans found themselves turned into amateur commandos. Whisked away to a quarry near Bletchley, those selected for this task were given a short course in the use of sub-machine guns and hand grenades. They began on the Thompson sub-machine gun, but soon found the lighter Sten gun to be an easier weapon to handle. None of them performed well, but nevertheless they were soon on their way to Hitler’s ‘Alpine Lair’ at Berchtesgaden. Major Edward Rushworth, one of the senior British officers from Hut Three, led a TICOM team of a dozen officers, accompanied by Selmer Norland, an American stationed at Bletchley Park. They arrived at the major German headquarters at Augsburg on 8 May, VE-Day. Augsburg had been home to the famous German ‘Fish’, or Geheimschreiber, the encyphered teleprinter which Bletchley had eventually defeated with the mighty ‘Colossus’ computer. Sadly, all these beautiful machines, lovingly manufactured by Lorenz, had been smashed and the cypher wheels had gone. The dejected team surveyed the debris. However, a day later their spirits rebounded when they gleefully recovered a single intact late-model ‘Fish’ from a town on the Austrian border.

On 12 May 1945 they reached Hitler’s Alpine retreat. The Führer’s accommodation had been heavily bombed, but a hundred feet below ground was a maze of bunkers and tunnels to explore, including an emergency power station and a complete telephone exchange. No more cypher machines seemed to be in evidence, and the mission was tailing off when, as a last task, Rushworth set off for nearby Rosenheim on the Austrian border, to question a cryptographer who had been working for the German High Command (OKW). While they were there, a group of other German prisoners sent a message asking to speak to the ‘proper people’. This team had served in the OKW headquarters sigint units and now revealed that, terrified of the rapid Soviet advance, they had buried their equipment under the pavement in front of their headquarters. Called ‘OKW-Chi’, they had successfully broken what was referred to as ‘Russian Fish’. This was an encrypted Soviet military teleprinter that achieved an early version of packet switching, breaking each message into nine different parts and routing it along separate channels, before reassembling it. The Germans had already worked out that their code-breaking triumph would have post-war value, and hoped to sell themselves on as a complete team.

They were not disappointed. By 23 May they had been encouraged to unearth and set up their equipment, allowing them to resume decrypting Soviet command traffic. The Bletchley team were in awe of this vast technical display, which was eventually packaged up again in over a hundred boxes and chests. The eight tons of equipment and the complete German staff were loaded onto five lorries, which then wound their way slowly through a devastated Germany towards Bletchley. They arrived on 6 June 1945, and the equipment was set up and tested at the nearby radio station of Wavendon Manor.

 The German team was later employed intercepting Soviet encyphered teleprinter traffic which the British code-named ‘Caviar’, and although the messages were mostly about administration rather than policy or strategy, they provided rare insights into the daily activities of Soviet armed forces in post-war Europe.

 More treasures followed, and ultimately a further five tons of documents pertaining to Soviet codes and cyphers would arrive. In mid-June, Edward Travis asked Russell Dudley-Smith, a senior Bletchley Park officer, to try to establish some priority in exploiting the mountain of material now pouring in, but little did they know that they would still be working on this material in 1951.

 One-of-a-kind equipment stayed in Britain, while any duplicates were shipped to America.

Yet another important haul was brought in by Colonel Paul Neff, an American who headed TICOM Team 6. This group included William Bundy, later US Assistant Secretary of State under President Lyndon B. Johnson, and Geoffrey Stevens from Bletchley Park. In April 1945 they pushed into southern Germany at Magdeburg, near Leipzig, and took control of a castle at Burgscheidungen which had recently been the headquarters of a code-breaking unit of the German Foreign Ministry called the Balkanabteilung, whose tasks had largely focused on Soviet and Balkan traffic. The fourteen staff and their documents were flown to Britain and taken to Bletchley Park. Burgscheidungen was in an area that would later be designated as part of the Soviet Zone, so Neff destroyed all traces of the German code-breakers’ presence before departing.

The British caught Generalmajor Klemme, the Senior Commander of Radio Intelligence for the Luftwaffe, at the Husum-Milstedt intercept station on 19 May 1945. At first he was taken to Neumuenster Prison, but from there he was brought to Britain, and worked with the Allies on sigint in Germany until 10 March 1948, when he was considered to have been drained of all he knew about Soviet communications. On 1 May 1945, Major Oeljeschaeger and Major Beulmann from the Berlin Cryptographic Centre, which had been based in a stable block of the Marstall-Neues Palais at Potsdam, had fled in the direction of Hitler’s complex at Berchtesgaden. A few days later, with the Allies closing in, they stopped at Viehoff to burn all the records of Branch 3, and they fell into Allied hands on 22 May near Munich. On 5 July they were flown to Britain and placed in a special camp. They were surprised to be welcomed by their Branch Chief, Lt Colonel Friedrich, who had been captured before them. By June 1945 the British and Americans had scooped up most of the senior Luftwaffe sigint officers whose traffic they had listened to assiduously for much of the war.

The TICOM teams were competing with the Soviets, who were also swooping on German cryptographic assets. To their surprise, Bletchley Park discovered that the Soviets had taken over some German Enigma-based communications nets and Fish teleprinters, and had begun using them for their own purposes. However, initial hopes of a post-war dividend from the breaking of these machines were quickly dashed. Roy Jenkins, who was then working at Bletchley Park, recalls this odd interlude in May 1945:

When the Russians got to Berlin they took over the Fish machines in the War Ministry, somewhat changed the settings, and proceeded to use them for sending signals traffic to Belgrade and other capitals in their new empire. We continued to do the intercepts and played around with trying to break the messages. We never succeeded. I think it was a combination of the new settings being more secure (which raises the question of how much the Russians had found out about our previous success) and the edge of tension having gone off our effort.

Elsewhere, Allied recovery teams regularly overran German sigint operations that were still chattering away, producing decrypts of mid-level Soviet Army Group traffic.

The timing of raids on German sigint centres was a precarious matter. If they were captured too early there was a risk that this would cut off a flow of valuable material that Bletchley was intercepting, or else would alert the Germans to the fact that the British knew more about their cyphers than was desirable. London was especially anxious to avoid freelance raiding activities that might be counter-productive. As early as May 1944 the London Signals Intelligence Board, the supreme governing board which met monthly to set overall British sigint policy, learned that some independently-minded British intelligence officers in the Middle East were planning to use the Special Operations Executive to raid enemy signals intelligence centres in the Balkans. Sir Stewart Menzies, who chaired the board, warned them sternly that operations against such centres were ‘highly undesirable’, and that action should ‘on no account be undertaken’ without prior personal authority from him.’

Bletchley’s corporate takeover of the Axis sigint effort was not limited to Germany. There were even greater TICOM dividends in occupied Italy.

 Many countries competed for the services of the talented Italian cryptanalysts. After the Italian surrender in 1943, some eighty Italian code-breakers under Major Barbieri continued to work for the Germans at a station near Brescia in northern Italy. At the end of the war in Europe they were at last interrogated in Rome, and proved to have a large quantity of material, including photocopies of the codebooks of Turkey, Romania, Ecuador and Bolivia. They had also reconstructed some of the codebooks from France, Switzerland and the Vatican, and had smaller amounts of British and American traffic. During the spring of 1945 Barbieri’s unit had been concentrating on French diplomatic traffic, ‘a large number being messages to Paris either from Bonnet in New York or from Catroux in Moscow’. This traffic offered insights into subjects as diverse as Soviet–Yugoslav relations, Soviet policy in Germany, French economic negotiations with the United States and French plans for exploiting the Saar coal mines in Germany.

With British encouragement, this precocious Italian unit worked on into the post-war period, without deviating from its French target. The diplomatic unit at Berkeley Street was already doing extensive work on Britain’s European allies, regarding them as either insecure or untrustworthy, or both. Much of this suspicion stemmed from a sense of indignation at their behaviour in 1940. In November 1944, Churchill wrote to Eden: ‘The Belgians are extremely weak, and their behaviour before the war was shocking. The Dutch were entirely selfish and fought only when attacked, and then for a few hours …’ General de Gaulle’s Free French government in exile, as other historians have shown, came in for especially close attention from the code-breakers during the war, and this continued into 1946. During the important diplomatic conferences that marked the end of the war, Jimmy Byrnes, the new American Secretary of State, was apparently more eager to see decrypted French material than anything else, concerned that Paris was likely to be working with Moscow.

 French traffic from Moscow was of great interest to London because the former French Air Minister, Pierre Cot, had indeed begun a special diplomatic mission to Moscow to examine the possibility of cooperating against Germany in post-war Europe.

French traffic provided the British and Americans with a fabulous window on the diplomacy of Western Europe.

 Indeed, in mid-1946 half the US Army code-breakers’ end product was based on intercepting French communications.

 Alarmingly, the French still seemed keen to develop a close relationship with Stalin.

 The traffic from French Embassies in Eastern Europe proved especially interesting. Typically, an intercept from the French Embassy in Tirana gave detailed information on the balance of power in the Albanian Cabinet and the waning power of the pro-Moscow elements, and intercepted French intelligence traffic sometimes offered information about the KGB.

 With the work on Soviet codes still gaining momentum, the chatter of other countries that were talking to Moscow provided insights into their thinking. On 13 August 1945, Edward Travis sent Joseph Wenger, the senior American naval code-breaker, a long missive about cooperation on post-war French and Dutch systems, and explained British plans ‘to increase the effort here, especially on French’, adding that British plans to focus on Paris ‘are going into effect at an early date’. French, Spanish, Portuguese and Latin American traffic was soon consolidated into a single group under Josh Cooper.

Major Barbieri was proud of the work of his Italian code-breakers against the French, but he pressed for more staff. So many of the best cryptographers, he complained, had been captured by the French in North Africa, adding, ‘the French are now employing them in their own service!’ Nevertheless, the British concluded that the Italians were ‘doing remarkably well with the limited reserves at their disposal’.

 By mid-1946 they were giving them new tasks, including Soviet traffic which came from military cypher machines at division level code-named ‘Taper’. British liaison officers with the Italians were working closely with code-breakers in Britain on the identification of new Taper groups. Senior Italian sigint officers knew that Taper traffic ‘which had been taken with so much depth and continuity for the past month’ was Soviet in origin, but many of their underlings were in a state of blissful ignorance about what they were collecting and who the ultimate customer was.

The efforts of TICOM were not exclusively directed towards raiding priceless sigint secrets from the Germans, the Italians and the Japanese. They were also concerned with protecting Britain’s own secret communications. Until late 1943, Bletchley Park regarded weak security as a problem restricted to Britain’s allies. But the ability to read German messages had revealed a number of unexpected security nightmares for the Allies. Ultra had shown Britain’s code-breakers that the Germans could read many of the codes of the Allies, such as those of the Soviets and the Free French. In Asia, terrible cypher security and serious human agent penetration ensured that Chinese codes were effectively an open book to the Japanese, even though Tokyo’s code-breakers were mediocre. Accordingly, keeping Britain’s secrets safe meant keeping them away from many of her allies, whose communications were being read by friend and foe alike.

By the autumn of 1943 the security situation looked much worse. The Italians had now capitulated, and captured Italian code-breakers revealed their successes against British codes. Captain Edmund Wilson, who helped to look after cypher security at Bletchley Park, held prolonged ‘conversations’ with Commander Cianchi, head of the Italian Cryptographic Bureau in Rome, and his staff during late 1943. Wilson explained that he could hardly call them ‘interrogations’, since Cianchi had given all of Italy’s secret information so happily and freely. Wilson said that ‘very valuable information’ on the breaking of British naval cyphers had been obtained, and that Britain was ‘extremely fortunate’ to have the cooperation of its former opponents. He pressed his colleagues to be ‘very careful indeed in the use they made of the information’ from these sources.

The TICOM raids into Germany later confirmed that British naval cypher security had been especially