Sonia’s Radio – Part IV

This instalment steps back to investigate a puzzling story about decryption of Soviet radio transmissions – the claim that Churchill put a stop to such activities immediately Hitler invaded the Soviet Union on June 22, 1941.

Attention to Soviet wireless transmissions was routine in the first period of WWII. The use of one-time-pads, which the Soviets had adopted for diplomatic and intelligence traffic after Prime Minister Baldwin’s ill-conceived disclosures in the House of Commons in 1927, continued to make nearly all messages undecipherable. Nevertheless, the Government Code and Cypher School (GC&CS) continued to perform interception of Soviet traffic.  In his history of the establishment, GCHQ, Richard Aldrich reports that, in October 1939, extra facilities were requested by the naval officer, Clive Loehnis, in order to handle increased volumes, and that operators with signals intelligence skills were even sent out to Sweden, where reception of Soviet signals was better. Aldrich adds that the influx of cryptographers from Europe meant that some French expertise was added to Bletchley Park after the fall of France, and that a section staffed primarily by Poles was set up in Stanmore, in North London.

The official history is very lapidary: there is no entry for ‘Russia’ or ‘Soviet Union’ in the Index of Volume 1 of the History of British Intelligence in the Second World War, and Professor Hinsley could record only that, before the war, work on Russia’s service codes and ciphers had been confined to two groups, one in India, and one in Sarafand, in Palestine. He suggested that, after the Nazi-Soviet pact, some modest progress was made: “Since then GC and CS had broken the Russian meteorological cipher, read a considerable number of naval signals and decoded about  a quarter of some 4,000 army and police messages, but  . . . it [this ‘local traffic’]  yielded nothing of strategic importance.” This observation does reflect an increasing interest, but also indicates that, unsurprisingly, no breakthroughs had been achieved over one-time-pads. As the September 2016 instalment of ‘Sonia’s Radio’ hinted, individual memoirs refer vaguely to attempts by GC&CS to decrypt more strategic Soviet traffic, but a reliable account of exactly what happened is very elusive.

In 1979, however, a startling and controversial statement appeared. In the above-mentioned history by Hinsley, hidden in a footnote on page 199, can be found the following: “All work on Russian codes and ciphers was stopped from 22 June 1941, the day on which Germany attacked Russia, except that, to meet the need for daily appreciations of the weather on the eastern front, the Russian meteorological cipher was read again for a period beginning in October 1942.” This astonishing assertion is a mixture of the precise and the vague – an exact date of a decision, but no indication of who made it. Moreover, it seems that the statement had been clumsily inserted at a late stage of publication, since the text is not properly aligned, as if something had been removed. Moreover, if the messages encoded with one-time-pads had been shown to be stubbornly intractable for fourteen years, what was the point of declaring that ‘work on Russian codes and ciphers was stopped’? Yet Hinsley’s enigmatic statement has pervaded historical consciousness to a large degree. What was the true story behind this claim?

The statement certainly merits some close parsing and analysis. If, indeed, the work was stopped on the same day that Hitler’s troops invaded the Soviet Union, how and why was such a decision, amidst all the tumult that must have been going on, made so swiftly? And how was it communicated so promptly to Bletchley Park, so that plans could be changed immediately? And was the implicit instruction that transmissions themselves would no longer intercepted, or did the restriction apply solely to decryption? And when were the restrictions removed, if ever? And for whose benefit was the decision made? Was it intended for Stalin to hear about, so that his trust in Britain’s support would be magnified? Or was it made from a fear arising from the belief that, if he ever discovered that efforts were being made to understand his diplomatic or other messages, he might . . . what? Have a huff? But was it not all a bit premature to assume that, before Stalin’s reactions to Barbarossa were even known, calling a halt to work on the coded messages of a country that had been Britain’s main subversive threat for over twenty years was a wise strategy? One can safely surmise that Stalin would have been astonished if Britain had indeed stopped trying to decode his traffic: it was not as if he would have withdrawn his army of spies as a reciprocal gesture of good will. Perhaps the decision was a bluff – an outward show of comradeship and trust, to be surreptitiously leaked to Generalissimo Stalin, while the secret programme was actually ordered to continue?

The essence of this momentous decision has been accepted by many historians and journalists, but not rigorously inspected by many. The first apparently to refer to it was the American historian Bradley F. Smith, who briefly expressed scepticism about the supposed decision in his 1983 volume The Shadow Warriors.  He wrote that it was difficult to take seriously the claim of a government that developed ULTRA that it had stopped work on all Soviet codes for the duration of the war. This was followed by Chapman Pincher, in his 1984 book Too Secret Too Long, where he pointed out that such a policy, made perhaps out of a naive belief that the Soviets would reciprocate such trust, may have enabled Stalin’s spies to perform their work undetected during the remainder of the war. Pincher, relying on information he received from Professor Hinsley, believed such a decision had indeed been taken, and that the Y Board devised the ruling after Churchill had made it clear that the Soviets should be treated as allies. Pincher even gained a confirmation from Dick White that that is what happened, although, since White was only Assistant-Director of MI5, in charge of B1 at the time, it is not clear how he was informed of the decision if no one else appears to have been aware of how it was made. In addition, it would have been highly unlikely that the Y Board, after receiving the directive from Churchill, would have met to discuss the issue the very same day that Barbarossa occurred.

Furthermore, Pincher echoed the essence of the edict as Hinsley presented it   ̶   that Soviet messages would no longer be decrypted, without any indication of whether transmissions would still be monitored, whether illicit or not.  Clearly a process of detecting and recording encoded transmissions had to be in place before any attempts were made to try to identify their source from call-signs and location-finding techniques, let alone trying to decrypt them. At this stage of the war, valuable information was being gained from the emerging technique of ‘traffic analysis’, which did not require decrypting of message texts. Moreover, since GC&CS realised that Soviet traffic was nigh undecipherable, with no breakthroughs in sight, an order to cease decryption efforts would have been a meaningless gesture, while traffic analysis, not proscribed by the edict, would still have been a valuable project. And messages were transcribed and stored for potential later analysis. Thus the emphasis on forbidding decryption seems something of a red herring.

Pincher also cast some doubt on Churchill’s intentions, by suggesting that he may have been alarmed by the decision (given his distrust of the Kremlin), again annotating that Professor Hinsley told him that ‘the MI6 chief or one of the Service Chiefs may have mentioned it to him verbally’ [sic: he presumably meant ‘orally’]. This is quite bizarre: the Prime Minister is described as making a clear policy statement, but then is surprised when he later learns it has been cast into practice. Pincher offers no explanation, and then goes off the rails even more, as his mission is clearly to implicate Roger Hollis in the concealment of Sonia’s radio traffic, attributing to him all manner of responsibilities that he did not have, such as decoding the messages himself.  He also seems to think that the Cambridge Spies would somehow have suddenly changed their attitude because of the ruling (when they had no control as to how their secrets were passed on), but he does not tell us how they learned of it. That is pure speculation.

One extraordinary segment in the story is the contribution by Anthony Cave-Brown in his 1987 biography of Stewart Menzies, ‘C’, more by what he doesn’t say as from what he does. (Menzies was the head of SIS, responsible for GCC&S, who took the ULTRA messages to Churchill personally.) There is no mention of Churchill’s edict in his story, no reference to Hinsley, and, though Cave-Brown is familiar with Read’s and Fisher’s biography of Dansey (Colonel Z), no statement on the possible leakage of ULTRA via Dansey’s Swiss network. Yet Cave-Brown does make the remarkable claim that, soon after Barbarossa, ‘’C’ had been able to read the Communist International’s secret wireless traffic with its supporters in Britain and elsewhere’, i.e. almost three years before the ISCOT project delivered any goods. Furthermore, he cites a diary entry by Churchill’s secretary, John Colville, dated September 9, 1941, that refers to information received from Desmond Morton (Churchill’s personal assistant for intelligence) concerning such information about Comintern orders from ‘secret sources’. Maybe Cave-Brown was under the impression that the intercepted traffic known as ‘MASK’ had continued beyond January 1937: as late as October 1942, Liddell was still referring to Comintern instructions coming ‘via courier or via the Embassy’. Or perhaps he was under the same misunderstanding as Michael Smith (see later) concerning overheard conversations at Communist Party HQ. This claim does not appear to be echoed anywhere else.

The next historian keen to delve into the story appears to be Anthony Glees. While researching his Secrets of the Service (also published in 1987), and aware of Pincher’s narrative, Glees also had the benefit of being able to contact Professor Hinsley, asking him who had given the order. Hinsley replied to Glees by saying that he ‘had no evidence as to who made the decision. Presumably it was taken by the Y Board.’ The plot now thickens. Is this not an extraordinary statement for an official historian to make? With no archival evidence, and no record of such a decision, to rely on hearsay would appear as an abdication of the historian’s responsibility. (I shall return to this issue when I investigate Hinsley’s assertions about ULTRA distribution in the next instalment of Sonia’s Radio.) Glees did actually gain confirmation from an (anonymous) SIS officer that the decision had been taken, and he thus investigated further. He also had the advantage of being able to interview Sir Patrick Reilly, who had been the personal assistant to Stewart Menzies from April 1942 until October 1943. Reilly’s line appeared to be, however, that, even if Soviet traffic had been monitored with any thoroughness, its impenetrability would have hindered any breakthroughs, and thus nothing about Soviet aims was lost to intelligence. In side-stepping the question, he thus shed no real light on the enigma, except for reinforcing the notion that the edict was practically of no consequence.

Conscious of how vital such a decision may have been in Britain’s failure to unmask Soviet spies, Glees returned to the key question of authority. He managed to induce Reilly and Lord Sherfield (who, while a future Ambassador to the United States, as Roger Makins would not appear to have been close to the action at the time, as Glees confirms) to agree that such a decision would have had to have come from Churchill himself ‘with the approval of either the Cabinet or the Joint Intelligence Committee and after consultation with ‘C’ [Menzies].’ With this judgment, however, Reilly and Sherfield completely contradict what Hinsley had told Pincher, namely that the Y Committee had made the ruling, and that Churchill learned of it later. Thus the issue of the edict’s being issued on June 22 has to be finessed: the storyline is dismally vague, and infected with speculation. Maybe Churchill communicated the decision privately to Bletchley Park via Menzies, and informed his cabinet later. Maybe there was no decision at all.

Glees skilfully analyses the question of why Churchill might have made the decision, and the implication that such considerations might have on his awareness that his intelligence agencies might have been infected by spies, concluding, along with Sherfield, that, since ‘you do not spy on your friends’, Churchill’s policy was eminently sensible. Glees also makes the very shrewd observation that, had the British policy-makers been allowed to read Soviet wireless traffic, they ‘might have picked up intelligence about the role of the Red Army in post-Nazi Europe’. One might wonder how seriously the Soviets were considering the shape of post-war Europe at a time when their own survival was at stake: not until the Battle of Kursk was won, in August 1943, might Stalin and his crew have had enough confidence in the outcome to believe that it might be able to define how it would bring the eastern states under Communist authority once the war was won. Thus Glees’s projections, working from a supposed edict from 1941, were quite imaginative, yet appear not to have been picked up by other historians.

Richard Deacon (the pseudonym of Donald McCormick), however, picked up Glees’s first point about not spying on allies, suggesting in The Greatest Treason (1989) that Churchill issued ‘a personal order that MI6 should cease to decode Soviet wireless traffic since it would be wrong to spy on friends’. Deacon than says that Roger Hollis (who was primarily responsible for monitoring communist subversion, and about to move into the new F Division set up by David Petrie) interpreted the decision as a political move on Churchill’s part to win friends on the left, implying, perhaps, that Churchill expected cryptanalysis to continue more discreetly. There was no doubt about growing sympathy for the Soviets at this time, but the idea of Churchill, for political reasons, making a public statement about a highly secret operation, simply does not make sense.

Yet what Glees grasped at is in fact exactly what happened. We know now that information about Soviet plans in eastern Europe was precisely what the British were able to gather – from decrypted Soviet transmissions, when the U.S.S.R. was an ally. We now know that this occurred in the West End of London, where an offshoot of Bletchley Park was set up in February 1942.  Commander Alistair Denniston (portrayed by Charles Dance in The Imitation Game) was effectively demoted from his leadership of GC&CS to establish the new operation, and to work on diplomatic and commercial ciphers instead. Nominally, Berkeley Street was used for analyzing diplomatic traffic, and nearby Aldford House for commercial messages, but Nigel West and others state that ISCOT operated from Alford House. ISCOT, named after the cryptanalyst who led it, Bernard Scott (who was later Professor Mathematics at Sussex University), ran from April 1943 until after the end of the war, and successfully intercepted and decoded Comintern messages to Soviet agents working behind Nazi lines.

Moreover, the records tell us that some monitoring activity antedated this programme. The Government Code and Cypher School admitted to its partners in Canada and the United States that it had indeed been intercepting and analyzing traffic from enemies, allies and neutrals alike.  John Bryden (in Best-Kept Secret) shows us a letter written on June 3, 1942 by Commander Denniston (then at the office in Berkeley Street)  that confirms that his group was spying on the messages of not only the enemy (Germany and Japan), but allies and neutrals as well, including Bulgaria, France, Hungary, Spain, Switzerland, and Russia. In his 2010 history, Richard Aldrich (who incidentally does not mention the rumoured edict at all) asserts that Britain was deciphering USA diplomatic traffic named ‘Grey’ throughout 1941, for Churchill’s particular appreciation. In fact, British and American cryptanalysts had been working on each others’ ciphers since they were Allies in the First World War. The claim about ‘not spying on friends’ as an important aspect of diplomatic policy is thus shown to be completely spurious. The USA was always more of a ‘friend’ than the USSR.

Very little has been written about the ISCOT project itself, although a voluminous set of transcripts of the traffic can now be inspected at the National Archives (HW 17/53-67). What is extraordinary is that, when the MI5 & SIS officer John Curry wrote his private history of MI5 in 1946 (not published at the time), he gave a comprehensive account of the whole programme (without revealing the codename ISCOT or the locations), even admitting that ‘early in 1944 G.C. & C. S. officers succeeding in reading some of the material’. He described the complete organisation of the ‘post-Comintern’ set-up, and the substance of the messages – something that appears to have been almost completely ignored by historians  ̶  and in fact Curry referred to a rich report he himself wrote about the project before he left SIS’s Section IX in November 1944. (It was thus probably Curry, not Archer, who wrote the report referred to by Curry’s successor, Kim Philby – see below.) The text of Curry’s history was not published until 1999, and was released to the National Archives the same year, but it had presumably been available for intelligence insiders in the intervening decades. Coincidentally (or was it not so?), the source texts of the decrypted transmissions were released at the same time. Not until 2011, when Ralph Erskine and Michael Smith published The Bletchley Park Codebreakers, did an account appear (Chapter 2) of the pre-war and wartime activity on Soviet codes, with credit given to Curry. This piece concentrates, however,  more on Curry’s disclosures on the 1930s MASK traffic, with only a few final terse sentences on the experiences at Berkeley Street, and no mention of the term ISCOT itself.

In the ISCOT files can be found a fascinating series of messages, dating from July 1943 onwards – and decrypted on some occasions as little as a few days afterwards  ̶  that show that, even though the Comintern had been officially dissolved in May 1943, it vigorously lived on, concealed as ‘Scientific Institute 205’, with Dimitrov still in charge. Stalin prepared his agents behind enemy lines in Europe to take power in their respective countries after the war, for example issuing orders that provisional governments must be initially set up as ‘democratic’ and not ‘communist’. It is clear that the highly-secure medium of one-time-pads was simply not applicable in these situations, because of the geographically spread and dynamic organisation that simply would not have been able to follow such disciplines. (Indeed, one of the messages with great alarm draws attention to loose encryption techniques, and how they must be repaired.) The radio operators used a hand-cipher based on grids and extracts from Shakespeare: one-time-pads were not introduced until the end of the war. Thus the challenge to the cryptographers at Aldford House were not so great as those they faced when analyzing official Soviet diplomatic traffic.

Some of the background to the whole exercise has been revealed in a series of articles that have appeared in specialist intelligence magazines, namely the Journal of Intelligence History, and Intelligence and National Security, between 1995 and 2013. The project became controversial later, and a dispute still exists as to whether or why the British Government did not incorporate the obvious messages from the ISCOT decrypts into their plans and negotiations concerning post-war Eastern Europe (the point that Glees latched onto without being aware of the project back in 1983). John Croft and Herbert Romerstein (two authors of the articles mentioned) themselves take opposing stances on the amount of damage done. But the fact that the existence and substance of the ISCOT transcripts seem to have been completely overlooked in all histories of the Second World War (even after 1999) would suggest that their content has been a subject of some embarrassment to the Foreign Office and to SIS. In his 2002 memoir, Know Your Enemy, Percy Cradock, who was chairman of the Joint Intelligence Committee from 1985 to 1992, echoes the story that ‘work on Russian ciphers had been given up as early as June 1941’, admits the lapse revealed by the VENONA project, but shows no awareness of the ISCOT transcripts, and concludes that ‘only low-grade information came via Sigint’. How could he possibly not have known about the programme?

Ironically, it was apparently the spy Kim Philby who first broke the news, in 1968, although in a veiled way. (Alistair Denniston’s son, Robin, drew attention to Philby’s shocking breakthrough, which was the first indication to the public that a body like GC&CS even existed.) Without using the term ISCOT (or even Bletchley Park!) Philby declared in his memoir, My Silent War, that Section IX of SIS had access to the transcripts, and that he instructed Jane Archer to compile a detailed analysis of the traffic, to keep her busy, presumably believing that the exercise could do no harm to him and his colleagues in espionage. He provided firm evidence that he was familiar with the texts, commenting that ‘despite the efforts of OSS and SOE to buy political support in the Balkans by the delivery of arms, money, and material, the National Liberation movements refused to compromise’. (It should be noted that the Chronology attached to Philby’s memoir misleadingly states that Section IX was set up in 1945, and that Philby headed it then. Chapter 7 rightly hints that it was set up in 1943, under ‘Currie’ [actually ‘Curry’], and that Philby took over in November 1944.) Moreover, Philby had a good relationship with Denniston in the latter’s new job: the reason he made contact was that, when investigating some Nazi reports that had been given to Allen Dulles’s OSS office in Berne, Switzerland, Philby decided to pass them by Denniston to verify their authenticity. Denniston was able to match the texts with recently decrypted messages, and thus increase the success of his department. Sadly, despite his anti-communistic instincts, Denniston would come to trust Philby: the Dulles exercise must have contributed. And ironically, it was his son who helped to get Philby’s memoir published in England. Cave-Brown suggests it was done partly to spite Menzies for how his father had been treated.

While Archer’s (or Curry’s) report has not come to light, the episode indicates at least three things. One, that its revelations might well have proved embarrassing to intelligence officers after the war, especially if the Comintern exchanges had not been shown to the Joint Intelligence Committee. Two, that the ISCOT exercise would quickly have come to the ears of Philby’s masters in Moscow, who presumably then did not consider the exposure dangerous enough to need to change their ciphers. It might have pointed to a leak if they had done so. In addition, the Soviets perhaps believed that they had Roosevelt and Churchill on the run, and that their current Allies against the Nazis, even if they did divine the Soviets’ true intentions, would have neither the guts nor the resources to challenge the Communist expansion at the end of the war. Only in 1945 did Soviet Intelligence switch to one-time-pads for ‘Comintern’ traffic, and thus make the transmissions unreadable again. The third conclusion one could make is that the Soviets would have definitely been alerted to the fact that British cryptographers were probably working on more Soviet traffic than that of the Comintern, despite any claims to the contrary that may have been leaked to them, including the now questionable edict emanating from Churchill or the Y Committee. And that might have affected their approach to security, and their use of radio elsewhere.

The move of Denniston to London has always been problematical, as if he had been rather brusquely sidelined. But another fact hints at more disciplinary action: while he was the longest-serving head of GC&CS (or GCHQ, the name granted to the establishment after the reorganisation), he is the only leader not to have been knighted, which is a quite extraordinary insult to someone who had delivered extremely well for most of his long career. Even if it is true that new management was required with the growth at Bletchley Park, and Denniston was not only uncomfortable with the task, but also suffering from severe illness, there was no reason for him to be treated so shabbily, with a demotion and reduction in pay. His replacement by Edward Travis in 1942 has been interpreted by most historians as a necessary move for greater efficiency. The insult is inexplicable: Travis was made director of GC&CS in March 1944, and knighted three months later. Denniston had led GC&CS for twenty years. Was there something else going on?

The more serious histories are unfortunately not very informative over the reasons for the reorganisation, and what caused Denniston’s demise. His new set-up, known as the Government Communications Bureau, rapidly grew in size. Seventy persons were rapidly installed, growing soon to two hundred, but Denniston’s son, Robin, reports that, by the summer of 1942, this had swelled to five hundred (admittedly on his father’s evidence) – certainly no humble backwater for a disgraced bureaucrat. Other sources contribute to the lack of clarity.  Ronald Lewin, in Ultra Goes to War (1978), understated the whole conflict, merely noting that ‘illness caused Denniston  . . . to be moved to quieter fields’. P. W. Filby wrote (in Intelligence and National Security): “Both [de Grey & Travis] felt that the organisation had become too much for Denniston, and finally it was decided to make Travis director at Bletchley (military) and Denniston head of the Diplomatic sections, with a small [sic] staff to be housed in Berkeley Street, London. . . . He was released from Bletchley and went to Berkeley Street without any ceremony. Our section, headed by Patricia Bartley, followed him in February 1942 and found rather a bitter man . . .”  Hinsley’s entry for Denniston in the Dictionary of National Biography surely does not perform justice to the whole episode, or Denniston’s subsequent achievement, stating merely that ‘from all accounts, Denniston is judged to have done a fine job at Berkeley Street.’  The newer entry in the Oxford Dictionary of National Biography, updated by Ralph Erskine, is more laudatory: ‘. . . he brought unusual distinction and expertise, as well as devotion, to his work’, but it sheds no light on the fact of Denniston’s being rebuked so sharply.

So what caused Menzies’s disciplinary action? Anthony Cave-Brown’s biography indicates that Menzies was far more annoyed with Welchman, Turing, Milner-Barry and Alexander for bypassing the management chain (when they sent a memorandum about resources directly to Churchill) than he was with Denniston for not addressing with more determination the cliquey set-up at Bletchley Park. Moreover, Travis had been as responsible for the dysfunction as Denniston was. Yet Menzies made Denniston the scapegoat, despite their long friendship, in a move that Cave-Brown characterises as ‘one of ‘C’’s unhappier decisions’.  Sebag-Montefiore suggests that it was Denniston’s clumsy efforts to discipline Dilly Knox, and control the analysis and distribution of Knox’s decrypts, that pushed Menzies to demote him. It is all very murky, but the conclusion must be that Hinsley had obviously been told to say nothing about ISCOT, Denniston’s most successful project, even though the neutral reader might conclude that the whole programme was an achievement worth celebrating. The lesson is that we should not necessarily trust ‘official historians’.

Evidence appears of a continuing dispute over the relationship with the Soviets. In his memoir about his father’s career, Thirty Secret Years, Robin Denniston suggests that a long-running feud existed between Menzies and Denniston (thus undermining the strength of their long friendship), and that the head of SIS was clearly the person keen to demote and humiliate the head of GC&CS. Denniston had apparently been very critical of government officials who had given away the secrets of their cryptography to the Soviets – referring, no doubt, to the contemporaneous venture to Moscow to exchange information that was undertaken by Edward Crankshaw, as well as, possibly, the controlled leakage of ULTRA via agents in Switzerland that has been publicised in several accounts (but denied by Hinsley). Denniston, it should be remembered, had been in charge of GC&CS in 1927, when the ARCOS raid occurred, after which Stanley Baldwin disastrously explained in the House of Commons that Soviet codes had been broken. Ever since then, Soviet messages had confounded the cryptanalysts, and Denniston, infuriated by the senseless boast, had maintained his mistrust of politicians. It might thus suggest that the feud at Bletchley Park extended beyond mere responsibilities and local rivalries. There would be a camp that believed utter co-operation with the Soviets was necessary in the campaign to beat the Nazis, while another faction would have pointed out that the Soviet Union was only a temporary ally, and still a permanent adversary. The former group would have been expanded and energised by the influx of so many Oxbridge intellectuals at the beginning of the war.

Did Menzies and Denniston perhaps disagree about the possible exposure of ENIGMA by sharing secrets with the Soviets? By some accounts, Menzies also strongly advised against such co-operation, yet he was not a very forceful personality, and would not have stood up to Churchill. On the other hand, Denniston, who had his allies, too, was presumably encouraged to continue the efforts into attacking Soviet transmissions at Berkeley Street. (Travis also quickly recognised the Soviet threat.) Did Denniston perhaps speak out of turn about Menzies’s relationship with Dansey, and the exploit in Switzerland, and incur Churchill’s displeasure?  Or was the reprimand over Denniston’s perhaps too hasty rejection of Turing’s computational approach to decryption? Or was the dispute perhaps over sharing information with the Americans? Denniston had realised, even before the USA entered the war, that Great Britain and the United States would have to share the cryptographic load, and he had undertaken a visit to the US early in 1941 to discuss achievements and approaches for work allocation. Perhaps Menzies objected to this initiative, and Denniston disobeyed orders?

Denniston’s DNB entry describes the ‘reluctance’ from others concerning this overture, which ironically was soon justified, since the USA entered the war at the same time that he fell to the sword.  It is true that Philby wrote that Menzies added a final clause to the charter for Section IX of SIS, namely that he ‘was on no account to have any dealings with any of the United States services. The war was not yet over, and the Soviet Union was our ally’, but Philby’s testimony must not be treated as unequivocally reliable: the statement should probably be interpreted as deception imposed by Philby’s masters. In any case, the communist sympathisers took over in Section IX. The anti-communist Curry was out, and Robert Carew-Hunt (whom, along with Oliver Strachey, Donald Maclean had approached at Bletchley Park as possible recruits to Moscow Centre, which, even if the approaches had been rejected, must cast immediate doubt on the degree of their loyalty) joined Philby’s team. But no explanation does justice to the issue. And if some subtle subterfuge had been embarked upon, it surely would not have debarred Denniston’s knighthood. One has to conclude that Churchill was somehow involved with the decision.

So what else has been written about Churchill’s supposed edict? Michael Smith, in New Cloak, Old Dagger (1996), wrote that ‘a long drawn-out debate’ ensued over whether Soviet traffic should continue to be monitored, one that lasted until early 1942, which suggests that Churchill was not involved at all, the discussion occurring at a lower level. Smith indicates that the Poles at Stanmore were delegated the task of intercepting [sic] and attempting to decipher Soviet military transmissions, thus perhaps finessing the edict from on high that the British should cease such activities. Yet Smith goes a little over the top, next asserting that ‘within weeks, the Metropolitan Police intercept site at Denmark Hill and the Radio Security Service had begun to pick up messages between Moscow and its agents in Britain’. This claim (which would be quite extraordinary, if true, and very germane to the case of Sonia’s Radio) appears to have been based on a misunderstanding of a boast overheard at Communist Party HQ by the spy Oliver Green, who later admitted he had invented the whole story. There is no evidence that any illegal wartime transmissions between Soviet couriers and Moscow (as opposed to communications via the Soviet Embassy) were detected or decrypted – outside the mysterious case of Sonia.

More recently, Smith has refined his message. In the 2011 book that he co-edited with Ralph Erskine, The Bletchley Park Codebreakers, he claims that, despite Churchill’s order, coverage of Soviet traffic initially increased. (Somewhat surprisingly, he does not suggest that the edict was never issued, but that it was ignored.) A lengthy debate then ensued that lasted for months: the Russian section was not closed down until December 1941. (But maybe it was simply moved, and in fact active prior to the official date of April 1943.) He again grants the Poles the task of intercepting traffic and trying to break it, and indicates that the British kept two groups monitoring known Russian frequencies at Scarborough and Cheadle. He then introduces the history behind ISCOT in more detail (again without identifying it), and now clarifies his previous statement, saying, at some time in 1943, the Metropolitan Police intercept site at Denmark Hill and the Radio Security Service had begun to pick up messages between Moscow and its agents in Europe (subtly annulling his 1996 message about spies in Britain). This was ‘the Russian group business’ that Curry referred to. Yet Liddell discussed the topic in his diary as early as December 1942, using the exact same terminology, and expressing concern that RSS may have talked out of turn about it, which tantalisingly suggests that the programme had started earlier. Nevertheless, apart from affirming that British code-breakers ‘were again reading Soviet traffic’ by the summer of 1943, Smith draws back from any deeper analysis. His chapter stops there.

Is that the whole story? The disputations at Bletchley Park must be placed in a broader context of tensions. Disappointment in collaboration with the Soviets soon set in. After Barbarossa, attempts were made by both SOE and SIS/Bletchley Park to build relationships and exchange information with the NKVD. It took several months before it became clear that the Soviets did not want to share much information. By the second half of 1943, military planners were starting to consider the post-war threat that the Soviet Union might constitute. The growing dissatisfaction and feuding at Bletchley Park was not exclusively related to overload of the organisation: major fears about cipher security, and the possibility of leakage of Enigma secrets through the Soviets to the Germans, were a real concern, and the premature gestures made to the USA indeed did upset some. MI5 and SIS were frequently at loggerheads. MI5 was still very insistent on tracking illicit radio transmissions that may have had communist origins, while RSS was almost exclusively focussed on Nazi signals, something about which Guy Liddell constantly expressed concern. Liddell was also worried that new burst-mode wireless techniques used by Communist agents might overstretch RSS, and SIS’s tight control of ULTRA decrypts caused major rifts between the two organisations.  Lastly, the entry of the USA in December 1941 into the war changed the game. It made new awareness of the opportunities: the first Allied wireless conference was held (but without the Soviets) in Washington in April 1942, and GC&CS learned that summer that the Americans were intercepting all Soviet traffic, and that they were very anxious to crack the codes. The two countries set up parallel teams to share analytical work in this area in February 1943. In addition, the USA was very critical of co-operation between Britain and the Soviet Union, such as the scientific treaty of June 1942, and made its opinions felt. If Churchill knew what was going on, he did not complain, or shut the activity down.

So what was Hinsley thinking? He was in fact at the hub of all the controversy in December 1941. Nigel West tells us that, while Menzies was waiting for his special inquiry, undertaken by Major-General Martin, to be completed, Hinsley took over as ‘intelligence supremo’, the same month that the Russian section was closed down. (Hinsley was only twenty-two at the time – a little young for a ‘supremo’, one might think.) How could he have written what he did about the edict with a straight face, and later tried to defend it? Maybe he had a pang of conscience because he had backed the wrong horse, and wanted to conceal his position. Or maybe he was simply told by his political masters that this was the official story to tell, in the belief that the true facts about Berkeley Street and ISCOT and ULTRA distribution and US-UK collaboration and Sonia’s Radio would never see the light of day. For, on all grounds – historical evidence, motivations, outcomes, politics, pragmatics, security – the story of the edict simply does not make sense. As with the other cover-ups over Fuchs and communist spies, maybe there was a greater reputation to be protected, and a pretence required that claimed that ignoring domestic transmissions from Soviet spies was the order of the day. Fortunately, some officers saw fit to release some relevant archival material, and thereby, alongside the memories of so many wartime Bletchley Park servants who had been hushed for so long, but had then been encouraged to talk, a more accurate picture of the decisions of 1941 is gradually being revealed.

New Sources:

Journal of Intelligence History

Intelligence and National Security

Kahn on Codes, by David Kahn

Fighting to Lose, by John Bryden

Best-Kept Secret, by John Bryden

Enigma: The Battle for the Codes, by Hugh Sebag-Montefiore

Burn After Reading, by Ladislas Farago

The Deadly Embrace, by Anthony Read & David Fisher

Shadow Warriors, by Bradley F. Smith

Colonel Z, by Anthony Read & David Fisher

The Secrets of the Service, by Anthony Glees

My Secret War, by Kim Philby

Too Secret Too Long, by Chapman Pincher

Treachery, by Chapman Pincher

Know Your Enemy, by Percy Cradock

The Greatest Treason, by Richard Deacon

 ‘C’, by Anthony Cave-Brown

MASK, by Nigel West

P.S. Last month, I listed three items that merited further attention, and here provide an update:

1) A reader sent me some very provocative and potentially useful statements concerning Sonia, apparently sourced from Soviet intelligence archives. This reader (who prefers to remain anonymous) has peered deeply into Sonia’s case, and has given me many useful pointers. He provided extracts from the archives of Soviet military intelligence (that he translated himself), with precise references, which on the surface look very convincing. Yet I am not persuaded of the authenticity of the entries: some of the dates do not make sense, and the relationship between the GRU and Sonia sounds phony. It is possible, I suppose, that the entries are a combination of proper notes to file, and spravki that were added later, for reasons of disinformation. I have not succeeded in learning how this reader acquired the documents, or how he addresses the apparent contradictions. I shall pick this item up again in 2017.

2) A 2014 book I read about WWII counter-espionage prompted some fresh reflections on Trevor-Roper and the Double-Cross System. This book was John Bryden’s Fighting to Lose, which claimed to show that the Abwehr (the German Intelligence Service) was deliberately aiding the British effort to win the war, and that the Double-Cross System had been seen through by the Germans, and was in fact a failure. Part of the Abwehr’s deception exercise (according to Bryden) was to feed messages that used antiquated codes, one outcome being that GC&CS dismissed Trevor-Roper’s and Gill’s ‘breakthrough’ because they recognised that such codes had been decrypted in WWI. This assertion is made with utter confidence, but is at variance with all other accounts of the clash between RSS and GC&CS that I have read. I again defer closer inspection of this highly controversial item, which may shed fresh light on causes for feuding between Denniston and Menzies, until next year.

3) My attention had been drawn to an archive freshly published (by the NSA) on German wartime intelligence. For those readers who may not be aware of it, it can be found at I have dipped into what is a remarkable trove, but not made any organised study of it yet. Another task for 2017.                    © Antony Percy, 2016

The customary set of new Commonplace entries can be found here.


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2 Responses to Sonia’s Radio – Part IV

  1. Michael P

    The final line in Note 1 to the PS of your November 2o16 posting reads “I shall pick this item up again in 1917”. Intentional (in view of the comment in Note 2 that ‘they recognised that such codes had been decrypted in WWI’), or just back to the future?

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