Before that I know of only one reference to my father’s work, and that was in an unkind memoir by the Soviet spy Kim Philby published in 1968. Philby revealed, quite casually, what the government had till then maintained strict secrecy about – the existence of BP in general and the split of its service from its diplomatic work in 1942. Philby realised that the German diplomatic intercepts he had collared from Switzerland would be right up my father’s street and sent them to him for analysis: which he did, full of enthusiasm and demanding more, so that he and his team were then able at last to break ‘Floradora’, the German diplomatic cipher. No-one seems to have noticed this illegal and deliberate breaking of the Official Secrets Act by Philby, by that time very much a persona non grata in Whitehall, though his book was duly published in the UK, the USA and in translation. So 24 years after my father’s retirement, he could have read something about himself no-one else was supposed to know about. But by 1968 he had died.
I did not publish My Silent War myself but I helped Philby’s agent find an English publisher. By this time I was keen to put my third-hand knowledge of British sigint to good use in my own career as a publisher, but even keener to see some rehabilitation of my father’s career in secret intelligence. Though I did publish Winterbotham’s book in 1974 while at Weidenfeld, I was happy to let other publishers build the new public interest in spies and spying – fiction as well as non-fiction. So Gordon Welchman’s book The Hut Six Story, on which I advised as to its early chapters, came out from McGraw Hill in 1982, and Peter Calvocoressi’s Top Secret Ultra from Cassell in 1980.
The magisterial primary source for BP went to OUP after I had retired from the Press: Codebreakers, edited by Harry Hinsley and Alan Stripp, contained Hinsley’s deep understanding of what made BP tick, as well as many first hand accounts of the work there. It was published in 1991 and later Michael Smith’s Station X (1998) and Smith and Erskine’s Action This Day (2001) added to the tapestry of wartime memories. These are the primary source for any account of BP’s wartime activities.
For secondary sources, the leader is Ronald Lewin’s Ultra Goes To War (1978) which went to Hutchinson; while David Irving’s great account of Churchill in 1941 (quoted in chapter 2), a source wrongly avoided by most other historians because of the author’s damaged reputation and right-wing political views gives a definitive account of Churchill’s daily use of Ultra through the fraught months of that year. Irving discovered new PRO files (HW14) released under the freedom of information act detailing Bletchley’s information on Wehrmacht intentions and achievements, and relates these to Churchill’s conduct of the war in the months before the Soviet Union and the USA joined the Allies. Another excellent secondary source is Jozef Garlinski’s Intercept (Dent 1982).
Ralph Erskine continues to keep an expert eye on all new relevant releases of HW and other secret wartime files, and there will certainly be others after the publication of this book. There are now 150,000 diplomatic decrypts in HW12 alone. But one has to start and stop somewhere, and there seems enough evidence of the importance of my father’s wartime work in Bletchley and London, to stop here.
All these authors and researchers are concerned with the importance of signals intelligence in the conduct of foreign policy in peace and war. But not all historians share this view: in fact most of the fashionable historians of the 1990s consistently ignore the whole subject, and go for biographies of earlier statesmen and imperialists. Christopher Andrew regrets that the main streams on western historiography bypass his subject comprehensively.
So do I. But perhaps the loss is theirs, not ours. However, even the most sceptical investigative historian must note the appearance of intercepts on the desks of the highest in the land; before they could be used, new skills at GC&CS and elsewhere in cryptanalysis extended activities and expertise into the wider task of providing relevant messages, requiring detailed knowledge of the mindset of senders and recipients alike, the exact state of whatever emergency or situation is being targeted, the ‘ministerial requirements’ and their representation by officials, their occasional emergence as official jargon and disappearance when duly burnt after reading, their re-appearance in Parliamentary answers, in obscure references still lurking unweeded in Foreign Office files, or muttered at a diplomatic reception, or pillow talk between clandestine lovers.
Fact here may seem to merge into fiction, but the distribution of diplomatic intercepts throughout the chancelleries of many powers may suggest an interesting new angle on both the conduct and study of international diplomacy, both in war and in peace. Spy fiction is a vast field but only John le Carré understands the uses and abuses of diplomatic eavesdropping via signals intelligence.
Postcript
The McCormack visit to Bletchley Park and Berkeley Street in May 1943 marks the end of the currently available record of US/UK signals intelligence co-operation, though in fact such co-operation continued throughout the rest of the war, and beyond, through the whole cold war, and we must presume Arlington and GCHQ Cheltenham are still in daily communication as they strive to serve the security of their countries and the ‘special relationship’ with new targets, mostly of the anti-terrorism variety. This special relationship is the major theme of this monograph on my father’s secret work from 1914 – 1945, as are the other principles for the good conduct of diplomatic eavesdropping on which my father instructed his colleagues, his superiors and his American counterparts, and which have all played continuing parts in the special relationship.
Whether the British public feel they have benefited from the Blair/Bush axis is not something for this monograph, but what needs remembering is that in 1939 there was no possibility of such relationship. The USA was bent on isolationism and keeping neutral, the British thought the Americans loud and vulgar and unreliable, but more intelligent views - those for instance of Winston Churchill - prevailed. My father’s two transatlantic visits of 1941 totally changed his views of America and Americans. He had had no previous experience, had never visited the country, his political interests were all European, as were those of most in Whitehall. So the change, though slow to mature, started violently when America was dragged into the war by December 1941 and there has hardly been a harsh word ever since.
What my father would have thought between McCormack’s visit in 1943 and his retirement two years later he certainly kept to himself. He was not a communicative man, even to his family and close friends. I hope he feels something like satisfaction, wherever he now is, that his remarkable contribution in changing the course of world history in 1916 and 1941 has been, however inadequately, acknowledged.
The influence of my father’s work continued long after his retirement and is still evident in the vital importance sigint has for the security services of the UK, the USA and a score of other developed nations, great and small. A leading sigint historian, Christopher Andrew, observed that while the main Japanese diplomatic cipher was broken and extensively publicised in the Pearl Harbor enquiry in 1946, only a few actually traced the origins of successful American sigint from Room 40 in WW1, which hastened American entry into the war, to British BP’s success with Enigma and Ultra from 1941, which materially aided Allied victory in 1945. But the story not only does not stop there, it is only the beginning of a huge postwar international surveillance operation, sparked by BP and aided by an American discovery of a major Soviet spy network in the USA. A cryptanalyst called Meredith Gardener deciphered messages, known as ‘Venona’ which revealed the identity of ‘Homer’ as their most important agent, Donald Maclean. This was part of the unmasking.
The US/UK sigint alliance forged in WW2 meant that Clement Attlee, the British PM 1945-50, knew more about the achievements of postwar American cryptanalysts and Soviet espionage against the USA than the President.
Only 10 years earlier my father had facilitated this sigint superiority over his American counterparts by touring British universities looking for mathematicians and linguists to work for him at BP on the Enigma cip
her. His long-term colleague Josh Cooper wrote after the war that it would be hard to exaggerate the importance of this recruiting drive for the future development of GC&CS, naming Gordon Welchman and Alan Turing as outstanding recruits. Later this work was overlooked but my father’s critics ‘did not realise that Denniston, for all his diminutive stature, was a bigger man than they’.
After the BP crisis of February 1942, and more sophisticated recruitment procedures, the numbers at BP increased in 1943 to over 5,000, in 1944 to 7,723 and by January 1945 to 8,995, after which GCHQ managed to escape from the control of ‘C’ and the even more frequent management problems of the whole SIS under Menzies. Throughout the Cold War GCHQ continued to service its customers in Whitehall and Washington. It was divided into five main directorates, moved house several times and still provides a valuable sigint service from what was, in the view of historians, the jewel in Britain’s wartime intelligence crown.
After the war geopolitical concentration was on an increasingly hostile Soviet Union. GCHQ was relocated from Bletchley first to Eastcote in north London, and later to Cheltenham, and became an independent international surveillance operation separate from Ml6, although still under Foreign Office control.
The Soviet nuclear bomb took all the western allies by surprise in late August 1949, and by that time the Soviets massively changed their codes and cipher security, eliminating most of the channels the west could read, including some machine-based mid-level military systems. GCHQ was thereupon directed towards Arab nationalism and later the Zionist movement, while Chinese and Soviet radio traffic was intercepted by its Australian counterpart as well as the British sigint centre in Hong Kong.
GCHQ’s new interest in electronic intelligence and airborne sigint lasted throughout the 1950s and 1960s, partly because most high-grade ciphers, and OTPs, still remained unbreakable. But ‘BJs’ were still circulated to specific users in government in the same blue-jacketed files as they were in my father’s day prewar, and make daily reading for all concerned with our national security.
At BP my father’s sure touch in finding the best recruits bore further fruit when two BP veterans, Clive Loehnis and Leonard Hooper, were successively promoted to the top job, while it is estimated that in the Soviet Union 350,000 experts applied their minds to similar work breaking the ciphers, increasingly sophisticated, of the western allies, its former enemies, now uneasily becoming friendlier. Anglo-American sigint extended throughout the Cold War and into the Iraq war. By 2000 all GCHQ’s activities were brought together on one site in Cheltenham - a vast new circular building with an open centre, and underground slip roads - the largest ever government private and public investment initiative costing £330 million to build and countless more millions to operate.
Any links between this vast new establishment at Cheltenham and the 100 or so cryptanalysts who manned BP in 1939 is beyond the scope of this monograph, and I doubt whether my father, at the ripe age of 125 would be much interested. But I hope he would approve of this attempt to link his 30 secret years with the 90 years in which British signals intelligence has proved such a valuable government tool, in peace as well as war.
List of Abbreviations and Terms
AGD Alexander (Alastair) Guthrie Denniston.
BP Bletchley Park, WW2 home of the Government Code and Cipher School, Britain’s inter-Service code-breaking organisation.
BJ Blue Jacket, diplomatic translation done by the GC&CS
C Head of MI6.
COS Chief of War Staff.
DID Director of the Intelligence Division of the Naval Staff. Later renamed DNI.
DNI See DID.
ENIGMA German cipher machine.
FO Foreign Office.
GC&CS Government Code and Cipher School (now GCHQ).
GCHQ Government Communications Headquarters.
JAC Joint Analysis Centre.
JIC Joint Intelligence Centre.
JIG Joint Integration Group.
MAGIC The cover name for translations from Japanese diplomatic messages.
MI Military Intelligence.
MI5 Department of British Security services responsible for counter-espionage within the UK..
MI6 The British Secret Service responsible for security and espionage services outside the UK..
OTP One-time pad.
PRO Public Record Office, Kew, London (National Archives).
SIGINT Signals Intelligence.
ULTRA Cover name for intelligence derived from high-level cryptanalysis.
WSC Winston Spencer Churchill.
WO War Office.
W/T Wireless Telegraphy.
Bibliography
Andrew, Christopher Secret Service: The Making of the British Intelligence Community. Heinemann 1985
Beesly, Patrick Room 40: British Naval Intelligence 1914-18. Hamish Hamilton 1982
Bennett, Ralph Behind the Battle: Intelligence in the War against Germany. Sinclair Stevenson 1994
Bryden, John Best Kept Secret: Canadian Secret Intelligence in the Second World War. Lester (Toronto) 1993
Cairncross, John The Enigma Spy. Century 1997
Calvocoressi, Peter Top Secret Ultra. Cassell 1980
Cave Brown, Anthony Bodyguard of Lies. Michael Joseph 1968
Clark, Ronald The Man Who Broke Purple. Little, Brown (Boston) 1977
Copeland, B. Jack (Ed.) Colossus: The Secrets of Bletchley Park’s Codebreaking Computers. Oxford University Press 1997
Denniston, Robin Churchill’s Secret War. Sutton 1997
ibid Yardley on Yap. Intelligence and National Security 9, no. 1 (1994)
ibid Three Kinds of Hero: Publishing the Memoirs of Secret Intelligence People:
Intelligence and National Security 7, no. 2 (1992)
ibid Fetterlein and Others. Cryptologia Vol. 19, no. 1 (1995)
Erskine, Ralph (with Michael Smith) Action This Day: Bletchley Park from the Breaking of the Enigma Code to the Birth of the Modern Computer. Bantam Press 2001
ibid Churchill and the Start of the Ultra-Magic Deals. International Journal of Intelligence and Counterintelligence 10, no. 1 (1997).
ibid What did the Sinkov Mission receive from Bletchley Park? Cryptologia Vol. 27, no. 2 (2000)
ibid The Poles Reveal their Secrets: Alastair Denniston’s Account of the July 1939 Meeting. Cryptologia Vol. 30, no.4 (2006)
Erskine, Ralph, & Freeman, Peter. Brigadier John Tiltman: One of Britain’s finest cryptologists. Cryptologia Vol. 27, no.4 (2003)
Hinsley, F. H. (with Alan Stripp) Codebreakers: The Inside Story of Bletchley Park.
Oxford University Press 1993
Irving, David Churchill’s War: Triumph in Adversity. Focal Press 2001
Kozaczuk, Wladyslaw. Enigma: How the German Machine Cipher Was Broken, and How It Was Read by the Allies in World War Two; Warsaw, Ksiazkai Wiedza 1979
Lewin, Ronald Ultra Goes to War. Hutchinson 1979
ibid The American Magic. Hutchinson 1986
Smith, Bradley The Ultra Magic Deals: the Codebreaker’s War and the Most Secret Special Relationship 1940-6. Praesidio (Novato) 1993
Smith, Michael Station X: The Codebreakers of Bletchley Park. Macmillan 1998
Welchman, Gordon The Hut Six Story: Breaking the Enigma Codes. McGraw Hill 1982
Winterbotham, F.W. The Ultra Secret. Weidenfeld and Nicolson 1973
West, Nigel GCHQ: The Secret Wireless War 1900-86. Weidenfeld and Nicolson 1986
ibid MI6: British Secret Intelligence Service Operations 1909-45. Weidenfeld and Nicolson 1973
Wright, Peter Spycatcher. Heinemann (Sydney) 1988
Documentary sources:
1. National Archives, Kew. HW1 series GC&CS Churchill files. HW3 series GC&CS official histories and personal memoirs. HW14 series GC&CS correspondence files.
2. National Archives, Washington
3. DENN 1-6 at Churchill College, Cambridge
The quotations from HW3 & 14 and the McCormack report in chapter 8 are published by permi
ssion and/or under the freedom of information act. Churchill College Cambridge hold the originals of chapters 2,3,4 and 7 and are out of copyright.
AGD and son Robin with golf clubs, 1936
A transcription of the Zimmerman telegram in 1917. Intercepted by British codebreakers, it was instrumental in persuading the USA to declare war on Germany.
Signal to the Director of the Iintelligence Division of the Naval Staff from M.I.1.B., July 13 1917
(Back row) AGD’s father and mother-in-law. Between them, the author’s mother and (centre) the author. On the right (back) AGD’s mother, AGD and daughter ‘Y’ in 1931.
AGD’s family outside their home at 48 Tedworth Square, London, 1936
AGD’s wartime passport photograph
AGD (left) with Professor E.R.P. Vincent, one of the Hut 4 Italian experts (centre), and Colonel John Tiltman, the brilliant codebreaker.
Thirty Secret Years Page 19