Churchill's Secret War Read online

  CHURCHILL’S SECRET WAR

  In memory of

  Alastair Guthrie Denniston

  1881–1961

  CHURCHILL’S SECRET WAR

  Diplomatic Decrypts, the Foreign Office and Turkey 1942-44

  ROBIN DENNISTON

  Cover picture: Winston Churchill and President Ismet Inönü at the

  Anglo-Turkish Summit, 1943 (IWM K3989)

  First published 1997

  This edition first published 2009

  The History Press

  The Mill, Brimscombe Port

  Stroud, Gloucestershire, GL5 2QG

  www.thehistorypress.co.uk

  This ebook edition first published in 2016

  All rights reserved

  © Robin Denniston, 1997, 1999, 2009

  The right of Robin Denniston to be identified as the Author

  of this work has been asserted in accordance with the

  Copyrights, Designs and Patents Act 1988.

  This ebook is copyright material and must not be copied, reproduced, transferred, distributed, leased, licensed or publicly performed or used in any way except as specifically permitted in writing by the publishers, as allowed under the terms and conditions under which it was purchased or as strictly permitted by applicable copyright law. Any unauthorised distribution or use of this text may be a direct infringement of the author’s and publisher’s rights, and those responsible may be liable in law accordingly.

  EPUB ISBN 978 0 7509 7955 9

  Typesetting and origination by The History Press

  eBook converted by Geethik Technologies

  CONTENTS

  List of Plates

  Author’s Note

  Acronyms and Abbreviations

  Introduction

  1 Why Turkey?

  2 Churchill’s Diplomatic Intercepts

  3 Before the Deluge: 1940–41

  4 Turkish Neutrality: Liability or Asset?

  5 Churchill’s Turkey Hand 1942

  6 Adana and After

  7 Churchill’s ‘Island Prizes Lost’ Revisited

  8 Cicero, Dulles and Philby: 1943–44

  9 Conclusions

  Appendices

  Notes

  Bibliography

  LIST OF PLATES

  1 Churchill and Inönü, 1943

  2 Oshima intercepted: BJ

  3 A classical cryptographer, 1934

  4 Roosevelt, Inönü, Churchill, 1943

  5 Churchill in Cairo, 1943

  6 Churchill on Turkish soil, 1943

  7 Oshima and Hitler, 1939

  8 Rommel and Mussolini, 1944

  9 Knatchbull-Hugessen and Churchill, 1943

  10 Anglo-Turkish Summit, 1943

  AUTHOR’S NOTE

  Churchill’s interest in secret signals intelligence (sigint) is now common knowledge, but his use of intercepted diplomatic telegrams (BJs) in the Second World War has only become apparent with the release in 1994 of his regular supply of Ultra, the DIR/C Archive. Churchill proves to have been a voracious reader of diplomatic intercepts from 1941–44, and used them as part of his communication with the Foreign Office.

  This book establishes the value of these intercepts (particularly those Turkey-sourced) in supplying Churchill and the Foreign Office with authentic information on neutrals’ response to the war in Europe, and analyses the way Churchill used them. Turkey was seen by both sides to be the most important neutral power.

  Why did Turkey interest Churchill? This book answers the question by tracing his involvement with diplomatic intercepts back to 1914, and then revealing how the Government Code and Cipher School (GCCS) was empowered to continue monitoring such traffic until 1939, when ‘Station X’ was established at Bletchley Park (BP).

  After tracing the interwar work of GCCS on the secret diplomatic traffic of most major powers and outlining Turkey’s place among those powers, Robin Denniston concentrates on four events or processes in which Churchill’s use of diplomatic messages played a part in determining his wartime policy, which was sometimes at odds with that of the Foreign Office. He examines the use Churchill and the Foreign Office made of BJs to persuade Turkey to join the Allies between 1940 and 1943, suggesting that the Adana Conference of January 1943 produced little change in Turkish foreign policy partly because of the lack of BJs, due to tight British security on the train. The Dodecanese defeat of 1943 is explained in the light of the signals intelligence Churchill was reading. A later chapter shows the results at GCCS in London of the theft of secret Foreign Office papers in Ankara from November 1943: whether actual BJs were included in these papers, how they were received and how they led to a breakthrough in reading the German diplomatic cipher, too late to be useful to Churchill.

  Acronyms and Abbreviations

  ADM

  Admiralty

  AM

  Air Ministry

  BJ

  Secret signals intercept circulated in Whitehall in blue jackets

  BP

  Bletchley Park

  BSC

  British Security Co-ordination

  ‘C’

  Gen Sir Stewart Menzies, Head of the Secret Intelligence Services

  C&W

  Cable & Wireless

  C-in-C

  Commander-in-Chief

  CCC

  Churchill College, Cambridge

  CIGS

  Chief of the Imperial General Staff (Lord Alanbrooke)

  COS

  The (British) Chiefs of Staff

  DEFE

  Files of the Minister of Defence (Churchill) at the PRO

  Dedip

  Foreign Diplomatic Decrypts, accepted usage from 1943

  DF

  Direction Finding

  DGFP

  Documents on German Foreign Policy – see Bibliography

  DIR/C

  The files brought by the Chief of the British Secret Service to Churchill. Called HW1 in the PRO.

  DMI

  Director of Military Intelligence

  DNI

  Director of Naval Intelligence

  FO

  The (British) Foreign Office

  GCCS

  The Government Code and Cipher School

  GCHQ

  Government Communications Headquarters

  GHQ

  General Headquarters

  GPO

  General Post Office

  IWM

  The Imperial War Museum

  JIC

  Joint Intelligence Committee

  ME

  Middle East

  MEW

  Ministry of Economic Warfare

  MI

  1B Military Intelligence (Cryptanalytical Section)

  MI6

  Secret Intelligence Service (MI6)

  MTB

  Motor Torpedo Boat

  NAC

  National Archives of Canada in Ottawa

  NSA

  National Security Agency (USA)

  OTP

  One Time Pad: an unbreakable code system employing pages of 5-figure numbers available only to sender and recipient

  PRO

  Public Record Office

  RAF

  Royal Air Force

  SD

  Sicherheitsdienst: the Intelligence Branch of the SS under Heydrich.

  sigint

  signals intelligence

  SIS

  Secret Intelligence Service (MI6)

  sit rep

  situation report

  TA

  Traffic Analysis

  W/T

  Wireless Telegraphy

  Introduction

  Whence did WSC get his more outrageous strategic ideas . . .? The answer is strictly and absolutely f
rom his own brain.

  Desmond Morton, 9 July 1960

  The literature on Churchill’s use of secret intelligence at war is large and growing, in the USA as well as the UK. This book studies his use of diplomatic intercepts, based on newly discovered files Churchill himself hoarded during his lifetime. These files – which came to him almost daily from his intelligence chief, Brig Stewart Menzies – contain a surprise, in that together with much Ultra traffic (high-grade or Enigma/Fish intercepts frequently referred to as ‘Boniface’) there was much more diplomatic material in what Churchill was reading than any historian has hitherto realised. It was widely recognised, of course, that he studied the military, naval and air intercepts supplied to him from 1941. But it has only recently become apparent that Churchill’s absorption in the product of the government’s deciphering department had its origins in the First World War. In November 1914, when First Lord of the Admiralty, he had written the original charter for the legendary ‘Room 40 OB’, ensuring that German naval intercepts were available to his nominees. This involvement with, and possessiveness over, secret signals intelligence continued unabated until 1945 when Japanese diplomatic messages between Berlin and Tokyo informed the war leadership that the time had come to drop atomic bombs on Hiroshima and Nagasaki. The intercepted telegrams he studied were diplomatic as often as army and navy traffic in and between both world wars.

  Churchill had always been interested in Turkey, ever since intercepts supplied to him by the Director of Naval Intelligence, Adm Reginald Hall, told him he could have secured Turkish non-participation in hostilities in February 1915 and he chose to disregard this vital information. Later he backed a Greek foray against the Turks at Smyrna in 1922 in an episode in which intercepted diplomatic messages between the Turkish ambassador in Paris and Constantinople provided him, Curzon and Lloyd George with vital information on the attitude of the Turkish leadership. By 1940 he had convinced himself that he alone could bring Turkey into the war as an ally. Few people, then or now, agreed with him, but he took immense pains to develop British policy towards Turkey in a manner that would shorten the war.

  Why was Churchill so interested in Turkey? He believed that Turkey, like the other major neutral powers, collectively and individually, had the opportunity to affect the outcome of the war. Turkey was the most powerful neutral, for historical and geographical as well as strategic reasons. So Turkey could help to determine which way the war would go. Other questions then follow: what effect did Churchill’s interest have on Turkey’s determination to stay neutral in the Second World War? By what means did Turkey exploit the international situation to safeguard its own sovereignty? In Whitehall, how did the policies of the Foreign Office and the War Office differ from Churchill’s own policy in playing ‘the Turkey hand’? And within the Foreign Office whose voice counted for most, and did the diplomats there speak with one voice? How did the government obtain authentic and timely knowledge of Turkish intentions? How did the diplomatic intercepts produced in London and Bletchley between 1922 and 1944 alter the course of British foreign policy in the eastern Mediterranean, and what use was made of them by the Foreign Office and Churchill?

  In considering these and related questions, this book focuses on three specific events – the conference in January 1943 between Churchill and the Turkish leadership; the abortive British campaign to recapture the Dodecanese later that year, with its diplomatic consequences; and one of the single most spectacular spy coups of the war, the so-called ‘Cicero’ affair, on which new light is thrown by reference to Churchill’s files of diplomatic intercepts in November 1943. All these events are seen against a background of international diplomatic intrigue in which Turkey’s determination to stay neutral plays a central role.

  The PRO has provided access (except where documents have been withheld by GCHQ) to files Churchill valued so highly that their contents had often to be reciphered and cabled to him – sometimes in the exact words (ipsissima verba) – whenever he was out of the country. Their recent arrival at the PRO means that diplomatic historians have had no more than a few months to review the material and undertake the dangerous counterfactual exercise of answering the question, how would Churchill and the Foreign Office have handled Turkey without the Turkey-sourced intercepts? An attempt is made here to strip out these messages from the general progress of Turco-British relations to see how differently Churchill would have played the Turkey hand had this material not been available to him, in its ipsissima verba state, in DIR/C.1

  Little attention has hitherto been given to the British government’s achievements in obtaining intelligence by intercepting letters and telegrams and by breaking the diplomatic ciphers of neutral and friendly nations, and its impact on the conduct of foreign policy during the Second World War. Such references as there are to the non-military side of the wartime secret intelligence have been made despite the fact that both the US State Department and Her Majesty’s government have been unwilling until recently to disclose any diplomatic material. The arrival of DIR/C in the PRO means that a new source of secret information available throughout much of the war to the Foreign Office but hitherto unknown to most historians of secret intelligence can now be studied at least for part of the period during which Turco-British relations were a major concern of British foreign policy. This also raises questions related to the Foreign Office’s perception of the Turkish mind which require answering.

  I suggest that the intelligent reading and use of secret signals intercepts, in war and peace, by the major western powers, assisted foreign policy makers (notably Churchill) who understood their limitations as well as their potential value. But the corollary that diplomatic history might need to be substantially rewritten in the light of recent releases in London, Ottawa and Washington does not necessarily follow. Little now known from the released intercepts, and unknown or only partially known before, actually affects existing diplomatic history.

  Turkey was a crucial case. The Foreign Office had been hard at work improving Anglo-Turkish relations since the early 1930s, but by 1940 this was reduced to Turkey’s trade in chrome with Britain and with Germany. Without Churchill relentlessly seeking any opportunity to divert German armies from the Eastern Front and looking for an ally in the eastern Mediterranean, it is unlikely that Turkey would have loomed so large in Allied war strategy. At least two policies, therefore, towards Turkish neutrality in the Second World War can be discerned: those of Churchill and of the Southern Department of the Foreign Office which was responsible for Turkey. What united them was their common reading of Turkey-related diplomatic decrypts.

  Within the Southern Department, the wartime minutes of George Clutton and John Sterndale-Bennett (nicknamed ‘Benito’ after Mussolini) predominate, but the observations of very senior diplomats such as the Deputy Under Secretary, Orme Sargent (‘Moley’) and the Permanent Under Secretary, Sir Alexander Cadogan, throw light on the different perceptions of Turkish neutrality within the government. The Foreign Secretary, Anthony Eden, himself played a part, marred by his too obvious concern with the consequences to his own political career of the success or otherwise of British Turkish policy. From Ankara the British ambassador, Sir Hughe Knatchbull-Hugessen, wrote informally about Turkish affairs to both Sargent and Cadogan. John Sterndale-Bennett and another even abler colleague, Knox Helm, were posted to the embassy in Ankara, thus ensuring co-ordination of policy between Ankara and London. This relationship can be traced by studying the FO 371 (general correspondence) and FO 195 (embassy and consulate) files of the period. While this book concentrates on DIR/C, these and other Foreign Office files have also been useful. There are drafts of Churchill’s unsent letters to colleagues and to Roosevelt, relating to Turkey, in the PREM3 and 4 (Premier) files. Some War Office, Admiralty and Air Ministry files contain references to decrypt diplomacy which the ‘weeders’ have missed.

  That a new theme in Churchillian historiography has thus emerged is due to the release of DIR/C. The evidence therein points u
p Churchill’s enthusiasm for playing the Turkey hand alone and demonstrates his personally directed policy towards Turkey, despite this being the responsibility of the Southern Department under the Secretary of State. This book includes an attempt to assess:

  • The importance to the Department of the diplomatic intercepts as distinct from other sources of information.

  • How officials regarded and used them.

  • How their advice, consequent on these questions, was received and adopted or otherwise by the framers of British foreign policy in the eastern Mediterranean throughout the war.

  This study of Churchill’s use of secret signals intelligence, before and during the Second World War, breaks new ground in several other respects. The role of the neutrals has never received much attention from historians.2 In focusing on Turkey’s remarkably resilient and subtle diplomacy towards Italy, Germany, Britain and, especially, the Soviet Union throughout the war, several significant themes develop. One theme is the alternating strategies of Germany and Britain towards the Balkans – the former involving an invasion of Turkey from Bulgaria to carry the Blitzkrieg to Egypt and Persia in 1940–41, the latter the opening of a second front in the Balkans from Turkey across the eastern Mediterranean in 1943, to divert German divisions from the Eastern Front and thus hasten D-Day in the west. Another is the predominating voice of Churchill in Allied war planning in the eastern Mediterranean. Since he was neither a commander-in-chief nor a head of state (as Roosevelt and Stalin were) his strategic ambitions could only be promoted through a cumbersome programme involving the Americans, the Russians and his own War Cabinet and Chiefs of Staff. Despite these handicaps, Churchill struggled with his allies and colleagues for what he saw as the best way forward from 1941, and Turkish involvement in the war was always on his agenda.