The Secret History of MI6 - Keith Jeffery [178]
Over the spring of 1939 Dunderdale began to work with the French on arrangements for mobilisation in the event of war with Germany or Italy, and he got Menzies to invite Rivet to London for informal discussions regarding arrangements should a British Expeditionary Force again be deployed in France. During their visit (in early June), Rivet, Captain Henri Navarre (of the German Section of the Service de Renseignements) and Commandant Brun (their mobilisation officer) were given red-carpet treatment, being put up at the Dorchester Hotel and dined at the Savoy, as well as having discussions with Menzies, Hubert Hatton-Hall (of the Army Section) and Rex Howard. With the scale and intensity of Anglo-French co-operation stepping up markedly over the summer of 1939, Sinclair worried about the burden Dunderdale was carrying. While recognising that he was the principal link with the French, Sinclair felt it was ‘impossible’ for him ‘to carry out all aspects of this liaison contact’ without interfering with his ‘most important work’, which was obtaining intelligence. Sinclair therefore told Dunderdale to confine himself to work connected with agents, ‘agent doubles’ and French General Staff duties, while the head of station (now Major Geoffrey W. Courtney, who had replaced Jeffes in late 1937) would deal with counter-espionage, field security, censorship, passports ‘and any kindred matters’.
One cost of the burgeoning Anglo-French intelligence relationship was an increasing British reliance on what turned out to be inflated French estimates of German strength and capabilities. Douglas Porch has argued that the Deuxième Bureau’s low status and limited budget had ‘serious consequences on the quality of intelligence passed on to the high command . . . Annoyed that their message was not striking home, intelligence officers raised the tone of their reports, [and] exaggerated the numbers of German soldiers, tanks and aircraft.’ Lieutenant Colonel Kenneth Strong, who had been assistant military attaché in Berlin until the outbreak of war and then served in the Military Intelligence German Section in the War Office, recalled that French estimates were sometimes 20 per cent higher than British figures. This phenomenon continued into 1940, when (according to F. H. Hinsley) it ‘led Whitehall into over-estimating the total number of German divisions’, though this, he asserted, ‘had no unfortunate strategic consequences’.10
Of all Dunderdale’s French liaisons built up during the 1930s, the most important turned out to be that with Captain Gustave Bertrand, head of the French cryptanalytical department, the Section des Examens. Between 1931 and 1938 an exceptionally valuable French spy in the communications section of the German army, Hans-Thilo Schmidt (known as ‘Asché’) supplied information about the Enigma cypher machine. Bertrand passed some of this material to the Poles and the British, helping the former both to build replicas of the machine and to decrypt some Enigma traffic from 1933 until December 1938, when the Germans introduced improvements. By Hinsley’s account, the British initially ‘showed no great interest in collaborating’ with the French (or, indeed, the Poles).11 By the autumn of 1938, however, the situation had changed significantly and at the start of October Commander Alastair Denniston, the head of the Government Code and Cypher School (GC&CS), told Sinclair that documents supplied by Bertrand were ‘of assistance to our researches on the Enigma machine’. Indeed, Captain Tiltman of GC&CS’s Military Section described the documents as ‘of first importance and the saving of time and