The Secret History of MI6 - Keith Jeffery [129]
The arrangement whereby the Chief of SIS was simultaneously Director of the Government Code and Cypher School lasted for more than twenty years. Although the armed services kept some residual expertise in the field, SIS effectively acquired monopoly control over British signals intelligence, a fact which was to prove extremely important in the future. This branch of the British intelligence community was notably successful. John Ferris has estimated that ‘the GC&CS was one of the world’s largest code-breaking agencies, perhaps the biggest; as effective as any other, better than most, possibly the best on earth between 1919 and 1935’. It provided Whitehall with a steady stream of intercepted and decrypted telegrams of foreign governments. It had sustained success throughout the interwar years against French, United States and Japanese traffic, and that of many smaller powers. Up to 1930 or so, it also had ‘near mastery’ of Italian diplomatic systems. It was less successful against Soviet traffic in Europe, especially from late 1920, though it continued to be able to read a fair proportion of Asian material. Germany, a low priority in the 1920s, was a blind spot, and continued to be so in the 1930s, though success against Japanese traffic helped illuminate British understanding of the forces behind the German-Japanese-Italian Anti-Comintern Pact of 1936-7.9
From the beginning of his time as Chief, as well as stiffening up the Service’s internal organisation, Sinclair sought to expand its reach over the British intelligence community as a whole. At the end of 1923 he told Crowe at the Foreign Office that he wanted ‘to undertake a certain re-organisation of this Service, which should be more efficient, and what is more important, should provide a basis for a war organisation’.10 Archival evidence from the start of 1924 confirms that, on the Circulation side, the Political Section V had become Section I (in place of the defunct Economic Section) and the geographically arranged Production sections had been concentrated into four groupings: G.1 (the Baltic Group), G.2 (Scandinavian Group), G.3-5 (Western and Central Europe Groups), and G.6-7 (Near and Far Eastern Groups). There was no indication of any provision for the envisaged North and South American Groups. Within six months G.1 and G.2 had been amalgamated.
In January 1924, too, Sinclair held a meeting with the head of the Code and Cypher School confirming the integration of its work with that of SIS. It was ‘accepted that G.C. & C.S. was responsible for cryptography, and S.I.S. for the distribution of intelligence derived from this source as well as supplying intelligence and criticism to G.C. & C.S. to assist cryptography’. Section I of SIS was to ‘supply G.C. & C.S. with list of general subjects on which to concentrate . . . Armed Forces Sections of S.I.S. to collaborate’. The Code and Cypher School, moreover, was to ‘have full access to S.I.S. records’. By June 1924, however, and perhaps reflecting the considerable volume of intercept material produced, GC&CS was instructed to distribute decrypts directly to its customer departments, though copies of all material were also to be sent to Sinclair. There were some practical difficulties with this, since the two organisations were located