They offered him several alarming examples of bottlenecks and hold-ups. One concerned the decoding of German Army and Air Force Enigma in Hut 6, which was especially close to Churchill’s heart, given his obsession with Rommel and developments in the Western Desert:
We are intercepting quite a substantial proportion of wireless traffic in the Middle East which cannot be picked up by our intercepting stations here. This contains among other things a good deal of new ‘Light blue’ intelligence. Owing to shortage of trained typists, however, and the fatigue of our present decoding staff, we cannot get all this traffic decoded. This has been the state of affairs since May. Yet all that we need to put matters right is about twenty trained typists.50
Churchill was apoplectic. The result was one of his famous messages headed ‘Action This Day’. He insisted that Bletchley Park’s needs be met in full, and with extreme priority. As a result, throughout 1941 the British were able to read all German air and army intercepts in collaboration with an American liaison group working at Bletchley Park. The Americans had not made headway with Enigma, but had achieved an equivalent triumph against Japanese diplomatic ciphers. Thus, during the summer of 1941 the British were also reading the secrets of Germany’s Japanese allies, including the vital messages of Baron Ōshima, the Japanese ambassador in Berlin, to whom Hitler liked to talk at length, and who was regarded as his Japanese confidant.51
In October 1941, Churchill and Roosevelt held a top-secret meeting off Newfoundland on board the US Navy ship the USS Augusta to discuss military matters, including America’s then top-secret assistance to the British fight against Germany. On his way to the meeting, Churchill made special arrangements for Ultra to reach him ‘in a weighted case, so that they will sink in the sea if anything happens to the plane’.52 A few weeks later, British codebreakers intercepted a communiqué from the Japanese embassy in London to Tokyo with a remarkably detailed account of the secret meeting. The news stunned Churchill. Even worse, it transpired that one of those who passed the information to the Japanese was not only a highly regarded member of the House of Lords, but a long-time Churchill associate.
In 1919 William Forbes-Sempill, a pioneering commander in the Royal Flying Corps whose father had been an aide to King George V, led a mission to Japan – then a British ally – to help it develop naval air power. When Britain terminated the alliance with Japan in the 1920s, Sempill secretly continued assisting Tokyo, providing it with the designs of the latest engines, bombs and aircraft carriers. He also encouraged the development of Japanese naval air power as a national strategy. In 1924, MI5 had begun watching Sempill and intercepting his correspondence, but it hesitated to act because of his status as a war hero at the heart of the British aristocracy. By the mid-1930s, Sempill had become a member of the House of Lords, and joined a number of British pro-Nazi groups. He believed that Britain should have allied with Germany and Japan against Russia and the communists.53
Sempill avoided internment because of his status. He would visit Churchill, and then relay the content of their conversations to the Japanese embassy. When the prime minister realised the severity of the leak in October 1941 he ordered: ‘Clear him out while time remains.’ A few days later, Morton wrote: ‘The First Sea Lord … proposes to offer him a post in the North of Scotland. I have suggested to Lord Swinton that MI5 should be informed in due course so they may take any precautions necessary.’ At one point, the attorney general secretly considered prosecuting Sempill. But when the Admiralty confronted him and pressed for his resignation, Churchill interceded and required only that Sempill be ‘moved’. This is a classic case of the prime minister protecting himself. ‘If Sempill had been revealed as a spy, it would have been politically calamitous for Churchill at a low point in the war.’ Even when he was caught calling the Japanese embassy several times in the week following the attack on Pearl Harbor, Sempill still escaped arrest. After the war, he was decorated by both the Japanese and the British. The latter award was widely regarded as an effort to cover up his activities.54
Towards the end of March 1941, Churchill read one particular Ultra report ‘with relief and excitement’. It showed a major transfer of German armour from Bucharest in Romania to Cracow in southern Poland. ‘To me,’ he recalled, ‘it illuminated the whole Eastern scene like a lightning flash. The sudden movement … could only mean Hitler’s intention to invade Russia in May.’ The armoured units returned to Bucharest, but this, he correctly surmised, simply meant a delay from May to June because of local trouble in the Balkans caused by an SOE-inspired coup. ‘I sent the momentous news at once to Mr Eden.’55
Churchill observed with some satisfaction that it was not until 12 June – only ten days before the attack – that the Joint Intelligence Committee agreed that Hitler had definitely decided to invade Russia. The idea that he would voluntarily begin fighting on a further front when he was already busy in Western Europe and North Africa seemed improbable. The prime minister’s DIY analysis had triumphed on this occasion, and he added jubilantly in his own account: ‘I had not been content with this form of collective wisdom,’ depending instead on Morton’s ‘daily selection of tit-bits, which I always read, thus forming my own opinion, sometimes at much earlier dates’.56
Unsurprisingly, Churchill’s account of the Second World War often portrays him in a favourable light. Yet newly opened archives confirm that he indeed predicted the German attack on Russia before almost anyone else. On 26 March, Ultra showed that Hitler had indeed moved a vast force, including two whole army headquarters, from the Balkans to southern Poland. Only a few days later, Churchill informed Stalin of this directly, disguising the source by hinting that the intelligence came from ‘a trusted agent’. Stalin did not believe Churchill, and neither did the Russian chiefs of staff.57 Frustrated, Churchill repeatedly pressed Stewart Menzies to send Ultra-based material to Moscow in 1941. However, Menzies worried about both the volume of material going to Stalin and its security. He warned Churchill personally and repeatedly not to let the Russians know about Ultra, and to heavily disguise any intelligence as coming from other sources. Menzies knew from reading Ultra that the Russian ciphers were insecure, and anything Churchill told them might well make its way to Berlin.58
Soviet intelligence agents performed brilliantly in early 1941. Secret reports poured in from Germany, Eastern Europe and even Japan, showing in detail Hitler’s massive preparations for invasion. Stalin received more than eighty separate warnings, but ordered his forces to do nothing. The Luftwaffe was permitted to fly reconnaissance missions deep into Soviet territory – some of the aircraft crashed, spilling thousands of feet of film from their underbelly spy cameras. German commando units crossed the Soviet frontier to plan forward routes for the attack. Stalin, however, wanted to signal to Hitler that the Soviet Union was not about to attack Germany, and so avoided mobilisation. He was certain that Hitler would do nothing until he had conquered Britain. This belief was underpinned by an impressive German deception operation that involved two letters to Stalin, directed by Hitler himself. Therefore, Stalin ignored the massive military build-up on his borders, and dismissed every warning of a German attack as disinformation or provocation right up until the morning of 22 June 1941.59
Stalin regarded Churchill’s offer of British intelligence on German troop movements as a crude attempt to entrap him in the war in Europe. For years, London and Moscow had each thought the other was on the verge of a deal with Berlin. Most importantly, for Stalin the dramatic flight to Britain in May 1941 by Rudolf Hess, Hitler’s deputy, was not the erratic act of an unbalanced individual, but firm proof that British talks with Hitler were well advanced. He was obsessed with the idea of a British deal with Hitler, so much so that in October 1944 he was still asking Churchill why British intelligence had brought Hess to Scotland.60 Ironically, Churchill