The Black Door: Spies, Secret Intelligence and British Prime Ministers. Richard Aldrich
the spring of 1944, plans for D-Day finally connected Churchill with MI5 and deception in detail. On Wednesday, 8 March, Menzies joined Churchill, Eden and the chiefs of staff at a special meeting at Downing Street to discuss ‘certain aspects’ of the D-Day preparations that could not be revealed even to the war cabinet. They went backwards and forwards over the deception plans, especially the vast dummy works, supply depots and aerodromes that were being built to misdirect Hitler about the direction of the assault and to persuade him to place his reserves in the wrong location. The conundrum was whether to ban the diplomats of neutral countries based in London from using enciphered messages to report home. The Spanish had passed a great deal of material to the Germans by this means, while the Swedish air attaché had been especially active in spying for the Nazis. Yet Menzies was against a ban. Two years previously, during the invasion of North Africa, the vast volume of conflicting information emanating from Britain through these channels had actually ‘misled the enemy’, and German intelligence officers in Spain had proved delightfully incompetent at sifting ‘true from false information’. Unintentionally, the reports of various spies had also ‘helped us greatly’ in building up aspects of the cover plan and knowing what to stress. Menzies was confident, and rather relishing the deception battle ahead.10
As D-Day approached, the prime minister was increasingly obsessed with the plans and the accompanying cover operations. Again, senior MI5 officers were concerned that he might take some rash initiative of his own. But some activities were high-risk, and required Downing Street’s approval. Thus, at ten in the morning on 15 April 1944, Colonel Bevan of the London Controlling Section, the secret unit charged with coordinating deception plans, arrived at 10 Downing Street. Churchill was sitting in his pyjamas smoking a cigar and reading boxes of secret papers. Bevan had come seeking his personal permission to execute one of the most ingenious deception operations of the Second World War: ‘Operation Mincemeat’. The deception planners wished to create a fictitious ‘Major William Martin’ of the Royal Marines, supposedly on the staff of Vice Admiral Lord Louis Mountbatten, Chief of Combined Operations. They would eventually use the body of a homeless Welshman, Glyndwr Michael, who had died after swallowing rat poison, and which had been purchased from a hospital morgue for £10. Dressed in the appropriate uniform, and with minute attention to detail, the corpse was to have a briefcase chained to its wrist containing top-secret plans that suggested the main Allied attack would come through the Mediterranean. Churchill was thrilled, and with his enthusiastic blessing ‘Operation Mincemeat’ went ahead.11
Two weeks later the body was dropped into the sea on an incoming tide. Spanish officials recovered it and, very properly, handed it over to the British authorities. But first they opened the briefcase, photographed the documents and handed the evidence to German intelligence. The outline plan carried by ‘Major Martin’ pointed to an Allied attack through Greece and the Balkans in an operation codenamed ‘Husky’. The fact that the Germans swallowed the bait was later revealed in Ultra decrypts.12 Churchill took great satisfaction in further intercepts showing that Hitler had bought the broader deception plan completely.
Sitting with Menzies at Chequers, Churchill gestured in the direction of his cat, ‘Nelson’, who was looking intently out of the window. He remarked that the cat was ‘in touch with the pelicans on the lake’, adding, ‘and they’re communicating our information to the German secret service!’13 One of the prime minister’s perpetual arguments with Menzies was about the extent to which Ultra should be exploited, or protected. He cared deeply about its security, but also directly exploited it on occasion. During the battle of El Alamein in October 1942, for example, GC&CS informed Churchill of an intercept reassuring Rommel that a convoy of Italian ships was on its way with fresh ammunition and fuel. Hesitating for only a moment, Churchill ordered an attack on the convoy. Rommel’s deep suspicions about the security of Enigma were only alleviated when the British sent a deliberately insecure message congratulating a group of fictional Italian agents on their information and for their help in sinking the convoy. Ultra later revealed that the Germans had intercepted the signal and set off in hot pursuit of the fictional Italians.14
Upon hearing about Axis successes against British communications during 1943, Churchill demanded an immediate inquiry into the security of British ciphers.15 As the Allies made their way through Italy and France they rounded up Axis codebreakers, and were shocked to find that many British embassies had been penetrated. Although the Italians had not attacked Britain’s top-grade cipher machine, the Typex, they had broken many other systems. Bletchley Park boffins held prolonged ‘conversations’ with Commander Cianchi, head of the Italian Cryptographic Bureau in Rome, and his staff. Cianchi enthusiastically set out the triumphs of the Italians, especially against British Admiralty communications. The catastrophic Dieppe raid of August 1942 had gone badly because the Germans had been reading Royal Navy messages and had seven days’ warning of this ‘surprise’ attack. Convoy message security had also been weak. The findings of the inquiry did not make for comfortable reading, leaving Churchill at his explosive best. He insisted on the immediate creation of a new body, the Cypher Security Board, to underline the importance he attached to this subject. Soon it had extended its authority over the design, production and operation of all British cipher machines, most of which were made at Bletchley Park’s outstations or at a secret Foreign Office factory at Chester Road in Borehamwood. Ten years later, this had developed into the London Communications Security Agency, a hidden fourth British secret service that worked alongside MI5, MI6 and GCHQ and managed some of the UK’s most sensitive projects.16
Churchill was less bothered about his personal security than about ciphers. Yet MI5 learned of more than a dozen attempts on his life during the war. Some of them were bizarre or childish, including an attempt in May 1943 to kill him or members of his entourage using exploding chocolate positioned among the snacks laid out for the war cabinet. This plot was uncovered by Lord (Victor) Rothschild, MI5’s bomb disposal expert. It was not the only such attempt scuppered by Rothschild, and Churchill personally insisted on his decoration.17
Germany launched numerous attempts to kill Churchill, many of which were more serious. In late May 1943, Menzies received information from Bletchley Park that it had decoded a most alarming message from a German secret service agent in the Spanish port of Algeciras. The agent had observed the arrival of Churchill and de Gaulle by air, and noted that they had headed eastwards. Churchill was travelling to see General Eisenhower in Algiers to make a passionate case for the invasion of Italy and Sicily. He was joined by Eden, General Montgomery and the chiefs of staff. Menzies rightly feared an attempt to eliminate Churchill on his return. The fact that the secret German watchers were themselves being watched protected Churchill. But events unfolded more quickly than Menzies had expected.18
On 1 June, BOAC’s flight 777 took off from Lisbon at 9.35 a.m. and headed towards the Bay of Biscay. Nazi spies were convinced that Churchill was on board. In fact, among the passengers was a man called Alfred Tregar Chenhalls, who unfortunately for himself resembled Churchill, dressed like him and even smoked large cigars. It was clear that the Nazis believed Chenhalls was the prime minister. In fact, he was the business manager of the film star Leslie Howard, who was travelling with him. Three hours after take-off an entire squadron of German warplanes attacked the aircraft. Punctured by shells and bullets, it plummeted into the sea, killing all on board. The attacking aircraft circled the flaming wreckage, and their crew took pictures that were sent to Berlin. Three days later the New York Times reported: ‘It was believed in London that the Nazi raiders had attacked on the outside chance that Winston Churchill might have been among the passengers.’ Churchill too subscribed to the mistaken-identity thesis, and referred to Leslie Howard’s death – which was a severe blow to British morale – as ‘one of the inscrutable workings of fate’. Despite rumours to the contrary, it is overwhelmingly likely that the shooting down of the plane was merely an unfortunate coincidence,