The first requirement for successful use of secret data is that commanders should be willing to analyse it honestly. Herbert Meyer, a veteran of Washington’s National Intelligence Council, defined his business as the presentation of ‘organized information’; he argued that ideally intelligence departments should provide a service for commanders resembling that of ship and aircraft navigation systems. Donald McLachlan, a British naval practitioner, observed: ‘Intelligence has much in common with scholarship, and the standards which are demanded in scholarship are those which should be applied to intelligence.’ After the war, the surviving German commanders blamed all their intelligence failures on Hitler’s refusal to countenance objective assessment of evidence. Signals supremo Albert Praun said: ‘Unfortunately … throughout the war Hitler … showed a lack of confidence in communications intelligence, especially if the reports were unfavourable [to his own views].’
Good news for the Axis cause – for instance, interceptions revealing heavy Allied losses – were given the highest priority for transmission to Berlin, because the Führer welcomed them. Meanwhile bad tidings received short shrift. Before the June 1941 invasion of Russia, Gen. Georg Thomas of the WiRuAmt – the Wehrmacht’s economics department – produced estimates of Soviet weapons production which approached the reality, though still short of it, and argued that the loss of European Russia would not necessarily precipitate the collapse of Stalin’s industrial base. Hitler dismissed Thomas’s numbers out of hand, because he could not reconcile their magnitude with his contempt for all things Slavonic. Field-Marshal Wilhelm Keitel eventually instructed the WiRuAmt to stop submitting intelligence that might upset the Führer.
The war effort of the Western democracies profited immensely from the relative openness of their societies and governance. Churchill sometimes indulged spasms of anger towards those around him who voiced unwelcome views, but a remarkably open debate was sustained in the Allied corridors of power, including most military headquarters. Gen. Sir Bernard Montgomery was a considerable tyrant, but those whom he trusted – including his intelligence chief Brigadier Bill Williams, a peacetime Oxford don – could speak their minds. All the United States’s brilliant intelligence successes were gained through codebreaking, and were exploited most dramatically in the Pacific naval war. American ground commanders seldom showed much interest in using their knowledge to promote deceptions, as did the British. D-Day in 1944 was the only operation for which the Americans cooperated wholeheartedly on a deception plan. Even then the British were prime movers, while the Americans merely acquiesced – for instance, by allowing Gen. George Patton to masquerade as commander of the fictitious American First US Army Group supposedly destined to land in the Pas de Calais. Some senior Americans were suspicious of the British enthusiasm for misleading the enemy, which they regarded as reflecting their ally’s enthusiasm for employing guile to escape hard fighting, the real business of war.
GC&CS, the so-called Government Code and Cipher School at Bletchley Park, was of course not merely the most important intelligence hub of the conflict, but from 1942 Britain’s outstanding contribution to victory. Folk legend holds that Alan Turing’s creation of electro-mechanical bombes exposed Germany’s entire communications system to Allied eyes by breaking the Enigma’s traffic. The truth is far more complex. The Germans employed dozens of different keys, many of which were read only intermittently, often out of ‘real time’ – meaning insufficiently rapidly to make possible an operational response – and a few not at all. The British accessed some immensely valuable Enigma material, but coverage was never remotely comprehensive, and was especially weak on army traffic. Moreover, an ever-increasing volume of the Germans’ most secret signals was transmitted through a teleprinter network which employed an entirely different encryption system from that used by Enigma. The achievement of Bletchley’s mathematicians and linguists in cracking the Lorenz Schlüsselzusatz was quite distinct from, and more difficult than, breaking the Enigma, even though recipients in the field knew the products of all such activities simply as ‘Ultra’.* Bill Tutte, the young Cambridge mathematician who made the critical initial discoveries, is scarcely known to posterity, yet deserves to be almost as celebrated as Turing.
Ultra enabled the Allied leadership to plan its campaigns and operations in the second half of the war with a confidence vouchsafed to no previous warlords in history. Knowing the enemy’s hand did not diminish its strength, however. In 1941 and into 1942, again and again the British learned where the Axis intended to strike – as in Crete, North Africa and Malaya – but this did not save them from losing the subsequent battles. Hard power, whether on land or at sea or in the air, was indispensable to the exploitation of secret knowledge. So, too, was wisdom on the part of British and American commanders and their staffs – which proved conspicuously lacking at key moments during the 1944–45 north-west Europe campaign. Intelligence did, however, contribute importantly to mitigating some early disasters: young R.V. Jones’s achievement in showing the path towards jamming the Luftwaffe’s navigational beams significantly diminished the pain inflicted by the Blitz on Britain. At sea, Ultra’s pinpointing of German U-boats – with an alarming nine-month interruption in 1942 – made it possible to reroute convoys to evade them, an even more important contribution to holding open the Atlantic supply line than sinking enemy submarines.
The Americans had some reason to suspect their allies of romanticism about deception. Col. Dudley Clarke – famous not least to Spanish police, who once arrested him wearing woman’s clothes in a Madrid street – conducted a massive cover operation in the North African desert before the October 1942 Battle of El Alamein. Historians have celebrated Clarke’s ingenuity in creating fictional forces which caused Rommel to deploy significant strength well south of the focal point of Montgomery’s assault. However, such guile did not spare Eighth Army from the fortnight of hard fighting that proved necessary to break through the Afrika Korps. The Germans argued that Clarke’s activities changed nothing in the end, because they had time to redeploy northwards before the decisive British assault. In Burma Col. Peter Fleming, brother of the creator of James Bond, went to elaborate and hazardous lengths to leave a haversack full of deceptive ‘secret papers’ in a wrecked jeep where the enemy were bound to find it, but the Japanese took no notice of this haul when they got it. From 1942 onwards, British intelligence achieved an almost complete understanding of Germany’s air defences and the electronic technologies they employed, but Allied bomber forces continued to suffer punitive casualties, especially before US long-range fighters wrecked the Luftwaffe in the air in the spring of 1944.
Whatever the contribution of British tactical deceptions in North Africa, Allied deceivers had two important and almost indisputable strategic successes. In 1943–44, Operation ‘Zeppelin’ created a fictitious British army in Egypt which induced Hitler to maintain large forces in Yugoslavia and Greece to repel an Allied Balkan landing. It was this imaginary threat, not Tito’s guerrillas, that caused twenty-two Axis divisions to kick their heels in the south-east until after D-Day. The second achievement was, of course, that of Operation ‘Fortitude’ before and after the assault on Normandy. It bears emphasis that neither could have exercised such influence had not the Allies possessed sufficient hard power, together with command of the sea, to make it credible that they might land armies almost anywhere.
Some Russian deceptions dwarf those of the British and Americans. The story of agent ‘Max’, and the vast operation launched as a diversion from the Stalingrad offensive, at a cost of 70,000 Russian lives, is one of the most astonishing of the war, and almost unknown to Western readers. In 1943–44, other Soviet ruses prompted the Germans repeatedly to concentrate their forces in the wrong places in advance of onslaughts by the Red Army. Air superiority was an essential prerequisite, in the East as in the West: the ambitious deceptions of the later war years were possible only because the Germans could not carry out photographic reconnaissance to disprove the ‘legends’ they