service officers of all nationalities whose only achievement in foreign postings was to stay alive, at hefty cost to their employers, while collecting information of which not a smidgeon assisted the war effort. Perhaps one-thousandth of 1 per cent of material garnered from secret sources by all the belligerents in World War II contributed to changing battlefield outcomes. Yet that fraction was of such value that warlords grudged not a life nor a pound, rouble, dollar, Reichsmark expended in securing it. Intelligence has always influenced wars, but until the twentieth century commanders could discover their enemies’ motions only through spies and direct observation – counting men, ships, guns. Then came wireless communication, which created rolling new intelligence corn prairies that grew exponentially after 1930, as technology advanced. ‘There has never been anything comparable in any other period of history to the impact of radio,’ wrote the great British scientific intelligence officer Dr R.V. Jones. ‘… It was the product of some of the most imaginative developments that have ever occurred in physics, and it was as near magic as anyone could conceive.’ Not only could millions of citizens build their own sets at home, as did also many spies abroad, but in Berlin, London, Washington, Moscow, Tokyo electronic eavesdroppers were empowered to probe the deployments and sometimes the intentions of an enemy without benefit of telescopes, frigates or agents.
One of the themes in this book is that the signals intelligence war, certainly in its early stages, was less lopsided in the Allies’ favour than popular mythology suggests. The Germans used secret knowledge well to plan the 1940 invasion of France and the Low Countries. At least until mid-1942, and even in some degree thereafter, they read important Allied codes both on land and at sea, with significant consequences for both the Battle of the Atlantic and the North African campaign. They were able to exploit feeble Red Army wireless security during the first year of Operation ‘Barbarossa’. From late 1942 onwards, however, Hitler’s codebreakers lagged ever further behind their Allied counterparts. The Abwehr’s attempts at espionage abroad were pitiful.
The Japanese government and army high command planned their initial 1941–42 assaults on Pearl Harbor and the European empires of South-East Asia most efficiently, but thereafter treated intelligence with disdain, and waged war in a fog of ignorance about their enemies’ doings. The Italian intelligence service and its codebreakers had some notable successes in the early war years, but by 1942 Mussolini’s commanders were reduced to using Russian PoWs to do their eavesdropping on Soviet wireless traffic. Relatively little effort was expended by any nation on probing Italy’s secrets, because its military capability shrank so rapidly. ‘Our picture of the Italian air force was incomplete and our knowledge far from sound,’ admitted RAF intelligence officer Group-Captain Harry Humphreys about the Mediterranean theatre, before adding smugly, ‘So – fortunately – was the Italian air force.’
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.
