SURVEYING THE WRECKAGE: 1945
In August 1944 Spaatz had asked his air force commanders to speed up the defeat and surrender of Germany so that a special committee could review what bombing had achieved in Europe in order to apply their conclusions to the war against Japan.367 The idea of undertaking a serious scientific survey of the bombing campaign had first been aired in the spring of 1944 and was enthusiastically supported by Spaatz, who approached Arnold and Lovett on the subject in April. Arnold wanted an independent assessment of the question, ‘Was strategic bombing as good as we thought it was?’, and with Lovett’s strong support the air force put together a plan which they presented to the president in September. Roosevelt approved the project and asked the Secretary of War, Henry Stimson, to establish the new office. Arnold chose a businessman, Franklin D’Olier, President of the Prudential Life Assurance Company, to head a board of professional economists, academics and analysts, and on 3 November Stimson formally set up the United States Strategic Bombing Survey (USSBS), based in London; a forward base was set up after the end of the war in the resort town of Bad Nauheim, with branches in other German cities. Approval was given to enlist 300 civilians and 850 officers and men from the armed forces.368 Their task was to produce comprehensive reports not only on the results of American bombing but also on the RAF offensive. The survey began its operations before the end of the war, as territory was gradually liberated from German occupation.
The RAF also began to plan for a possible survey in the spring of 1944. The British side assumed that they would collaborate with the Americans, and on 10 August 1944 the chiefs of staff authorized the Air Ministry to prepare an inter-Allied survey organization. Arnold was solidly opposed to any joint venture, though it did not stop the USSBS commenting at length on British bombing. By the time Sinclair finally proposed a survey to Churchill in December 1944, it was to be a British project. Churchill brusquely dismissed the idea of what was now called the British Bombing Research Mission, partly because of the assumption that it would take at least 18 months to report – and hence be of no use in the war against Japan – but also because he deprecated tying up ‘the use of manpower and brainpower on this scale’.369 Instead of the large staff envisaged by the Ministry, Churchill recommended a limited group of 20–30 people. His intervention invited months of bureaucratic wrangling over who should take part and at what cost, until Portal finally lost patience, abandoned the idea of the Mission, and recruited a small unit already established at SHAEF, the Bombing Analysis Unit, as the core of a British Bombing Survey Unit (BBSU). The new organization was formally launched on 13 June 1945, months after the American survey had begun its work.370 The Unit was to be run by an air force officer, Air Commodore Claude Pelly, and the SHAEF target adviser, Solly Zuckerman, assisted by staff from the RE8 division of the Ministry of Home Security, which was to be closed down when the war ended.371 Both men were committed enthusiasts of the attack on communications, and their work and the subsequent reports reflected their bias. Their terms of reference were to examine the effects of bombing on German fighting capacity, the effectiveness of German defences and the accuracy of assessments of damage.372 Already hostage to the small size and limited resources of the new Unit, the BBSU became a vehicle for Zuckerman to argue his transport case at in contrast to the disinterested analysis sought by the American Air Force. Much of the work of the BBSU was reliant on American research and expertise, a reflection of the rapid shift in the balance of power between the two air forces.
The process of collecting files and statistics and interrogating senior German personnel began at once. By the end of May a great many of the key figures had already been interrogated, including Göring, whose transcripts reveal an almost boyish desire to share his knowledge of the German Air Force with the victors. The provisional conclusions among the cohort of German airmen, engineers and ministerial staff subject to interrogation were almost unanimous. A British intelligence assessment, ‘Factors in Germany’s Defeat’, produced by 17 May, included an interrogation with Adolf Galland, who ranked the offensive against transport, then oil, then the air force as the most decisive.373 In mid-June a full report of interrogation extracts was produced by the director of American Air Force Intelligence at SHAEF, George MacDonald. They also showed that the three critical targets were considered to be oil facilities (‘The general opinion of the German leaders is that the attack on synthetic oil was the decisive factor’), communications (‘brought about the final disruption of the German war effort’), and the German Air Force – achieved through attacks on aircraft production, airfields and combat attrition.374 Göring thought the collapse of oil supply to be the single most critical factor – ‘without fuel, nobody can conduct a war’ – while Albert Speer, Hitler’s Minister for Armaments and War Production, ranked communications at the top of the list of critical targets. Erhard Milch, Göring’s deputy at the Air Ministry, ranked ‘synthetic oil plants and railway communications’ together.375 On area bombing the German judgement was largely negative. It did not ‘cause the collapse of the German people’ and was regarded, according to MacDonald, as ‘the least important of the major target complexes’. When Göring was asked in one of his first interrogations on 10 May whether precision or area bombing was more effective in Germany’s defeat, he replied: ‘The precision bombing, because it was decisive. Destroyed cities could be evacuated but destroyed industry was difficult to replace.’376 In a USSBS interview on 24 May with Karl Koller, the last German Air Force chief of staff, Koller claimed, not altogether plausibly, that without precision attacks ‘Germany would have won the war’. He confirmed that oil and transport facilities were fatal targets for Germany.377
In general, Allied assessments reached the same conclusion. The USSBS produced over 200 detailed reports on every aspect of the bombing war, but the Over-all Report reflected the views of those interrogated. The Survey board had an interest in arguing that in the Western theatre air power was decisive, thanks chiefly to the air victory achieved over Germany in the spring and summer of 1944, ‘which made devastating attack on [the German] economy possible’. The report highlighted the relative failure of area attacks, which ‘had little effect on production’, while singling out oil and communications as critical. The attack on Ruhr steel in late 1944 was also added as a key factor, but the choice of this period rather than Harris’s ‘Battle of the Ruhr’ in 1943 added weight to the implication that it was American bombing that had been decisive. The treatment of city attacks (four pages out of 109) minimized their impact on economic output. Statistics were presented which showed that city attacks, overwhelmingly by the RAF, cost only around 2.7 per cent of German economic potential in the target areas. It was calculated that the combined offensive cost 2.5 per cent of potential German output in 1942, 9 per cent in 1943 and 17 per cent in 1944 (figures that were roughly consistent with the claim that 5 per cent of British output was lost during the lighter Blitz). Since area bombing in 1944 experienced diminishing returns, ton for ton, by dropping on previously destroyed areas, the implication again was that most of the production loss was due to American bombing of selected target systems.378
Perhaps more surprisingly, this was the conclusion also arrived at by the BBSU when its main report was finally completed in draft in June 1946, almost a year after the USSBS. There were months of delay in arguments with the senior commanders who had been responsible for the offensive, except Harris, whose views were not canvassed. Unlike the USSBS reports, which were easily available, the BBSU final survey and subsidiary reports were given only a limited circulation. The final report was critical of almost all phases of Bomber Command’s activities except the final phase against oil and communications targets. A good deal of the report was devoted to demonstrating that the final industrial and military crisis in Germany was a result of the disintegration of rail and water traffic: ‘Enough has been said to show that the collapse of the German transport system … was the fundamental and main reason for the contemp
oraneous collapse of German war industry.’379 This fitted with Zuckerman’s own prejudices. Even the assessment of oil supply, which the report regarded as critically disabling, concluded that the offensive against transport was responsible for preventing the recovery of Germany’s oil position.380 The judgement of the report on area bombing of German cities was even more damning than the USSBS. Using methods pioneered earlier by the RE8 department, Zuckerman’s team calculated on the basis of 21 heavily bombed industrial cities that area bombing reduced potential war production by 0.5 per cent in 1942, 3.2 per cent in the first six months of 1943, 6.9 per cent in the second six months of 1943, and then approximately 1 per cent throughout 1944, when bombing again brought diminishing returns and area bombing was only one of the factors affecting output. The figures were lower than the USSBS estimates (which had been speculative extrapolations) because they were based on careful research across a range of cities and because they measured potential loss against a rising trend of output. In all 21 cities studied, war production expanded faster than it had done in a control cohort of 14 cities not subject to attack.381
Damning though this indictment was, and partial though Zuckerman’s position appeared to be, it fitted not only with the interrogation evidence but with the views among Air Ministry officials and RAF commanders in the two years after the war when hard thinking had to be done about what had been achieved by Bomber Command, rather than the Combined Offensive as a whole. Sydney Bufton, once an advocate of incendiary attacks on cities, produced a long critical assessment of area bombing in January 1945, in which he admitted the failure at Hamburg in 1943 as an example of misplaced confidence in the economic or morale effects of heavy urban destruction.382 Norman Bottomley, Portal’s deputy for the last three years of the war, and Harris’s successor as commander-in-chief at Bomber Command, contributed an assessment of British bombing at a workshop organized by Tedder, now chief of staff, in August 1947 under the codename ‘Exercise Thunderbolt’. The effect of area attack, he concluded, was ‘great but never critical’, nor was enemy morale ever ‘critically undermined’, a fact he blamed on poor intelligence. ‘Offensive against oil and transportation proved most effective,’ he wrote, but only after the achievement of the vital precondition of air superiority.383 A lecture given in 1946 by one of the RAF officers on the British survey highlighted air force attrition, oil and transport again, but argued that ‘little worthwhile’ was achieved by area attacks before 1943, and thereafter the resistance of the German population and the reserve capacity of German industry made them ‘resilient to area attack’.384 Given the uniformity of opinion on both the German and Allied side, the one based on experience, the other on extensive research, it is surprising that the effects of bombing have occasioned so much debate ever since. The proximate causes – defeating the German Air Force and emasculating oil supply and transport – are unlikely to be undermined by further research.
The statistics nevertheless require some explanation about why the overall impact of bombing for much of the war period should have been so much lower than expectations. At its simplest level, as Henry Tizard put it after the war, ‘You can’t destroy an economy.’385 American economists drafted in to advise the United States war effort in Europe were critical of the idea that bombing either areas or specific industries would of itself produce cumulative damage. The Hungarian émigré economist, Nicholas Kaldor, a member of the USSBS team, argued that the critical factors in choosing economic targets were the degree of ‘cushion’, the degree of ‘depth’ and the degree of ‘vulnerability’. The first was governed by the existing elasticity of the economy in terms of finding additional or substitute resources for those lost to bombing; the second measured the extent to which a particular product or resource was close to actual military use, since the further back in the production chain, the longer the time before bombing would affect military performance; the third was governed by the extent to which concentrated, and relatively inflexible, capital industries could be effectively destroyed from the air.386 Kaldor and his economist colleagues argued that for most of the war period Germany had a large cushion of resources of capital stock, labour and raw materials that could be allocated to sustaining war production. His conclusion was based partly on the assumption, now generally regarded by historians as invalid, that Hitler did not order full-scale mobilization until 1944. The degree of allocation of productive resources to war purposes was in fact high from the start of the war, but many of the economies of scale characteristic of large-scale industrial production became effective only by 1942–3, while the unanticipated length of the campaign against the Soviet Union distorted war production plans at a critical juncture in 1941–2.387
Yet Kaldor was not wrong to argue that a cushion existed. The index of armaments output showed that German production increased threefold between 1941 and 1944, despite all the bombing; some individual categories of weapon expanded more than this, fighter aircraft by a factor of 13, tanks by a factor of five, heavy guns by a factor of four.388 As a result of the conquest of much of Continental Europe, Germany had access to large resources beyond her borders. Although this also involved economic costs to Germany, occupation meant that over 119 billion marks were contributed to Germany’s war budget, one-quarter of all the costs of the armed forces; 7.9 million forced workers and prisoners of war were compelled to work in Germany, while an estimated 20 million more worked on orders for the German war effort in the occupied zones.389 Moreover, German technical and organizational ingenuity made it possible to find substitute products or productive capacity even for ‘bottleneck’ industries like ball-bearings, where, as Kaldor argued, the target had ‘run away’ by the time the Allies attacked it again in 1944.390 The German economy, wrote the USSBS economist J. K. Galbraith in an early evaluation, was ‘expanding and resilient, not static and brittle’.391
For most of the Allied bombing offensive these factors were either insufficiently known or not understood and bombing, as a result, was relatively ineffective. Only in 1944, with the American decision to focus on enemy air power, oil and transport were three targets chosen which fortuitously matched Kaldor’s calculation. The attack on the German aircraft assembly industry, as part of the assault against enemy air power, was the least successful because of the substantial cushion that existed in dispersing the final stages of production; all German leaders claimed, however, that repeated attacks on aero-engine production would have been critical. Oil and transport facilities, on the other hand, had poor cushioning possibilities once heavy attacks began, were highly vulnerable to sustained attack, and had a positive ‘depth’ factor because both were needed almost immediately by the armed forces and by industry to sustain fighting capability and output. The campaign against the German Air Force was indeed a precondition for the success of the campaigns against oil and transport, and was a direct result of the changing tactics of day-bombing and the high priority given by Spaatz to suppressing German air power as fully as possible. When German oil installations and air force operations both threatened a limited revival in late 1944, Spaatz shifted once again to priority oil and counter-force attacks. It is difficult not to argue that the United States air forces had a surer strategic grasp and a clearer set of strategic objectives than did Bomber Command. Counter-force operations and the search for target systems that would unhinge the enemy’s military efforts were central elements in American wartime air doctrine. The RAF, by contrast, thought of air power more as a form of blockade, and was never enthusiastic about counter-force operations or attacks on transport, though both had been adopted in the Mediterranean campaign. The defeat of the German Air Force over Germany and the massive dislocation of German transport were primarily American achievements.
Area bombing was nevertheless, despite its critics, not entirely without impact on the German war effort. The random and scattered nature of much of the city-bombing campaign had evident opportunity costs for the German war effort, in addition to the effects of substantial civilian c
asualties and damage to housing. Consumer goods production had to be increased in 1943, against the trend of total war mobilization, to meet the needs of bombed-out families. The night-bombing interrupted utility services, hit shops and occasionally factories, necessitating the allocation of additional resources of manpower to cope. There is no way in which these kind of costs can be computed, any more than there was in Britain as a result of the Blitz. The real question concerns assessment of the damage done to the German industrial working class, since this was the whole rationale behind the campaign. It has never proved possible to calculate the number of workers killed, rather than non-workers (elderly, women with families, children, etc.), but some sense of the limitations of any such assessment can be found in the death statistics in Hamburg, where on the night of the firestorm in 1943 which killed over 18,000 people, only 280 were killed in the factory district, away from the main area of bombing.392 Workers were not always the most likely victims, but even if the estimated total of 350,000 German dead from bombing were all workers, that would still have represented only 1.6 per cent of the German industrial and rural workforce, some of whom would have been killed by American daytime bombs rather than by the RAF.
The other argument for area bombing was the high level of absenteeism it would induce, though the British evidence, on which the strategy was based, was scarcely convincing. German records show that absenteeism as a direct result of bombing made up 4.5 per cent of hours lost at the height of the bombing in 1944; an additional 10.8 per cent of hours were lost due to illness or leave, though these may well have been a response to circumstances caused by bombing. Figures of hours lost due to bombing were higher in targeted industries (7.9 per cent in shipbuilding, 10.6 per cent in vehicle production), but much of this loss was the result of precise attacks by day rather than by Bomber Command at night.393 The state of ‘morale’ among the German population, which was also a stated objective, will be examined in greater detail in Chapter 7.
The Bombing War: Europe 1939–1945 Page 55