The concept of the independent strategic air offensive as the decisive means to undermine the enemy war effort took root between the wars only in Britain and the United States. Even here the idea was hedged about with restrictions, not only as a result of the dubious legality of a campaign waged against the civilian home front, but because of pressure from the two senior services, army and navy, to make air power conform to the general aim of the armed forces to defeat the enemy army and navy in the field. In the United States the air forces remained a part of the army, subject to army doctrine. In the ‘Fundamental Principles for the Employment of the Air Service’, published by the War Department in 1926, air force organization and training was based ‘on the fundamental doctrine that their mission is to aid the ground forces to gain decisive success’.89 A board established in 1934 to reassess the role of what was now called the Army Air Corps was told by the army deputy chief of staff, Maj. General Hugh Drum, that in the army’s opinion no operations should be undertaken by air forces which did not contribute directly to the success of the ground forces. ‘Battle is the decisive element in warfare,’ Drum continued, whereas independent air operations ‘would be largely wasted’.90 In 1935 the army agreed to the establishment of a GHQ Air Force, an independent component of the Air Corps, but its object, like the Soviet AON, was to bring additional reserve air power to bear at decisive points in repelling an unlikely enemy invasion, not to conduct strategic operations distant from the battlefield.91 In the absence of any real danger and faced by an unhelpful Treasury, the Air Corps mustered an exiguous force. In 1932 there were just 92 light-bomber aircraft on hand.92
Under these circumstances American airmen found themselves compelled to elaborate an unofficial theory of strategic bombing in tandem with the formal commitment to support the operations of the army. The American airmen who had witnessed the bombing of London in 1917–18 were more impressed by its results than their German counterparts. In the early 1920s the chief of the Air Service, Maj. General Mason Patrick, publicly supported the idea that ‘decisive blows from the air on rear areas’ might end future conflicts, even while he endorsed his service’s formal commitment to direct army support.93 His deputy, Brig. General William (‘Billy’) Mitchell, was an even more outspoken advocate of air power as a new way of war. His enthusiasm for an autonomous air arm was based on his conviction that attacks on ‘transportation and industrial centres’ with high explosive, incendiary and gas bombs could prove to be a decisive contribution to victory. Mitchell elaborated the concept of the ‘vital centres’ in the enemy’s civilian war effort, whose destruction from the air might render surface operations by the army and navy redundant.94 Although these views were not turned into doctrine – Mitchell was court-martialled in 1925 for his outspoken demands for an independent air force – they survived in air force circles as an unspoken commitment to the idea that in a future war between modern, highly urbanized and industrialized states, air power could uniquely destroy the key targets that kept that sophisticated network in being.
The idea of the vital centres lay at the root of the future elaboration of American bombing strategy in the Second World War. The commander appointed to the GHQ Air Force in 1935, Maj. General Frank Andrews, privately supported the idea that independent air operations against factories, refineries, power plants, utilities and centres of population were the most effective way to use bomber aircraft. The concept was elaborated and taught at the Air Corps Tactical School in the 1930s by a number of officers who were to become prominent organizers of the American bombing effort in the 1940s. Unlike European air forces, American airmen argued that attacking the more vulnerable home front made greater strategic sense. ‘Civilization has rendered the economic and social life of a nation increasingly vulnerable to attack,’ ran one lecture in 1935. ‘Sound strategy requires that the main blow be struck where the enemy is weakest.’ The will of the enemy population, it was argued, could be broken only by assaulting the ‘social body’, a metaphor for the elaborate web of services, supplies and amenities that held modern urban life together. In a list of factors that represented the capacity of a nation to sustain a war effort, the military system was placed fourth, behind the ‘social, economic and political systems’ that nourished the military effort in the first place.95 Major Harold George, who later drafted the plan for the American air offensive against Germany, argued not only that modern industry had created an ‘economic web’ which could be interrupted by bombing, but that the moral effect on an enemy population ‘by the breaking of this closely-knit web’ might end the war on its own.96 To confirm these speculations, the Air Corps Tactical School commandant, Major Muir Fairchild, conducted an elaborate exercise in April 1939 on the vulnerability of New York and its surrounding area as a model for all cities, ‘the most important and the most vulnerable’ element of the modern state. The conclusion was that two squadrons of bombers, attacking with 100 per cent precision, could knock out the entire electricity-generating system in New York and paralyze the whole city at a stroke.97
The Air Corps operated in a vacuum in the 1930s in the absence of permissive air doctrine and the necessary aircraft equipment to justify the idea of a strategic offensive. In 1933 the Air Corps was allowed to explore the development of a four-engine bomber in order to ensure that military air technology kept abreast of the more rapid developments in civil aviation. The development contract was won by the Boeing Airplane Company, which by 1935 had produced a prototype designated the XB-17, forerunner of the B-17 ‘Flying Fortress’, with a range of 1,800 miles, carrying 4,000 lbs of bombs.98 The army had approved the project only as a defensive aircraft for the long routes to Panama, Alaska and Hawaii, but in 1936 army thinking changed and the production order was cancelled. The army, impressed by the results of front-line support operations in Spain, thought medium bombers promised ‘greater efficiency, lessened complexity and decreased cost’.99 The development of the B-17 was squeezed to the slenderest of margins. It was saved only by a sudden revolution in political support for the Air Corps. In late 1938 President Roosevelt authorized a large-scale expansion of American military spending, including a major commitment to the expansion of the air force (partly to ensure that France and Britain could be supplied with aircraft for the growing crisis in Europe). An Air Board appointed in March 1939 strongly supported the idea of a heavy bomber and the B-17, from a single development model, became overnight the heart of American air strategy. Plans were developed to build 498 by 1941 and 1,520 by the end of 1942, the first commitment of any air force to the employment of a heavy four-engine bomber.100
One of the companies asked to produce the B-17, the Consolidated Airplane Company, instead designed its own bomber model in 1939 capable of carrying up to 8,000 lbs of bombs, with a higher speed and a maximum range of over 2,000 miles. This was accepted by the Air Corps after trials and modifications in 1940 and became the B-24 bomber, nicknamed ‘Liberator’ by the RAF, when a number were sent to Britain in 1941. It eventually became the standard American bomber, with 18,400 produced by 1945. The new bomber designs, together with the revolutionary M-4 Norden stabilized bombsight, first developed by the Dutch-American engineer Carl Norden for the United States Navy in the late 1920s, meant that the United States was better placed to operate a strategic air campaign in the early 1940s than any of its potential enemies. In 1939 permission was given to begin development of a ‘superbomber’ with a range sufficient to reach Europe. What the Air Corps still lacked was any plan or doctrine which would allow it to use its enhanced power for what most airmen assumed was the primary function of the air force: to assault the ‘social body’ of the enemy.
In Britain, commitment to some form of an independent bombing offensive was kept alive throughout the twenty years that separated the unfought air campaign against Germany in 1919 and the onset of a second war in 1939. In this case, too, the RAF did not enjoy unlimited opportunity to develop either the doctrine to support an air offensive or the technology necessary to sus
tain it. In the 1920s there was relatively little thinking about the nature of an air offensive beyond speculation on Trenchard’s assertion about the probable vulnerability of civilian morale in any future conflict. When in the late 1920s the Air Ministry explored the possibility of a ‘Locarno’ war against France to help the Germans repel a possible French invasion in violation of the 1925 Locarno Pact, it was argued that even if the French bombed London, ‘we can count on our superior morale and striking power to ensure that the Frenchman squeals first’.101 In 1928 the British chiefs of staff insisted on securing a firm description from the RAF on ‘The War Object of an Air Force’. In the meetings that followed, the navy and army chiefs of staff made it clear that in their view the vague commitment to attacking the enemy economy and population was not only contrary to international law but departed from the traditional principle of war that the main effort had to be devoted to defeating the enemy in the field. An uneasy truce was established between the services on the basis that the aim of the air force ‘in concert with the Navy and Army’ was to break enemy resistance, and to do so ‘by attacks on objectives calculated to achieve this end’. This left Trenchard and the RAF with substantial leeway in defining just what those objectives were and how they might be attacked.102
Although the other services wanted the RAF to develop a balanced force, capable of offering them support and defending the country against air attack, the air force itself remained dominated by the idea that bombing defined its purpose as a modern force capable of revolutionizing warfare. In a survey of RAF development written after the end of the Second World War, Robert Saundby, deputy commander of Bomber Command during the war, claimed that the air staff in the 1920s ‘saw clearly that the bomb was the offensive weapon of the Air Force’; and indeed in the first edition of the RAF War Manual, published in 1935, it was claimed that ‘The bomb is the chief weapon of an air force and the principal means by which it may attain its aim in war’.103 When it came to thinking about what the bomb or bombs might be used for, RAF leaders continued to rely on unverifiable assumptions about the social fragility of the enemy. In the 1928 discussion organized by the chiefs of staff, Trenchard, like American airmen, had suggested that air power would have to be exerted against the ‘enemy’s vital centres’, where the enemy ‘is at his weakest’, but he made little effort to define what those might be.104 For much of the decade that followed, those British airmen who followed the ‘Trenchard doctrine’ fell back on bland metaphors about the social body, using, like American airmen, an anatomical language that created a deliberate abstraction in place of the real bodies that bombing would damage.105 The RAF War Manual claimed that all modern states ‘have their nerve centres, main arteries, heart and brain’. By attacking them, air forces would delay, interrupt and disorganize the vital centres to such a degree that the enemy’s ‘national effort’ would collapse, not only through injury to the social body, but by the effect this might have on the collective mind, as the Manual explained:
Moral effect – Although the bombardment of suitable objectives should result in considerable material damage and loss, the most important and far-reaching effect of air bombardment is its moral effect … The moral effect of bombing is always severe and usually cumulative, proportionately greater effect being obtained by continuous bombing especially of the enemy’s vital centres.106
The conviction that bombing must cause the physical and mental collapse of an enemy state dominated British air theory, as it dominated public anxieties about total war.
One reason why the RAF stuck with the idea that a powerful striking force of bombers would be the most effective way to exploit the potential of air power can be found in the nature of the combat experience enjoyed by British airmen in the interwar years. Instead of drawing lessons from the Spanish Civil War about the advantages of close-support aviation and air superiority, which was the conclusion drawn by other air forces, RAF doctrine was mainly informed by the experience of what was called ‘air policing’ in the Empire and Afghanistan.107 The use of aircraft to enforce local control against rebel tribes and tribesmen (described in the Manual as war against ‘semi-civilised peoples’) was taken as a paradigm to explain what might happen if a civilized state were subjected to a heavier level of bombing. Even tribal communities, it was argued, had vital centres which governed their existence; target intelligence on those centres would allow the small light bombers allocated to the operation to destroy them, and in doing so, to compel compliance from unruly subjects. John Slessor, Director of Plans in the Air Ministry in the late 1930s, gave a brutally frank description in his memoirs of why air policing worked: ‘Whether the offender concerned was an Indian Frontier tribesman, a nomad Arab of the northern deserts, a Morelli slaver on the border of Kenya, or a web-footed savage of the swamps of the southern Sudan, there are almost always some essentials without which he cannot obtain his livelihood.’108 A model example for the RAF was the bombing undertaken in Ovamboland in southern Africa in 1938, in which rebel chieftain Ipumbu of the Ukuambi tribe was brought to heel by three aircraft that destroyed his kraal (camp) and drove off his cattle. In this case, and others, emphasis was put on the ‘moral effect’ of coercive bombing, as well as its material impact.109 The practice of air policing using bomber aircraft as a ‘strategic’ tool was shared by all those who later held high RAF office in the Second World War: Charles Portal, wartime chief of the air staff; Arthur Harris, commander-in-chief of Bomber Command; Richard Peirse, his predecessor as commander-in-chief; Norman Bottomley, Portal’s wartime deputy. Later, in September 1941, Portal used the analogy to explain to Churchill the nature of the assault on the ‘general activity of the community’ in Germany: ‘In short, it is an adaptation, though on a greatly magnified scale, of the policy of air control which has proved so outstandingly successful in recent years in the small wars in which the Air Force has been continuously engaged.’110
This perception of bombing serves to explain the wide gap between the strategic vision at the heart of the interwar RAF and the reality of Britain’s bombing capability and defence strategy in the 1930s. Imperial air policing was undertaken in conditions of clear visibility, little or no opposition, and low-level attack, none of which would be true of an aerial offensive undertaken in Europe. As a result, colonial practice did not persuade Britain’s military leaders to bank everything on the bomber. Indeed, fear of bombing, particularly once Hitler’s Germany had been identified in the mid-1930s as the most likely potential enemy, acted as a powerful spur to change British priorities in the air to one that was more appropriately defensive. When the military Joint Planning Committee was asked in 1934 to estimate the probable effects of a German ‘knockout blow’ from the air, it was assumed that a week of bombing would produce 150,000 casualties and render millions homeless. Later estimates by the chiefs of staff continued to assume that these statistics were realistic – more than a match for the alarmist literature of the age.111 In 1937 the newly appointed Minister for the Co-ordination of Defence, Sir Thomas Inskip, told the RAF that the role of the air force was not to inflict a knockout blow on the enemy (which it was incapable of doing) ‘but to prevent the Germans from knocking us out’.112 The Committee of Imperial Defence spelt out guidelines for air strategy in which the air force would have to support the navy and army, defend the mainland United Kingdom from air attack, and try to inflict aerial damage on the enemy’s strike force. Instructions were given to prepare for a possible attack on German industry in the Ruhr, but only if political permission were given and only after the RAF had met its other commitments. Instead of a force dominated by a large component of bombers to assault the enemy’s war effort, the British defence chiefs insisted on a balanced force, a view with which a number of senior airmen agreed, despite the prevailing culture that bombing is what the RAF should do. Between 1937 and the outbreak of war this meant devoting the lion’s share of resources to Fighter Command, the air defence network and civil defence. As a result, RAF strategy seemed increas
ingly schizophrenic, one half emphasizing the strategic value of bombing, the other preparing to defend successfully against it.
For all the emphasis in air force circles on the value of a strike force, the technical preparations for an offensive were almost non-existent. Instead of the massed bomber fleets assumed to be necessary to inflict serious damage, the force was composed of a modest number of light and medium bombers, most of them incapable of reaching beyond the fringes of western Germany. More problematic was the absence of serious thinking about problems of navigation, bombing training, bombsights and bombing accuracy, reflecting an air force culture that played down the importance of technique and tactics.113 The RAF made generalists of the senior staff, who moved regularly between command in the field and office duty in the Air Ministry, discouraging the development of a corps of technically qualified airmen to match the Technical Office of the German Air Force. The British scientist, Sir Henry Tizard, chaired a committee set up in 1938 to give scientific advice to the RAF on bombing, but found senior commanders unenthusiastic about collaborating with science.
When an Air Ministry Bombing Policy committee was finally set up in March 1938 to explore the problems of how to reach, find and hit a target, it was acknowledged that a great deal more needed to be done to be able to do any of them. The bombsight was little different from those used in the First World War and navigation was undertaken either visually by day or by the stars at night. At the committee’s first meeting, the pessimistic conclusion was reached that new technical equipment was unlikely to produce any marked improvement in navigation or accuracy. Opportunities for accurate night-time bombing were expected to be ‘rare’.114 Bombing trials showed that with high-level bombing by day, the form most favoured, only 3 per cent of bombs were likely to hit their target, and in a shallow dive, 9 per cent.115 By March 1939 the Air Ministry planning department bemoaned the failure to mobilize all the country’s scientific resources to produce a better bombsight, and suggested that political pressure should be exerted on the United States to provide the Norden gyroscopic model, but it was largely a problem of their own making.116 A month before the Munich crisis in late September 1938, the commander-in-chief of Bomber Command, Air Chief Marshal Edgar Ludlow-Hewitt, told the Air Ministry that under present circumstances it would be best to rely on the North Sea and air defences in the event of war with Germany. The attempt to bomb Germany ‘might end in major disaster’.117
The Bombing War: Europe 1939–1945 Page 8
