The British military establishment ended the First World War with a newly created independent air force that had yet to test fully its hopes and ideas for the application of air power at all levels of war. Lessons learned and ideas on how best to apply air power in any future conflict would have to be developed in the operational vacuum of the interwar period as there was no longer a hostile first-class European military power against which to conduct operations. Britain was also militarily, economically and socially unable to undertake such a conflict for the foreseeable future. 1 The development of air power, as well as the very existence of the RAF as an independent force, was at a critical juncture in 1918. The decisions taken in the first years after the First World War were instrumental in how the RAF utilised air power until the end of the Second World War.
The experience of the First World War allowed the newly formed RAF to develop its ideas in a more coherent fashion and the fundamental principles were codified by Trenchard. These were (1) maintenance of initiative through offensive operations; (2) the concentration of force; (3) the command and control (C2) of aircraft being centralised (which would increase the concentration of force), and (4) the gaining and retention of air superiority. 2 The most important of these principles, which was to both drive and guide the theoretical thinking about the application of air power, was the fundamental need to gain, at the very least, local air superiority. Through the gaining of air superiority, other air power missions could be conducted, such as close air support, battlefield air interdiction and strategic bombardment. Apart from the gaining of air superiority, these principles were fundamentally at odds with how the army thought air support should be provided, although there was disagreement as to what air superiority entailed. The army felt that the primary role of the RAF in air support was to attack front line positions as and when required. 3 The army had become accustomed to a force dedicated almost solely to the support of its troops despite the creation of IF. For almost the entirety of the First World War, Trenchard saw the best role for aircraft as support for the army, and so it is not unreasonable to think that the army believed that this would continue with him as CAS.
Much has been claimed about the development of the army co-operation role by the RAF during the interwar period. Some have gone so far as to claim that very little was done in this area, and that what was done was almost an insignificance. Simon Coningham has argued that âdespite the concept of air-ground co-operation being largely ignored by both the RAF and the Army in Great Britain, the RAF was flexible and tactically acute enough to resurrect it when necessary to its imperial operational objectivesâ. 4 Richard Muller has argued that âThe perception that close air support was a costly luxury and an aberration would dominate the next quarter-century and contributed materially to the RAFâs failure to advance its close-support practises during the inter-war period.â 5 This chapter will demonstrate, however, that this is not the case and that whilst it was not an overriding priority for the RAF before 1939, much good work was done. It will also highlight the developments that were made in army co-operation ideas across the British Empire and investigate the difficulties faced by all the services, with particular reference to the RAF, during the very difficult interwar periodâfinancial stringency, the disarmament movement supported by the general public and the political class of Britain, and the difficulties caused by the need to rearm and reinvigorate the British aircraft industry. This will provide the necessary historical context for an analysis of the army co-operation exercises, the developments that emerged from them and how they were applied during the Battle of France in 1940.
Many of the issues encountered during the army co-operation missions in the Second World War had already been experienced in the exercises of the interwar period and it was here that ideas were first put forward to resolve them. These exercises, as well as the results arising from their theoretical development, will be highlighted in greater detail in this chapter. The ideas that emerged from these exercises helped to form the theoretical basis developed by Army Co-operation Command and allowed it to transform the thinking on tactical air power in Britain. The development of army co-operation, in its many facets, was, on the face of it, the most logical path for the RAF to follow, based on their experiences in the First World War. This option, however, placed the very existence of the RAF as an independent force in grave danger as it would, and indeed did, lead to calls from the senior services to return to the pre-1918 establishment of an RNAS and RFC.
It was partly due to this potential disbandment that the RAF looked to develop ideas that involved the projection of air power at the strategic, rather than the tactical, level of war. Due to the inconclusive results of the strategic bombardment missions conducted by the RAF towards the end of the First World War, they could express their ideas about its impact with a greater freedom of imagination. 6 The RAF were able to stave off calls for their disbandment, and increase their funding relative to the Royal Navy and army by stressing the potential impact of air power at this level of war on the enemy home population. This, they argued, could only be achieved by an independent air force and was enhanced by the lack of an early warning system that would allow for the interception of hostile bomber aircraft. 7 The monies available to the governments of the interwar period, however, were not enough to allow the RAF to build up an air force that was both equipped to conduct large-scale operations immediately and able to create the necessary establishments to allow them to develop their in-house education and training. Trenchard was forced to make this decision very soon after the end of the First World War, and he chose to use the limited funds available to build up the intellectual and physical framework of the RAF through institutions such as the RAF College at Cranwell, which could be added to when required and the necessary funds became available. 8
Army co-operation was never a priority for the RAF at this time but it is incorrect to say that they simply forgot how to support the army. By November 1918, the RAF was relatively adept at army co-operation. One issue made apparent during the Hundred Days offensives, however, was how to provide the myriad of army co-operation missions during semi-mobile warfare. Aspects of army co-operation that had functioned well during the static trench warfare phase of the First World War, such as artillery spotting, began to see a drop off in efficiency as the C2 system for controlling aircraft found it difficult to keep pace with the advancing artillery batteries for which they were expected to spot. More direct support of land troops, such as through close air support, was inherently dangerous given its close proximity to both the ground and enemy forces. 9 This potential increase in danger was misinterpreted by the RAF in the early interwar period in order to provide the necessary reasoning not to concentrate on this aspect of air power, allowing a focus on its strategic application instead.
The figures used by the RAF to highlight the risk to both pilot and machine in conducting these missions was based on one single action in support of ground troops at the Battle of Amiens where casualties were particularly high. Alistair McCluskey has described the experience gained at Amiens as providing âa critical point of reference that directly influenced the development of British airâland battle in the interwar period and its subsequent conduct in the Second World Warâ. 10 With the RAFâs change of attitude towards this form of air power, however, the status of army co-operation and the pilots in the relevant squadrons dropped significantly. This caused a large turnover in personnel that hampered the training and development of these squadrons. An army co-operation squadron was no longer a base from which a promising junior officer could launch a career. Whilst there are isolated examples, of people who did work within army co-operation and rise to senior rank, such as Trafford Leigh-Mallory and John Slessor they are the exception rather than the rule. Charles Carrington, an army officer seconded to Bomber Command during the Second World War, noted in his memoirs that those involved in army co-operation work âdid not win favour or rewardâ in the interwar period. 11
The arguments over both the form of air support and the numbers required to provide it began almost as soon as the First World War had ended and thoughts had turned to the next possible conflict. These arguments and the development of army co-operation before 1939 must be seen against the difficult economic circumstances that prevailed in terms of monies available to the governments of the day to equip and expand the three services. 12 The instrument used to restrain military spending at this time was the Ten-Year Rule, which stated that the services should base their spending plans on the assumption that Britain would not be involved in any major war against a first-class power for ten years. 13 It is not the intention of this book to delve into the debate about the Ten-Year Rule as this sits outside of its scope. 14 However, the policy had a major impact on relations between the three services and was a major source of friction as the newly established RAF looked to cement its place in the British military establishment. 15
When the rule was first introduced in 1919 by Winston Churchill, it was a sound assessment of the European strategic situation. When it was continued on an annual rolling basis in the 1930s, the strategic situation had changed dramatically for Britain. 16 The reduction in monies available did not only impact on the services themselvesâthe RAF, which relied upon private industry for the supply of its airframes and engines, implemented procurement policies that kept as many manufacturers as possible in business. 17 One advantage that the Rule gave Britain was that it had not overly invested in a large air force composed of wooden biplanes that became obsolete with the development of all-metal monoplanes and was in a better position than it might have been when the decision was taken to rearm in the mid-1930s. 18
The arguments between the services, partly as a result of the Ten-Year Rule, led the government to investigate the roles that were undertaken by each of them, and through the interim report of the Committee on National Expenditure under Sir Eric Geddes, came to the conclusion that there was âserious...