‘Total war’, modern industrial war, involving the mobilization of society and the erosion of the distinction between military and civilian, continues to attract the interest of scholars. Yet as Roger Chickering and Stig Förster observed in the final instalment of an epic five-volume study of the phenomenon, there still is no ‘general consent’ as to how to define it.Footnote 1 This impressive and important series examined the period from the civil war in the United States to the arrival of the nuclear age at the end of the Second World War. Like other studies it embraced an overarching framework of progressive, seemingly inexorable, escalation, as war became a black hole that threatened to swallow the universe around it. Fortunately this meta-narrative was not completely correct, as the course of the twentieth century shows.
This article attempts to advance the debate over the ‘total war’ phenomenon by analysing its polar opposite: restraint. All belligerents operate under constraints. However, the importance of restraint has been submerged under the rising tide of the ‘total war’ literature. The rare studies of the phenomenon have mostly examined it in terms of a quid pro quo between belligerants or criticized its absence.Footnote 2 Yet as the expanding directions in which war can be taken continues to outstrip countries' wherewithal, the importance of the limits and choices surrounding the mustering of a nation's resources for war grows. This makes restraint as important as expansion in understanding the direction and speed of a nation's mobilization. Comparing the choices countries make undercuts the view that ‘total war’ is simply a sloping path that all states follow; a course whose inexorable descent will inevitably force the distinction between civilian and military to give way.
Investigating restraint questions both the idea of inevitable chronological escalation as well as its corollary, a nebulous ‘totality’ in which everything is subsumed by war. To examine one specific example of restraint and the reasons for it will address both of these problems. To focus on the actual combination of forces that gave rise to restraint provides a specificity of cause and effect that the concept of ‘total war’ often lacks, while the exercise of restraint shows that escalation was not inevitable.
The first part of this article outlines how, during the First World War, France decided to practise a considerable degree of restraint in pursuing a new dimension of warfare that the conflict had opened up: strategic bombing. This restraint was exercised despite considerable foreign and domestic pressure to take the war to German civilians. In using air power the French emphasized the military front and targets closely related to it such as munitions factories and railways. This approach was reflected in the nature of the privileged place aviation held in the mobilization of the country's limited resources. France's strategic bombing policy was half-hearted, thus maintaining as much of a distinction as possible between the battlefield and the city. Yet the extent of France's wartime mobilization meant that at the end of 1918 it was an aviation superpower, but not one based on strategic bombing.
The second part of this article uses the rejection of the French approach to bombing by its key ally, Great Britain, as a comparison to understand better the importance of the factors behind France's restraint. The British emphasized long-range bombing including military targets inside cities and, ultimately, civilian ‘morale’. Britain ended the war with a new armed service, the Royal Air Force (RAF), whose relatively well-financed mission was primarily strategic bombing and air defence. The combination of French restraint, and Britain's lack of it, highlights the very different directions in which ‘total war’ could take states, as they were forced to choose how far and along which lines they were going to carry mobilization.Footnote 3 The article concludes with some reflections on the implications that an examination of restraint has for studying modern wartime mobilization.
I
The First World War was a crucial period in the development of aviation. Rapid and intense mobilization brought a dramatic evolution in the power and possibilities of an air force. France led this process. Over the course of the war, the country's long and glorious aeronautical tradition, and its infrastructure, were successfully mobilized. By the end of the conflict France was the world power in aviation, with the largest air force of any nation. Despite many weaknesses and political divisions, the French possessed ‘the most successful aviation production apparatus in the world’. This success and efficiency stemmed in part from the government's procurement policy favouring the standardization of aircraft types and industry's capacity to produce large quantities of high-quality aircraft engines. The result for the French military in 1918 was one new aircraft every fifteen minutes.Footnote 4
As with trench warfare, mobilization brought escalation and the intensification of combat. The growing number and quality of aircraft led to a spiralling battle for air superiority, one whose importance increased with the rising value of reconnaissance planes and bombers for short-range operations. The significance of aviation in determining events on the battlefield was driven home for the French in 1916 at Verdun and the Somme. Their growing fighter force was concentrated in ever larger formations in an effort to gain control of the airspace over the battle and allow reconnaissance, artillery spotting, and tactical bombing. In this process of expansion the military performance of long-range bombing lagged behind that of other types of aircraft that were primarily deployed near the front. For example, French attacks against German cities in 1915 suffered high losses and limited results given the constrained bomb load, difficulty of navigating long distances, and the limited accuracy of the raids. Improvements in defensive measures including anti-aircraft artillery would render long-range raids all the more expensive. In October 1916 the French were losing so many bombers that they were forced to suspend daytime operations, shifting to night bombing raids. This experience was remarkably similar to that of the other major combatants. Despite improved equipment and tactics, Britain, France, and Germany all suffered from extremely high losses of long-range bombers for often limited results. As the war approached its close, in the summer of 1918, the French monthly wastage rate on the western front for these aircraft would at times surpass 50 per cent.Footnote 5
The evolution of aviation over the battlefield was closely linked to the production of aircraft on the ‘home front’. The importance of fighters and reconnaissance aircraft brought large and profitable orders for manufacturers. Bombers were more costly and complicated to build, a price that was further increased by their high wastage rate. The aircraft's size and sophistication required an even greater share of scarce resources such as skilled manpower and raw materials that further complicated production and completion rates. Bombers also required a well-trained crew and extensive logistical support. These rising demands weighed on both Germany and the allies. In the case of the former, efforts beginning in late 1916 to intensify aircraft production were successful but growing shortages of labour and material meant that in the last months of the war planes such as the R6, the ‘only giant bomber to enter serial production’, were still few in number. Unsuccessful and costly raids against Britain pushed Germany in May 1918 to discontinue the attacks. The change in policy stemmed from the ‘the lack of results for their effort, especially in light of the drain from other production’.Footnote 6
When compared to Germany, Britain and France were able to invest more resources in aircraft construction, the immense wartime demands on manpower, industrial capacity, and material also meant intense competition for scarce resources. Some specialization occurred, for example France became a key producer of airplane engines for the allies. However this did little to alleviate shortages and conflicting allied priorities. The hopes of many in Britain and France that the 1917 entry of the United States into the war would provide the immense number of aircraft necessary to make large-scale strategic bombing a decisive weapon were dashed thanks to the inevitable delays and difficulties in bringing together policy, men, money, material, and technology. In the face of increasingly tough choices, both the British and French, like the Germans, accorded an important priority to aircraft production and the attendant need for pilots and support. At the end of the war, Britain had the largest aircraft industry in the world with some 268,000 employees, while France employed 185,000 (and Germany roughly 110,000–180,000).Footnote 7 However, this shared concern for air power did not bring with it an agreement on strategic bombing. Consensus on that point was undercut by the uneven impact of the war on its participants.
Geography was a key consideration underpinning the evolution of French air doctrine and therefore orders for planes, as well as the differing Anglo-French views on strategic bombing. The heart of the French struggle lay on the western front. As with much of France's war effort, aviation was organized around the army's need to break the impasse of trench warfare and move the war on to German soil. While the army's leadership recognized the growing importance of air power, its perceived utility was primarily as a tactical force to assist battlefield operations. While not denying a place for long-range bombing, its rising cost and poor results combined with the growing demands of the front to reinforce the general staff's view that the needs of the battlefield were paramount. This was reflected in the structure of the air force and the types of planes France's rapidly expanding air industry was producing. In February 1916 the army controlled 1,149 aircraft of which 826 were for observation, 135 fighters, and 188 bombers. Two and a half years later, in August 1918, just over half of the allied air force of 5,508 planes on the western front were French (2,820 aircraft). Of this force 15 percent of France's planes were bombers compared to 22 per cent for Britain and just 8 per cent for Germany.Footnote 8
For the French the over-riding objective was to produce a force that could gain control of the air and thus secure the ability to conduct reconnaissance and tactical bombing. This conception of the combat zone was sufficiently elastic to encompass nearby targets such as rail links, depots, assembly points, and some key industrial centres of production, but it did not include large urban areas far behind enemy lines. France's geostrategic position, across the Rhine from Germany, placed the country's defence in the hands of the army. Their needs set the direction of mobilization; it was their ‘total war’. That course was made clear in 1918 by General Philippe Pétain, commander of the French army, when he described aerial bombing as ‘the direct extension of artillery … all efforts should converge on the essential act: the battle’.Footnote 9 It was a dictum that would prove just as true for France's military during the peace that followed.Footnote 10
The war's geography had other important influences on the development of French air doctrine. A key principle of bombing was that ‘we do not bomb to bomb’ but rather ‘to obtain a precise result’. Isolated attacks offered little since ‘only massive action is susceptible to produce appreciable results’.Footnote 11 When bombing, the ‘first result to seek’ was material destruction, without which any effects on enemy morale were impossible to achieve.Footnote 12 The further away the target, the more difficult it was to maintain the required concentration and tempo of attacks, as shown by French raids against industrial centres along the Rhine early on in the war. The forces available were too weak to provide the intense and continuous level of bombardment considered necessary for success. Short-distance bombing, however, minimized these problems and so held out the potential for considerable destruction of men and matériel.Footnote 13
Therefore the logic of restraint was in part a corollary of the war's geography. German bombers had to travel short distances to strike French cities, often just 30 kilometres. French targets in Germany were located well past the zone of occupation, often 150 to 200 kilometres behind the lines. Bombing a city like Frankfurt was ‘incomparably more difficult for the Allies’ than it was for the Germans to attack Paris, especially because to have any substantive effect, raids needed to be conducted in a ‘massive way and frequently repeated’. This constraint was calculated as giving the French an effective radius of operations of roughly 100 kilometres behind the front.Footnote 14
The commander of French aviation on the western front, General Maurice Duval, encapsulated these views in 1918, when he outlined his scepticism concerning ‘the efficiency and profit of bombing far off regions’.Footnote 15 Fighting ‘chez nous’, France needed a bomber force ten to twenty times larger than Germany's to redress the imbalance caused by the war's geography.Footnote 16 An army study written a year earlier fleshed out this logic. Given the proximity of French cities to the front, German bombing raids on them could, ‘à la rigueur’ be considered legitimate ‘military attacks’. Unfortunately the ‘reciprocal is not true’. A strategic bombing battle required French public opinion to be ten to twenty times stronger than that of Germany. Otherwise the government must not succumb to popular pressure for a dangerous escalation in reprisals.Footnote 17
Bombing areas close to the front was complicated by the presence of French civilians under German occupation. Attacks against important coal and steel installations further behind the lines in Alsace-Lorraine also raised the thorny issue of potential civilian casualties. In 1915, the commander of the French army, General Joseph Joffre, noted that military and industrial targets in the area must be ‘clearly distinguished from civilian agglomerations which never should be reached’ by bombs.Footnote 18 As a key French objective of the war was the return of this territory to France, alienating the local population was politically counterproductive. Nor did the bombing of civilians, particularly French nationals, mesh with the image of France as a defender of civilization against German militarism, particularly given the ongoing propaganda campaign highlighting the atrocities committed by German troops against Belgian civilians during the first weeks of the war.Footnote 19
A key principle of the bombing plan that the army developed in 1916 was that ‘for reasons of a political and moral order’ France renounced attacks on military targets close to civilian centres or the border with Switzerland.Footnote 20 Even in relatively accessible areas like northern France, Belgium, and Luxembourg the civil–military distinction was, on the whole, maintained. This even though the policy often turned to enemy advantage, as illustrated in the case of a German airfield in Belgium that was constructed next to an orphanage run by French nuns.Footnote 21
As the French bomber force increased in strength and plans were developed for its deployment, the question of what to do about German cities became acute. For most of the conflict, attacks against enemy urban centres were justified only in response to the bombardment of French cities. These ‘reprisal raids’ were conducted in the hopes of deterring an escalation in the air that would lead to a strategic bombing war against civilians. Given geography and German air power, such an expansion could only work against France. To prevent further escalation, French reprisals were carefully calibrated. The size of the city was generally that of the one Germany had attacked. The French also publicized the reason for their raids. Like carrots and sticks, pamphlets justifying the attack accompanied the bombs that delivered it.Footnote 22 Underpinning this approach was the assumption that by bringing the war to German civilians, they would clamour for their government also to distinguish between the civilian and the military.Footnote 23 The ‘material and especially moral’ damage caused by these attacks was supposed to prevent a renewal of German raids. The more secure behind the lines the population of a city thought it was, the greater the impact of the attack. The disruptions caused by the raids also reduced industrial production, a ‘happy consequence in this war in which matériel plays such a great role’.Footnote 24
While the army was focused on the tactical uses of bombing, it did not exclude targets away from the battlefield. From heavy industry to railway stations there were many objectives that were seen as crucial to the enemy war effort, regardless of their proximity to the front lines. In response to German attacks on French cities, in October 1916 the army was allowed to raid factories, railway stations, and military installations inside German urban centres. This decision, however, was reversed in March 1917, a policy confirmed by the incoming war minister, Paul Painlevé. Only reprisal attacks were allowed and solely with express, case by case, approval from the government.Footnote 25
This restriction was added to the interdictions already in place by the end of 1916, by which time military targets in Luxembourg and Lorraine (primarily blast-furnaces), Alsace, Belgium, and along the Swiss border all had to be justified in detail. That included outlining the separation between the target and any surrounding civilian population. The only areas in occupied France open to attack were in and around the front.Footnote 26
The government's decision of March 1917 to have final authority over reprisal raids was quickly contested. Two months later the army warned the war minister of the problems engendered by waiting for his approval before launching a reprisal attack. The process inevitably delayed the French reply and risked its cancellation, sine die, if weather conditions deteriorated. In order to ensure an ‘instantaneous riposte’, a list was drawn up of French cities, and the corresponding German city to be subjected to ‘reprisal’. This pre-approved, and thus automatic, policy and the target list were authorized by Painlevé on 23 September 1917. Because of diminishing German attacks, however, the French government did not carry out a représaille against Germany after 1 November 1917. Between 1 January 1916 and 1 November 1917 the army had conducted just thirty-nine reprisal raids against eleven German cities.Footnote 27
While the military command pressured the war minister to regain control over reprisals, it in turn had to handle the misgivings of its subordinates. It was far from easy to uphold the restrictions on where and when to bomb. Incentives, like the Michelin prize, a bonus for aviators who dropped the greatest number of bombs on the enemy, risked undermining official policy.Footnote 28 This compounded a problem that Joffre had been forced to address in 1915: the attack of targets not listed in the bombing plan. Unauthorized attacks occurred although he had ‘formally proscribed’ the bombing of locations that had not been authorized or were not ‘enemy troops’. Whether by error, or simply from a desire to make the most of a mission gone wrong, such incidents reaffirmed the need for operations to conform to their design, and orders.Footnote 29 As French air power grew, so did the circumscription of what constituted a legitimate target and the temptation for bombers to ‘go it alone’.
Pilots chafed over the growing list of restrictions. Requests from flying officers for permission to conduct reprisal raids against Berlin, Hamburg, Cologne, and even Constantinople, were repeatedly turned down by the army command. Usually this was because a large enough force could not be assembled but, ironically, in other instances it was because the risk of provoking an escalation was judged too high.Footnote 30
The push for an expansion of reprisal raids also came from the sea. The growing German submarine campaign against neutral and allied shipping raised the possibility of treating the sinking of vessels as the equivalent of attacks against cities, thus warranting représailles. This prospect launched a series of discussions that included the navy minister, the army leadership, and the government. Again, the importance of not dislocating French bombing doctrine was clear, as were arguments against taking scarce resources away from attacks against ‘essential objectives’ directly connected to the ground war. War Minister Hubert Lyautey refused to change the army's bombing plan. Instead he decided to split the difference by allowing raids against existing targets to be proclaimed as reprisals for specific acts of ‘piracy’ by German submarines.Footnote 31
Perhaps the strongest French source of pressure for the opening of a strategic bombing front came from politicians outside the government. A key member of this movement was Pierre-Étienne Flandin, a well-known député who would hold the aviation portfolio in several post-war governments. As Flandin told Premier Georges Clemenceau at the end of 1917, air raids against enemy factories and cities were the ‘only resource’ left ‘to make the German people feel the weight of the war’. Such a campaign would destroy production and ‘reach the morale’ of German civilians by ‘letting them know the horrors of war’. To carry out this mission, he proposed the creation of a massive strategic bomber force of 4,000 planes under American command.Footnote 32 Various parliamentary commissions also lobbied the government and army for a greater, and more efficient, investment in bombing, particularly against enemy industry.Footnote 33 Despite these internal pressures during the war, French bombing policy and resources remained centred on the front.
France was not the only member of the alliance to adopt this position. Italy also feared coming out the loser in a strategic bombing contest. In May 1918 General Luigi Bongiovanni, the commander of Italy's military aviation, told the Inter-Allied Aviation Committee (IAAC), responsible for co-ordinating allied air strategy, that the ‘bombing of open cities is more a political action than a military one’. Given the relative ‘vulnerability’ of allied cities and a lack of planes, a postponement of the construction of an inter-allied force was the most logical course.Footnote 34 As with his French counterparts, he held that geography and limited resources worked against an immediate build up of strategic bombing. Being aware of the increasing linkage between the military and civilian fronts did not mean launching a strategic bombing campaign, and thus opening up a two-front war.
II
This continental logic was not to be found in Britain. There, the same factors to be found in France combined in a dissimilar way to produce the opposite result. In 1917 ‘two uncoordinated strategic [bombing] campaigns’ were conducted by the German army and navy, particularly against London, and triggered a different calculation of deterrence and the civil–military linkage. While the German attacks were costly and did not achieve a ‘decisive success’ they did insure a rapid British escalation towards the strategic bombing of Germany, including its cities.Footnote 35
Shortly after the war began, Britain confronted German zeppelin attacks, some against targets inside cities. Even before the attacks, the Royal Naval Air Service (RNAS) had acquired the responsibility of not just protecting the country against air raids but also going on the offensive, in particular by bombing zeppelin bases. The RNAS continued to develop its efforts at strategic bombing, and by 1916 was attacking German cities from bases in France. The renewed German attacks of 1917 caused little damage, but much public outrage and demands for action. Most importantly, the bombings came at a time of grave concern inside the British government over the state of public morale after the unprecedented costs of three years of war. Yet the cabinet's response was very different from that of France, in no small part thanks to institutional politics. In 1916 it had reassigned air defence to the army's Royal Flying Corps (RFC). In the wake of the 1917 German attacks the government chose to make aviation a top priority and establish a long-range bombing force to attack Germany. In doing so Prime Minister David Lloyd George largely set aside the concerns of the army and navy. A year later the RAF was created with responsibility for both strategic bombing and home defence.Footnote 36
An independent and specialized force, which in 1918 became the Independent Force (IF), was quickly established. Based in France, its purpose was to attack German military and industrial targets, including those found in cities. One of the key assumptions behind this approach was that aircraft production would quickly provide a surplus that could be redeployed to strategic bombing. The pioneer of British bombing was General Hugh Trenchard, who would lead the post-war RAF. For much of the war he was an RFC officer in the French mould, convinced that air power should be focused on the terrestrial front and in support of the army. While this augured badly for his command of the IF, Trenchard's views were undergoing a radical change, in part because, as with the RNAS, the bombing mission attracted governmental support. He became a vociferous advocate of attacking civilian morale. However, his doctrine was not simply aimed at garnering the support of his superiors in London but the French military as well. For if the allies agreed on anything about bombing, it was that attacks could be successful only if they had the tremendous resources needed to attain great intensity and frequency.Footnote 37
Trenchard's eager embrace of strategic bombing was clearly displayed to the French in notes he wrote that were provided to allied delegations for a meeting of the IAAC in July 1918. His point of departure was that air raids against Germany were not reprisals. Instead, ‘the word “reprisal” should be removed from the military vocabulary’. ‘From the military point of view’, these were operations against ‘military objectives’ and ‘civilian morale’, as important as ‘those of the infantry’. Trenchard rejected any restraint in bombing policy. Attempts to reach an agreement with Germany on the use of bombing or simply to threaten systematic reprisals would be calamitous. Allied bombing power was rapidly becoming an important force for victory. To give it up made as much sense as for Germany to forego its advantage in submarine warfare.Footnote 38
Trenchard's strategic bombing doctrine was built on several important assumptions. It presumed frequent long-distance bombing by large groups of aircraft and the required specialized equipment and training, all housed in a separate, specialized, organization. For strategic bombing to be effective, particularly during daytime, air superiority was more important than ever. Trenchard also assumed that bombers would be of ‘more considerable value’ in attacking Germany than employed in raids on the front that offered only diminishing returns.Footnote 39
The chief of the air staff, Major-General Sir Frederick Sykes, defended this view to the IAAC in July 1918, as he pushed for the creation of an allied bomber force based on the IF. Sykes argued that strategic bombing constituted a new type of warfare, distinct from naval and army operations. It would follow a clearly laid out plan of attack against ‘military, industrial, and morale’ objectives in Germany. Sykes adamantly opposed discussions with the Germans for a joint cessation of raids against cities. He rejected using the allies' superior bombing capability to wrest larger concessions from the enemy. Even if Germany agreed to end bombing operations outside the ‘zone of combat’ and ceased its campaign of submarine warfare, it could not be counted on to respect its engagements. They had ‘ignored the laws of war and would violate its promises’, once the allied aviation programme was allowed to lapse beyond reprise. The only argument for negotiations was the potential for German reprisals. Here Sykes turned French thinking on its head. Germany could not inflict the same amount of damage on allied military production as it would suffer from an inter-allied bombing force. German munitions manufacturers were ‘congested’ around Düsseldorf and Essen while allied factories were dispersed across two continents. Furthermore, defending against an expanding allied bombing force would oblige Germany to withdraw units from the front to key sites inside its borders. Like Trenchard, Sykes demanded a strategic inter-allied air arm tasked to destroy the essential aspects of the home front – particularly military production, transport, and civilian morale.Footnote 40
The French critique of this position was utilitarian and total, foreshadowing many of the problems strategic bombing would encounter during the Second World War. Britain might be correct in assuming a measure of air superiority over Germany; however, its 160 kilometre front was nothing compared to the 600 held by France. French logic demanded a redeployment of any excess British forces to assist their ally. The idea that applying a growing bomber force against the military front would prove an investment with ever diminishing returns was rejected. German train traffic to the battlefield had not yet been effectively interrupted. Continuous bombing had not rendered enemy depots and encampments ‘uninhabitable’. This lack of success increased the further behind the front one went. Since repeated and intense attacks were essential for effective bombing, Trenchard's vast programme required more than ten times the aircraft he had calculated and was therefore an impossibility. To target civilian morale was equally erroneous. Footnote 41 While Trenchard argued that in bombing ‘the morale effect at present is far greater than the material effect’Footnote 42 the French view was just the opposite. The morale advantages that came from bombing depended upon physical destruction and so ‘the material efficiency of bombardments is therefore, in all cases, the first result to seek’.Footnote 43 There should be no ‘illusions about the importance of the morale effect’ of bombing raids on Germans. Even if extensive destruction was achieved, German discipline was such that it could never cause ‘serious consequences’, especially since the government would use ‘the means necessary’ to maintain a well-ordered society.Footnote 44 As Duval told Trenchard, German raids against London and Paris had ‘exercised no influence’ on the course of the war.Footnote 45 Whatever the potential of strategic bombing, its current capability was limited. It must be focused on the front and closely related military targets.
The French rejection of strategic bombing in many ways mirrored another Franco-British battle of 1918: the one over manpower. The spring offensives launched by Germany brought the conflicting French and British views on how best to use this scarce resource to a crisis point. As with the debate over strategic bombing, France argued that the praetor optimal mobilization of the war effort required that it be organized around the immediate demands of the military front. In their view, British manpower and resources were inefficiently focused on often relatively comfortable tasks well behind the trenches, like shipping. Given the desperate need for troops on the western front, the British push for a strategic bombing force was typical of what the French saw as a larger strategy that in the end sacrificed allied efficiency and a great deal of French blood. The British response to these criticisms was often a model of logic and should not be underestimated. For example, transport was essential to the war effort and the exploitation of Britain's comparative advantage in shipping only increased the efficacy of the allied cause. That said, national self-interest and post-war considerations were also at play.Footnote 46 The pursuit of strategic bombing dovetailed with British arguments and policies for not just a general mobilization and mechanization but one of comparative advantage that favoured investing in the manufacturing resources and manpower of Britain more than France. In many ways, Britain's aviation strategy was the same as its naval strategy.
By 1918 the aviation industry in both countries had grown to become both a major employer of skilled labour and consumer of resources. However, the arrival of the manpower crisis highlighted the two countries' very different ‘total war’ calculations for air power. Under French pressure Lloyd George allowed a French expert, Lieutenant Colonel Albert Rouré, to come to Britain and study the country's allocation of manpower. Rouré found extensive overstaffing and inefficiency, including in the aeronautical sector. According to his report, British aviation employed 214,000 men while France's even larger force required only 100,000. Lloyd George acknowledged to Clemenceau at the end of August that among the growing demands on British resources was aviation, leaving even less in the way of additional infantry for the western front. This Anglo-French debate over manpower underscores just how far Britain, at a critical juncture, continued to invest scarce resources in aviation, and in particular strategic bombing. Rouré's report emphasized the French model and attendant calculus of mobilization, one in which the limited resources available were organized to the greatest possible degree around the immediate human and material demands of the front.Footnote 47 The French calculation was that even with its greater efficiency in aviation, important constraints, like manpower, obviated investing in strategic bombing.
Lloyd George's calculation of strategy and economics was very different. To the extent possible British manpower's role on the military front would be minimized and, in part through mechanization, the production of war-winning ships, aircraft, and munitions would be maximized. Britain would transport American soldiers to the front and lead the strategic bombing force being developed to strike a decisive blow against German production and morale in 1919. As the war cabinet's War Priorities Committee put it in September 1917, aviation programmes ‘should have priority after shipbuilding … [and] were sufficiently important to justify the reduction in the output of other munitions such as shells and rails’. It was a view reinforced by Munitions Minister Winston Churchill a month later.Footnote 48
These differing French and British strategies over long-range bombing did not destroy Anglo-French co-operation on the western front. There was a modus vivendi between the British commander, Field Marshal Douglas Haig, and Pétain, since both sought to keep military aviation under army control, and focused on the army's immediate needs. The joint desire to attack objectives like enemy aerodromes, rail links, and smelters, greased the sometimes squeaky wheels of allied co-operation.Footnote 49
Ultimately the growing mobilization and strengthening of air power in both countries combined with the widening divide in air doctrines to lead to important differences in the use of military aviation. The early success of the spring 1918 German offensives brought this problem to a head, as the need for Anglo-French co-operation clashed with conflicting priorities for bombing. The battlefield emergency helped to bring about a new level of co-ordination as General Ferdinand Foch became the generalissimo of allied forces on the western front. Given Foch's scepticism towards strategic bombing this unification of command raised doubts as to its place in allied strategy. In July the IAAC, meeting for only the third time, was host to a fierce Anglo-French struggle over the utility of an inter-allied strategic bombing force and what ends it should pursue. In the end Foch had his way. Trenchard's IF was expanded, but, under the new scheme, he would report to Foch and not the Supreme War Council, the ultimate allied body responsible for the prosecution of the war. The creation of an Inter-Allied Independent Air Force was finalized by the allied governments on 3 October 1918, five weeks before the end of the war. Bombing operations would be organized around the needs of the military front. As its founding document stated, ‘during periods of active operations’, the ‘requirements of battle will have to be met first’. Only during ‘steady or quiet periods’, when the needs of the combat zone had been ‘satisfied’, could the full weight of the bomber force be directed on longer-distance raids.Footnote 50
The bombing plan for Germany that was drawn up for Trenchard's force and approved by Foch underscored the French view. The key objectives were industrial and commercial sites as well as the railway system. ‘Morale’ bombing was relegated to the margins. As was the case with the inter-allied bombing force, the adoption of British positions on reprisal raids did not change France's underlying policy. Nor does it appear to have made a fundamental difference in Trenchard's approach to bombing given his lack of resources and the shared concern for targets like enemy aerodromes.Footnote 51
During the drafting of the plan in August, the French moved towards a British definition of reprisal attacks. A preliminary version noted that the term ‘représailles’ posed a serious disadvantage. If the enemy ceased its raids on allied cities, there would no longer be a justification for reprisals. That meant ‘renouncing the bombardment of large train stations and factories’ found inside German cities, which were impossible to conduct without causing damage to the surrounding suburbs. The solution was to adopt the British justification and definition for bombing urban centres. The RAF laid the blame for this necessity on the German decision to attack ‘open cities’ under the ‘pretext of reaching military objectives’. With the front receding towards Germany and the danger of large-scale German attacks against allied civilians diminishing, many of the earlier French calculations no longer added up. That, however, did not release a desire to invest in large-scale operations aimed at destroying German morale. The military and civilian fronts were still to remain, as much as possible, distinct. As the final version of the bombing plan stated, raids ‘on the German population do not properly speaking constitute reprisals’. Like poison gas, the bombing of cities was first employed by Germany and ‘we are therefore forced to use in our turn’, yet the plan remained a palimpsest of French doctrine, because military, industrial, and transport targets remained the key objectives.Footnote 52
The inter-allied bombing force created at the end of the war combined strategic expansion and restraint. While attacking ever deeper behind enemy lines, it was not to bring its weight to bear on civilian centres and so lose sight of the battlefield. Foch decided which types of targets were to be struck, even if in practice Trenchard retained considerable control over British operations. To a surprising extent when it came to bombing, France retained a division between the military and home fronts.
III
The evolution of French strategic bombing highlights three important aspects of restraint in the context of ‘total war’. First, the diversity that came with escalation and limited resources. France and Britain, large modern industrial democracies fighting together, shared a growing commitment to the development of air power. Yet that common capability was not enough to overcome differing political, geographic, strategic, and institutional calculations. By the end of the war Britain had laid a firm foundation for its post-war programme of strategic bombing. It was based on its capability to bring down the home front, and thus eliminate the civil–military divide, as epitomized in Trenchard's heralding the ‘morale’ effects obtained by the IF. In theory and practice, ‘reprisal’ gave way to ‘military necessity’. In contrast, France ended the war with a doctrine that was focused on the battlefield although it increasingly encroached on the home front. France's eventual willingness to adopt the British logic of necessity did not end the practice of maintaining barriers between military and civilian targets that they had slowly codified during the war. France's post-war military aviation evolved along rather different lines from that of the RAF. For the first decade after the war, there was no separate air force. France did not put in place a strategic bomber force and air defence system like that of the RAF.Footnote 53
When war returned in 1939 differing constraints and mobilizations reversed Anglo-French disagreements over bombing. The British insisted that the allies scrupulously respect a policy of bombing a very narrow set of military targets. Only objectives ‘that will render the war shorter’ were authorized for bombing ‘since we do not have the intention of attacking the civilian population’. The dangers of German air power and the consequent costs of escalation and reprisals against Britain, especially London, merged with concerns over alienating public opinion in neutral countries and Nazi Germany. Perhaps most importantly, expanding the list of objectives seemed to offer few immediate advantages given the bomber force in existence. Britain's embrace of a restraint that would ‘restrict bombardment more severely than is required by a reasonable interpretation of existing international law’ would soon give way to the bomber offensive as events and further mobilization reversed this calculus. Conversely, while the French military pressured the British to channel their aviation effort into tactical support for the allied forces on the continent, France also contemplated an extraordinarily ambitious, unrestrained, and reckless strategic air operation. The government considered bombing Baku in the hopes of destroying a key source of Germany's oil, albeit at the risk of provoking a war with the Soviet Union.Footnote 54 These early and rapid gyrations in bombing policy underscore how the decision to engage in a strategic campaign that would subsume civilians was far from ordained.
Second, many studies of wartime restraint treat it as a decision to forgo a potential advantage, which requires co-operation with the enemy.Footnote 55 Much of the French calculation of restraint was based on the assumption of co-operation, but in the last months of the war, as fear of German attacks against allied cities diminished, so did the need to seek it. That made clear the importance of efficiency in French thinking; the idea that battlefield-centred bombing was the most effective application of aerial bombardment but that, relative to other forces being mobilized, it was not a top priority. Right to the end of the war, despite British pressure to back Trenchard's approach à outrance, the French continued to argue for the maintenance of their approach, and a considerable distinction between an expanding set of military targets and civilians. The logic of French restraint was not necessarily that of co-operation, with friend or foe. As with Britain, it came in large part from the way France mobilized its air power, and its country.
Finally, in the context of an unprecedented mobilization of modern society, it has been easy for scholars, particularly those tracing the connections forged between military and home fronts, to lose sight of the importance of the war's limits. As the conflict expanded so too did its needs, thereby making it almost impossible for supply to match demand. Limitations are a key to understanding France's restraint. French and British calculations were based on civil–military accountancies of costs and benefits that were heavily influenced by the need to make the most of scarce, insufficient, resources. At the heart of the French critique of the British commitment to bombing were the inadequate means available for it to be effective. Nor was France able to muster the bomber force, ten times Germany's, it felt was required to make anything more than reprisals worthwhile. ‘Total war’ has been presented as complete national mobilization, an ‘ideal type’, that countries raced to attain.Footnote 56 French restraint in strategic bombing illustrates the inverse: how mobilization did not go down certain roads because geography, contingency, limits, and attendant choices, favoured intensifying the war elsewhere. It is a vision of modern war that, unlike the excellent Chickering and Förster series, goes beyond 1945.
