On 16 March and then on 29–30 March the Allies launched the most destructive attacks of all on Sofia, as well as subsidiary attacks on Burgas, Varna, and Plovdiv in the interior, designed to disrupt rail communications and sea traffic for the Turkish trade with Germany. The attacks were aimed predominantly at the administrative city centre of Sofia and carried a proportion of incendiaries, 4,000 in all, in order to do to Sofia what had been done so effectively to German targets. The raid of 16 March burned down the royal palace; the heavy raid of 29–30 March by 367 B-17s and B-24s, this time carrying 30,000 incendiaries, created a widespread conflagration, destroying the Holy Synod of the Bulgarian Orthodox Church, the National Theatre, several ministries and a further 3,575 buildings, but killing only 139 of the population that had remained.26 The last major raid, on 17 April by 350 American bombers, destroyed a further 750 buildings and heavily damaged the rail marshalling yard. During 1944 the death toll in Sofia was 1,165, a figure that would have been considerably higher had it not been for the voluntary evacuation of the capital. The incendiary attacks hastened the disintegration of Bulgarian politics and increased support for the Soviet Union, whose armies were now within striking distance. But only on 20 June 1944, several months after the bombing, did the new government of Ivan Bagryanov begin formal negotiations for an end to Bulgarian belligerency, still hoping to keep Bulgaria’s territorial spoils and avoid Allied occupation.27 By this time the Allies had lost interest in bombing Bulgaria, which slipped further down the list of priority targets as the bombers turned their attention to Budapest and Bucharest in the path of the oncoming Red Army.28
By the summer of 1944 the Allies had other preoccupations and it seemed evident that Bulgarian politics had been sufficiently destabilized by the bombing to make further attacks redundant. Nevertheless, the final assessment of the effects of the bombing was ambivalent. In July the United States Joint Chiefs of Staff prepared an evaluation of the Balkan bombings which suggested that the psychological effects desired had largely been achieved; the report nevertheless suggested that the enemy had sustained an effective propaganda campaign about the high level of civilian casualties, which had undermined the prestige of both the United States and Britain in the eyes of the Bulgarian people. The chiefs directed that in the future any attacks in the region had to be confined to ‘targets of definite military importance’ and civilian casualties minimized. The British chiefs of staff rejected the American claim and, in defiance of what they well knew to be the case, insisted that only military targets had been subject to attack, even if this had involved damage to housing and civilian deaths. Their report concluded that Allied bombers ought always to be able to act in this way and that operations ‘should not be prejudiced by undue regard for the probable scale of incidental casualties’.29 This was a view consistent with everything the RAF had argued and practised since the switch to the deliberate bombing of German civilians in 1941.
For the historian the judgement is more complex. Bombing almost certainly contributed to the collapse of any pro-German consensus and strengthened the hand both of the moderate centre-left in the Fatherland Front and of the radical partisan movement. But in the end this did not result in a complete change of government until 9 September 1944, when the Soviet presence produced a Fatherland Front administration dominated by the Bulgarian Communist Party (a political outcome that neither Churchill nor Eden had wanted from the bombing).30 Moreover, other factors played an important role in Bulgarian calculations: the crisis provoked by Italian defeat and surrender in September 1943; the German retreat in the Soviet Union; and fear of a possible Allied Balkan invasion or of Turkish intervention.31 Where Churchill saw bombing as a primitive instrument for provoking political crisis and insisted throughout the period from October 1943 to March 1944 that this was the key to knocking Bulgaria out of the war, the American military chiefs continued to give preference to the bombing of Italy and Germany and were less persuaded that a political dividend was certain. For them the bombing fitted with the strategy of wearing down Germany’s capacity for waging war by interrupting the supply of vital war materials and forcing the diversion of German military units from the imminent Normandy campaign. There was also a price to pay for the bombing. In September 1944, following the Bulgarian surrender, some 332 American Air Force prisoners of war were sent by air shuttle to Istanbul and then on to Cairo; some had crashed bombing Bulgaria, others on their way to or from attacks on Romanian targets. An American report suggested that the prisoners had been badly treated. Two air force prisoners were killed by the Bulgarian police, and an estimated 175 American war dead were presumed to be on Bulgarian territory, although only 84 bodies could be located.32
The bombing of Bulgaria recreated in microcosm the many issues that defined the wider bombing offensives during the Second World War. It was a classic example of what has come to be called ‘strategic bombing’. The definition of strategic bombing is neither neat nor precise. The term itself originated in the First World War when Allied officers sought to describe the nature of long-range air operations carried out against distant targets behind the enemy front line. These were operations organized independently of the ground campaign, even though they were intended to weaken the enemy and make success on the ground more likely. The term ‘strategic’ (or sometimes ‘strategical’) was used by British and American airmen to distinguish the strategy of attacking and wearing down the enemy home front and economy from the strategy of directly assaulting the enemy’s armed forces.
The term was also coined in order to separate independent bombing operations from bombing in direct support of the army or navy. This differentiation has its own problems, since direct support of surface forces also involves the use of bombing planes and the elaboration of target systems at or near the front whose destruction would weaken enemy resistance. In Germany and France between the wars ‘strategic’ air war meant using bombers to attack military and economic targets several hundred kilometres from the fighting front, if they directly supported the enemy’s land campaign. German and French military chiefs regarded long-range attacks against distant urban targets, with no direct bearing on the fighting on the ground, as a poor use of strategic resources. The German bombing of Warsaw, Belgrade, Rotterdam and numerous Soviet cities fits this narrower definition of strategic bombing. Over the course of the Second World War the distinction between the more limited conception of strategic air war and the conduct of long-range, independent campaigns became increasingly blurred; distant operations against enemy military, economic or general urban targets were carried out by bomber forces whose role was interchangeable with their direct support of ground operations. The aircraft of the United States Army Air Forces in Italy, for example, bombed the monastery of Monte Cassino in February 1944 in order to break the German front line, but also bombed Rome, Florence and the distant cities of northern Italy to provoke political crisis, weaken Axis economic potential and disrupt military communications. The German bombing of British targets during the summer and autumn of 1940 was designed to further the plan to invade southern Britain in September, and was thus strategic in the narrower, German sense of the term. But with the shift to the Blitz bombing from September 1940 to June 1941, the campaign took on a more genuinely ‘strategic’ character, since its purpose was to weaken British willingness and capacity to wage war and to do so without the assistance of German ground forces. For the unfortunate populations in the way of the bombing, in Italy or in Britain or elsewhere, there was never much point in trying to work out whether they had been bombed strategically or not, for the destructive effects on the ground were to all intents and purposes the same: high levels of death and serious injury, the widespread destruction of the urban landscape, the reduction of essential services and the arbitrary loss of cultural treasure. Being bombed as part of a ground campaign could, as in the case of the French port of Le Havre in September 1944 or the German city of Aachen in September and October the same year, produce an outcome considerably
worse than an attack regarded as strategically independent.
In The Bombing War no sharp dividing line is drawn between these different forms of strategic air warfare, but the principal focus of the book is on bombing campaigns or operations that can be regarded as independent of immediate surface operations either on land or at sea. Such operations were distinct from the tactical assault by bombers and fighter-bombers on fleeting battlefield targets, local troop concentrations, communications, oil stores, repair depots, or merchant shipping, all of which belong more properly to the account of battlefield support aviation. This definition makes it possible to include as ‘strategic’ those operations that were designed to speed up the advance of ground forces but were carried out independently, and often at a considerable distance from the immediate battleground, such as those in Italy or the Soviet Union, or the aerial assault on Malta. However, the heart of any history of the bombing war is to be found in the major independent bombing campaigns carried out to inflict heavy damage on the enemy home front and if possible to provoke a political collapse. In all the cases where large-scale strategic campaigns were conducted – Germany against Britain in 1940–41, Britain and the United States against Germany and German-occupied Europe in 1940–45, Britain and the United States against Italian territory – there was an implicit understanding that bombing alone might unhinge the enemy war effort, demoralize the population and perhaps provoke the politicians to surrender before the need to undertake dangerous, large-scale and potentially costly amphibious operations. These political expectations from bombing are an essential element in the history of the bombing war.
The political imperatives are exemplified by the brief aerial assault on Bulgaria. The idea of what is now called a ‘political dividend’ is a dimension of the bombing war that has generally been relegated to second place behind the more strictly military analysis of what bombing did or did not do to the military capability and war economy of the enemy state. Yet it will be found that there are many examples between 1939 and 1945 of bombing campaigns or operations conducted not simply for their expected military outcome, but because they fulfilled one, or a number, of political objectives. The early bombing of Germany by the Royal Air Force in 1940 and 1941 was partly designed, for all its military ineffectiveness, to bring war back to the German people and to create a possible social and political crisis on the home front. It was also undertaken to impress the occupied states of Europe that Britain was serious about continuing the war, and to demonstrate to American opinion that democratic resistance was still alive and well. For the RAF, bombing was seen as the principal way in which the service could show its independence of the army and navy and carve out for itself a distinctive strategic niche. For the British public, during the difficult year that followed defeat in the Battle of France, bombing was one of the few visible things that could be done to the enemy. ‘Our wonderful R.A.F. is giving the Ruhr a terrific bombing,’ wrote one Midlands housewife in her diary. ‘But one thinks also of the homes from where these men come and what it means to their families.’33
The political element of the bombing war was partly dictated by the direct involvement of politicians in decision-making about bombing. The bombing of Bulgaria was Churchill’s idea and he remained the driving force behind the argument that air raids would provide a quick and relatively cheap way of forcing the country to change sides. In December 1943, when the Mediterranean commanders dragged their feet over the operations because of poor weather, an irritated Churchill scribbled at the foot of the telegram, ‘I am sorry the weather is so adverse. The political moment may be fleeting.’ Three months later, while the first Bulgarian peace feelers were being put out, Churchill wrote ‘Bomb with high intensity now’, underlining the final word three times.34 The campaign in the Balkans also showed how casually politicians could decide on operations whose effectiveness they were scarcely in a position to judge from a strategic or operational point of view. The temptation to reach for air power when other means of exerting direct violent pressure were absent was hard to resist. Bombing had the virtues of being flexible, less expensive than other military options, and enjoying a high public visibility, rather like the gunboat in nineteenth-century diplomacy. Political intervention in bombing campaigns was a common feature during the war, culminating in the decision eventually taken to drop atomic weapons on Hiroshima and Nagasaki in August 1945. This (almost) final act in the bombing war has generated a continuing debate about the balance between political and military considerations, but it could equally be applied to other wartime contexts. Evaluating the effects of the bombing of Bulgaria and other Balkan states, it was observed that bombing possessed the common singular virtue of ‘demonstrating to their peoples that the war is being brought home to them by the United Nations’.35 In this sense the instrumental use of air power, recently and unambiguously expressed in the strategy of ‘Shock and Awe’, first articulated as a strategic aim at the United States National Defense University in the 1990s and applied spectacularly to Baghdad and other Iraqi cities in 2003, has its roots firmly in the pattern of ‘political’ bombing in the Second World War.
Bombing was, of course, much more than a set of convenient political tools and much of what follows describes the organizations, the forces and the technology that made bombing operations possible. Strategic bombing was a military activity which had to be organized very differently from operations of the army and navy and it was one fraught with difficulty under the technical conditions of the time. Air force commanders wanted to deliver what the politicians wanted, but as a consequence bomber forces were always trying to run before they could walk. All the major air services faced a long learning curve during the war as they struggled to overcome a whole range of inherent problems and limitations. Power was generally projected onto distant cities or industrial installations and in most cases involved long and hazardous flights, hampered by fickle weather, by enemy defences, and by complex issues of navigation and effective bomb-aiming. Fixed bases had to be secured near enough to enable the bombing to take place. The rate of loss of aircrew was high, though not exceptional if a comparison is made with other front-line forces. The most distinctive feature of bomber operations was the capacity of aircraft to penetrate enemy airspace and to inflict damage on the domestic economy, military capability and population according to the prevailing directives. No other service could project power in this way, so by default the bomber became the supreme instrument for waging what was defined at the time as total war. The belief that modern, industrialized war was now to be fought between whole societies, each mobilizing the material energies and willpower of their entire population for the task of fighting, arming and supplying the mass armed forces of the modern age, took root in the generation that grew up after the Great War. While it was generally understood by the air forces themselves that bombing enemy populations for the sake of exerting terror was contrary to conventional rules of engagement, attacking and killing armaments workers, destroying port facilities or even burning down crops could all be construed, without too much sophistry, as legitimate objectives of total war.
Before the coming of the Second World War those air forces that had considered the implications of war against the enemy home front had to choose a set of targets which made strategic sense. These included all military installations, heavy industry, energy supply, armaments production and communications. The German campaign against Britain was based on a detailed gazetteer of industrial and military targets scrupulously compiled before 1939 from photo-reconnaissance evidence and industrial intelligence.36 In the summer of 1941 the United States Army Air Forces drew up a plan for bombing Germany that identified six key target systems and a total of 154 individual industrial targets, whose destruction was supposed to lead to the collapse of the German war economy and its supporting services.37 Air force commanders were reluctant to endorse operations that could not demonstrate some clear military or war economic purpose, however broadly the net of total war might be sprea
d, or however forceful the political pressure. Even in Bulgaria, the brief political directive from Churchill was watered down when it was passed on to the military chiefs to give it a spurious military justification: ‘Sofia is a centre of administration of belligerent government, an important railway centre, and has barracks, arsenals and marshalling yards.’38 The reluctance of the air commanders on the spot to carry out the bombing of Bulgaria with the single-mindedness demanded by Churchill, reflected their view that bombing was not likely to achieve very much in practical terms, while the bombing of, for example, Romanian oil supplies or the Viennese aircraft industry would clearly have significant consequences. The short campaign against Bulgaria illustrated the tension that existed between the exaggerated expectations of politicians and public about the likely political and psychological results from attacking an enemy from the air, and the demonstrable value of doing so in military and economic terms. This ambiguity underlay many of the wider wartime arguments between politicians, airmen and the military chiefs over what bombing could or could not deliver and it helps to explain a feature characteristic of all bombing campaigns: the escalation of the degree of indiscriminate damage.
The pattern of bombing in Bulgaria, from a limited raid on the railway facilities and the Vrajedna airfield in November 1943 to the final raids in March and April 1944 when the extensive use of incendiaries produced much higher levels of urban destruction, was not an accidental progression. In all the major campaigns in Europe (and in the campaigns mounted in eastern Asia) there occurred an evident escalation the longer the bombing went on and the more uncertain were its results. Air force commanders had an urgent need to demonstrate that their operations were militarily useful in the face of hostile criticism from the other services or the impatience of their political masters. This was true of the German bombing of British cities, the British bombing of Germany in 1940–42 and the Combined Bomber Offensive between 1943 and 1945. Perhaps the best example is the shift in British planning from the 1939 Western Air Plans for limited attacks on Ruhr industrial installations to the decision taken in 1941 to attack the central areas of German industrial cities with large quantities of incendiaries to destroy working-class housing and to kill workers. The reasons for escalation – the phenomenon that explains the exceptional or disproportionate level of civilian deaths in all bombed states – differ in historical detail from case to case. Nevertheless they suggest a common process dictated partly by technical frustration at poor accuracy and navigation or high losses; partly by political frustration at the absence of unambiguous results; partly by air force anxiety that failure might reflect badly on its claim on resources; and finally, and significantly, by the slow erosion of any relative moral constraints that might have acted to limit the damage to civilian targets. Among the many questions about the military conduct of the campaigns, the issue of escalation and its consequences remains the most important. It has significant implications for the current exercise of air power in the wars of the twenty-first century.
The Bombing War: Europe 1939–1945 Page 3