2003 History Conference - Air War Europe
First Solo: Air Strategy in Europe in the Second World War
Alan Stephens
When the First World War started in August 1914, air services belonged to armies and navies; to the extent that air doctrine existed it was concerned with reconnaissance and artillery observation in support of surface operations. But by the end of the war four years later, almost every role performed by air power during the most successful air campaign in history – the 1991 Gulf War – had emerged, albeit in a sometimes primitive form.[1] For armies, roles such as close air support, airlift, reconnaissance, communications, interdiction, artillery spotting, resupply, and rescue had made the aeroplane an indispensable contributor to continental strategy. Many of those same roles were repeated in support of maritime strategy, in addition to anti-submarine warfare, convoy escort, search and rescue, maritime strike, and minefield survey.[2]
However, in the minds of airmen at least, other roles had assumed priority. Once pilots started shooting at each other to try to prevent reconnaissance, control of the air had become a prerequisite for all air activities. Consequently, specialist fighter aircraft quickly proliferated. When those aircraft then started to use their enhanced performance and offensive capabilities to increasing effect against surface targets, another compelling reason to gain control of the air existed.
Few events during the First World War caused more panic and alarm than the attacks on London in the middle of the day by German Gotha bombers in mid-1917. As a direct result of those attacks, within three months the British Government had established what amounted to a strategic bombing unit in France, known as the Independent Force, to conduct reprisal raids against the German homeland; within a year the Royal Air Force had been formed as the world’s first separate air force.[3]
The establishment of the Independent Force did more than simply formalise the notion of air strike operations. First, it contained more than a hint of the notion of “deterrence” that, in subsequent years, was to become a central feature of air strategy. And second, it implicitly acknowledged the radical theory that future wars might be won quickly and decisively – and, therefore, with minimum human and material loss – by air power alone.
Throughout Europe, statesmen were haunted by the spectre of fleets of bombers against which it was thought defence would be powerless. The notorious claim that the bomber would always get through came not from an airman but a politician, former British Prime Minister Stanley Baldwin, during a speech to the House of Commons in 1932. “I think it well ... for the man in the street to realise”, Baldwin informed Parliament, “that there is no power on earth that can protect him from bombing, whatever people may tell him. The bomber will always get through.”[4] Baldwin’s despairing remarks, which envisaged the inconceivable horror of men watching helplessly as their wives and children were slaughtered from the air, were widely reported.
While much of this was speculation, there was mounting evidence of the potential of air strike. In 1921, in a moment of the first magnitude in the history of combat, a formation of flimsy bombers under the command of the outspoken American prophet of air power, General “Billy” Mitchell, sank the captured German dreadnought Ostfriesland with 2,000-pound bombs during trials off Norfolk. From then on, surface ships operating without air cover had to be considered at risk.
And the predicted fearful effects of “terror” bombing seemed to assume reality during a number of highly-publicised attacks on civilians during the wars of the 1930s. The Italian Air Force flew hundreds of bombardment missions against Ethiopian towns and caravans, as well as against military targets, between October 1935 and May 1936, killing many non-combatants. Japanese air forces similarly ranged throughout China during the Sino-Japanese War from 1937 to 1939, bombing major population centres, including Beijing, Shanghai, Nanking, Hankow, and Chungking.
Perhaps the most infamous attack on civilians came during the Spanish Civil War. The terror bombing of the Basque town of Guernica by the Luftwaffe on 26 April 1937 has achieved enduring international notoriety, partly through the callousness of the attack and partly through Pablo Picasso’s epic painting of the event. Heinkel 111s and Junkers 52s attacked Guernica on market day, repeatedly bombing and strafing a defenceless crowd of about 7,000. Some 1,000 were killed and another 900 wounded. The razing of Guernica was publicised by the world press as the symbol of barbarity.
The fighting in Spain proved to be something of a testing ground because it was the first occasion since 1918 in which the main protagonists had fielded air forces of a reasonably comparable size and technical proficiency, with Franco’s Nationalists being supported by the Germans and Italians, and the Republicans by the Soviet Union.[5] Simultaneously an intense doctrinal debate was taking place within air services around the world regarding the relative weighting airmen should place on their various roles, especially control of the air and so-called “strategic” strike.
In the United States, some staff members at the Air Corps Tactical School were promoting the concept of large, fast, heavily armed, unescorted bombers flying in formation deep into enemy territory to make war-winning knock-out blows against “national organic systems”. Targets would be “carefully selected as keystone industries on which the enemy’s whole economic structure depended”.[6] But not everyone believed that bombers would be able to operate unescorted, with fighter advocates like Claire Chennault arguing that fighters would be essential both to defend vital points and to protect bombers.[7]
Across the Atlantic, the air power debate in the Royal Air Force was dominated by the immensely influential first chief of staff, Hugh Trenchard. Trenchard’s objective was, simply, to give the RAF maximum offensive power by establishing as many bomber squadrons as possible, at the expense of fighters if necessary. It was Trenchard alone who decided that the RAF’s fighters should be short-range, as they would be employed only for home defence; and that long-range fighters would not be needed to protect bombers. In his opinion the next war would be won by dropping the heaviest possible bomb load on the enemy’s homeland, to destroy the morale of its inhabitants.
Experience in Spain suggested otherwise, with commanders on both sides quickly realising that offensive operations were placed at risk if control of the air were not first established. It soon became policy to seek local air superiority for specific operations, and for bombers to have their own fighter escorts.[8] Luftwaffe commanders noted that while fast bombers were able to survive fighter attacks, slower machines, regardless of how well armed they might be, were a dubious proposition.
Coincidentally, at the same time on the other side of the world Japanese airmen were learning a similar lesson from their war against China. Japanese Naval Air Force crews on long-range strikes discovered with “devastating thoroughness” that unprotected bombers were no match for enemy fighters; conversely, they discovered that escorted bomber groups were far more likely to reach and return from their targets.[9]
Turning to other roles, in Spain the Germans also came to appreciate the value to armies of close air support, with blitzkrieg providing evidence of a lesson well-learnt two years later.[10] Soviet airmen fighting for the other side drew the same conclusion. The Spanish experience strengthened the predilection of both the Germans and the Soviets to use air forces as tactical rather than strategic weapons.
Not that the Luftwaffe lacked strategic vision. On the contrary, air power advocates such as Hans von Seeckt and Walther Wever believed that the objective of any war was to destroy the morale of the enemy, and that the bomber was the decisive weapon of air warfare. The Luftwaffe’s basic doctrinal statement was published in 1935 and clearly identified a place for independent, strategic air attacks against key enemy targets; attacks which, in the right circumstances, might decisively weaken the opposition’s will.[11] But in contrast to the strident independence asserted by many of the leading air power thinkers in Britain and the United States, the Luftwaffe placed their service’s doctrine firmly within the higher order of joint operations. Strategic bombing was unlikely to be an end in itself, but rather would be just one of a number of air power capabilities which would support the joint efforts of the army, navy, and air force, as in combination they pursued their country’s national interests.[12]
It is noteworthy that the Luftwaffe initially envisaged using medium-sized dive bombers for strategic attacks, the idea being that the high degree of accuracy possible with dive bombers would facilitate precision attacks against factories, transport, and other “special” targets.[13] This judgment stood in sharp contrast to the Allies’ preference for large, level bombers, which individually could not expect to achieve the same accuracy.
Two final observations on German air doctrine are warranted, one concerning the consequences of materiel shortages and the other the imperatives of geography. First, the Germans were handicapped by severe structural limitations, having to import almost every raw material needed for a modern war economy.[14] This placed them at an enormous disadvantage in terms of aircraft production, especially in relation to the United States. And second, German air strategists knew that from the moment war started their geography meant they faced the certainty of a land battle, a situation which did not affect their British and American rivals and which implied a great urgency to direct limited resources to the Army’s immediate needs rather than to the uncertain benefits of strategic bombing. Because of those dual pressures, the Luftwaffe’s leaders gambled initially on building a tactical air force, hoping to add a strategic heavy bomber force by the early 1940s.[15]
In the continuing struggle between fighters and bombers, technology began to assert itself. During the late-1930s, fighters with dramatically improved capabilities had started to enter service. After two decades of fabric and wire biplanes, the emergence of low-wing, all-metal monoplanes fitted with retractable landing gear, propelled by powerful, reliable engines, and armed with heavy-calibre guns, was nothing less than revolutionary. The Supermarine Spitfire Mk I of 1938 was 190 kilometres per hour faster than contemporary bombers, flew 5,000 metres higher, and was immensely more manoeuvrable. The performance gap had widened dangerously in favour of the fighter.[16]
Improvements in fighter aircraft were complemented by the development of the first effective long-distance control and reporting system, as scientists on both sides of the English Channel produced a hrevolutionary warning device known as radio detection and ranging apparatus – radar. This was a system which transformed the possibilities of defence against bombers.[17]
The development of air power was not confined to land-based platforms. Following the appearance of converted aircraft carriers during the First World War, warships which for several centuries had been the centrepiece of global military power were now exposed far more to a potential enemy’s striking forces. Admirals found themselves having to confront the distasteful question of whether or not a flimsy, relatively lightly armed aircraft could find and sink a battleship. Answers varied. In 1936, Britain’s First Sea Lord suggested that offensive air operations would be made unacceptably dangerous by intense ship-borne anti-aircraft fire, and many captains were contemptuous of the danger posed from the air.[18] Consequently, Britain entered the Second World War with inferior naval aircraft and insufficient naval pilots.[19]
At the start of the Second World War many if not most Allied army and navy officers had failed to grasp the fact that the sheer speed, elevation, and range of the air weapon had made the time and space factors that prevailed in the First World War outdated and irrelevant: that reaction times had become enormously compressed; and that battlefields had been extended. By contrast, the Germans’ innovative combination of aircraft, fast armour, infantry, and modern communications in the form of blitzkrieg demonstrated a battle-winning understanding of what was a revolution in military affairs. The Wehrmacht’s irresistible charge through Poland, the Low Countries, and France provided compelling air power lessons, as did the equally stunning advance of the Japanese Imperial Army through Southeast Asia two years later.
Exposed to the crucible of war, Allied soldiers and sailors learnt quickly. By January 1943, one of the war’s greatest leaders, General Bernard Montgomery, was instructing his senior commanders that “the air striking force is a battle-winning factor of the first importance ... you must win the air battle before you embark on the land, or sea, battle”.[20] By 1945, the Royal Australian Navy had concluded that “the master weapon of World War II [was] the aeroplane”.[21]
The war almost immediately confirmed control of the air as the prime air role, with the best-known example being the RAF’s victory in the Battle of Britain, which averted the planned invasion of the United Kingdom. That battle, incidentally, is one of the few examples of a successful defensive control of the air campaign: in general, airmen would prefer to wage an offensive campaign, that is, to destroy an enemy’s air power on the ground rather than fight a war of attrition in the skies.
Two other actions illustrated the importance of control of the air particularly well. The first was the introduction into service in December 1943 of the long range P-51 Mustang fighter, which was able to accompany USAAF strategic bombers deep into Germany. Prior to the arrival of the Mustang the unprotected USAAF daylight bomber force had been experiencing loss rates which threatened to become unsustainable.[22] The P-51, however, was able to establish local air superiority around bomber formations, thus greatly reducing their losses. As Noble Frankland concluded, the introduction of the Mustang “changed the course of the war in the air”. Technical innovation had “rescue[d] the theorists”.[23]
The second action concerns the preparations for the Normandy invasion of 6 June 1944. General Eisenhower’s deputy supreme commander, Air Chief Marshal Sir Arthur Tedder, believed the most important contribution air power could make to the invasion would be the disruption of the transport system in France. Because Fighter Command had established air superiority over France, Allied bombers were able to achieve Tedder’s aim relatively free from attack. Basil Liddell Hart later concluded that Tedder’s paralysis of the Nazis’ communications system was the single most significant factor in the success of the Normandy invasion.[24] It was the control of the air, though, that underwrote Tedder’s achievement.
The war also confirmed the growing importance of the air force contribution to surface operations. On land, the best known example was blitzkrieg. While blitzkrieg is usually associated with the German Army, the technique was used to equal effect by others, such as Air Vice-Marshal Coningham’s Desert Air Force and General Montgomery’s Eighth Army in North Africa; and, on the Russian Front, the Soviet Army in combination with the Ilyushin Il-2 Shturmovik ground attack aircraft.
At sea, Billy Mitchell’s demonstration from 1921 was quickly given operational expression by a number of actions, the most dramatic being the sinking of HMS Prince of Wales and Repulse by Japanese aircraft only three days after Pearl Harbor. The belief that aircraft had become integral to maritime operations was further strengthened by the role air forces played in the fight against the U-boats, with almost half of all German submarines lost during the war falling to direct air attack.[25]
Airlift also came of age during the Second World War, even though it rarely received the same recognition as offensive air power capabilities. The speed of mechanised warfare created a constant demand for reinforcements, resupply, and rapid mobility which only transport aircraft could satisfy.
But notwithstanding the vital contribution made to the Allied war effort by what was ultimately an enormously large, varied, and powerful range of air power capabilities, it was the strategic bombing campaigns which were the prime focus of attention. The contrasting approaches of the major protagonists to this most controversial component of air power doctrine were conspicuous. For most of the war the Allies were able to prosecute an air strategy which incorporated all of the major air power roles and missions. By contrast, Germany was constrained – by its doctrine and equipment – to a limited air strategy. The critical distinction was that the Nazis failed to establish a powerful, independent strategic bombing force comparable to that of the RAF and the USAAF.
By 1942 it was clear that the Luftwaffe’s faith in medium bombers had been misplaced, as their aircraft lacked range and bomb load and in the prevailing conditions were no more accurate than large level bombers.[26] Responding to the growing military crisis, in the middle of the war the Germans tried to reverse their policy by developing a heavy strategic bomber. They had, however, left their run too late: in particular, the Reich lagged badly behind the Allies in the design and development of aero engines, as a consequence of which their factories struggled to provide engines of sufficient power and reliability. No suitable bomber could be produced before the downward spiral of impending defeat started to tear the Nazi state apart.[27] Ultimately the V-1 and V-2 rockets constituted some kind of strategic strike force, but while they created considerable terror they were militarily ineffective because of limited numbers and inaccuracy.
During the course of the war the Luftwaffe dropped on Great Britain only three per cent of the tonnage of bombs that the Allies dropped on Germany, and was unable to mount strategic attacks of any moment against the Soviets on the Eastern Front. Many senior German soldiers subsequently attributed their defeat to the Luftwaffe’s inability to conduct a strategic air offensive similar to that of the Allies.[28]
An entirely different doctrinal approach was evident in Great Britain and the United States where, notwithstanding the pre-war controversy over air bombardment, and despite often strenuous opposition, the heirs of Trenchard and the Air Corps Tactical School were eventually able to marshal massive fleets of heavy bombers, which their political masters then directed them to use with increasingly brutal force.
The most authoritative scholar of the Anglo-American offensive, Richard Overy, has presented a powerful and grim picture of the physical and mental devastation the bombing caused. It is important to appreciate that that devastation did not really start until 1944, with over eighty per cent of the bombs dropped on Europe falling in the last 18 months of the war.[29] There is no doubt that prior to then the campaign experienced problems which on occasions reached major proportions. But after 1944 its effect was profound.
That effect was both direct and indirect. For example, as a direct result of the Allied bombing, during 1944 the Nazis production schedules for tanks, aircraft, and trucks were reduced by 35 per cent, 31 per cent and 42 per cent, respectively.[30] Additionally, an enormous amount of resources which might have been used to equip front-line troops had to be diverted to air defence. By 1944 the anti-aircraft system was absorbing twenty per cent of all ammunition produced and between half and two-thirds of all radar and signals equipment. Those figures are merely representative of the far broader impact the bomber offensive had on the German war economy.
Physical destruction and the massive diversion of resources were accompanied by psychological demoralisation. Contrary to conventional wisdom that the bombing boosted morale, the sustained campaign had a crushing effect on people’s mental state. Postwar surveys found that workers became tired, highly-strung, and listless, and were disinclined to take risks. Absenteeism because of bombing reached 25 per cent in some factories in the Ruhr for the whole of 1944, a rate which drastically reduced output and undermined production schedules. When asked to identify the single most difficult thing they had to cope with during the war, 91 per cent of German civilians nominated bombing.[31]
Almost sixty years after the event, the strategic air campaign against Germany remains surrounded by controversy. The harsh truth is, like the campaign against Japan, in the end it was brutally effective. As Albert Speer lamented, Bomber Command’s victory represented “the greatest lost battle on the German side”.[32]
Air power did not deliver the “knock-out blow” promised by its pre-war advocates; indeed, the way in which airmen went about their business too often bore an uncomfortable resemblance to the trench warfare their theorists believed would be made obsolete by the air weapon. Nevertheless, in less than six years the aeroplane had changed the face of war. Air power had radically extended the definition of “battlefield”, and had dramatically changed the meaning of such concepts as “centre of gravity”, “tempo”, and “lethality”. Ultimately, the ability to control the air and to conduct strategic bombing campaigns was decisive in the Allies’ victory.