Air power is the application of air force, more expansively defined by Billy Mitchell as ‘the ability to do something in the air’. Its history, as a means of war and as an element of strategic theory, has been defined by competing visions of what that ‘something’ should be. Mitchell's imprecision was an effort to gloss over what had, within a few years of the aircraft's invention, become a divisive issue among air enthusiasts: were aircraft new elements of modern combined-arms warfare, whose significance depended upon successful integration with other, more familiar means of fighting, or were they harbingers of a new kind of war, capable of achieving decisive strategic results by direct attack on the social, political, and psychological resources of the enemy?
No definitive answer to these questions has emerged, if for no other reason than because air power's assimilation to warfare has necessarily been shaped less by theoretical inferences than by the concrete interests, strategic predilections, and the institutional dynamics of individual states. The fact that independent air forces have become the norm among advanced societies testifies to the strength of the claim that air power has unique characteristics, which can only be mastered by those professionally committed to it. Yet the conduct of major military operations by air forces alone remains deeply suspect, and not just by those ignorant of air power's undoubted potential.
War in and from the air was imagined long before it became a realistic possibility. Fantasies of flight are as old as western civilization, and have often included elements of violence and dark premonition: the wings of Icarus melting in the sun is among the earliest and most enduring metaphors for technological hubris. Leonardo da Vinci's fanciful drawings of flying machines would contribute to his fame as a universal genius; but he kept them secret while he was alive, because he feared they would appeal to the evil in mankind. Eighteenth-century Frenchmen who witnessed the Montgolfier brothers' early experiments with hot-air balloons had no difficulty picturing soldiers dropping out of the sky; while Tennyson, a half-century later, imagined ‘a ghastly dew’ descending from ‘the nations' airy navies, grappling in the central blue’ (Locksley Hall, 1842). By the turn of the 20th century, the English novelist H. G. Wells was able to present a fully fleshed-out vision of strategic bombardment directed against cities, in which the bridges and public buildings of New York were suddenly destroyed by airships launched from Germany, half a world away (War in the Air, 1908). It is no exaggeration to say, in cultural terms, that when air power became a reality it was almost literally a dream come true.
Almost indeed, for as a practical matter air power has frequently fallen short of the hopes it has inspired. At the time Wells wrote, there were perhaps 100 military aircraft in the world, plus a larger number of lighter-than-air craft. The prospective military value of such ‘airships’ had been increased by the development, in the 1880s, of steering mechanisms (hence the French-derived word dirigible), which might allow such vessels to be used for tactical observation, and even as weapons. The Hague Conference of 1899 was persuaded by the Russian delegate to ban airships as platforms for guns or explosives, although the American representative successfully argued that the ban should last only five years on the grounds that military aircraft, once perfected, would prove a boon to mankind, by making war shorter and less destructive.
The hope that this promise should somehow be fulfilled was only heightened by WW I, in which air power played a considerable, but not a pre-eminent, part. Throughout the war, the most important air mission was scouting. In this role aircraft were aided by two other new technologies: photographic film (developed by the Kodak company as a replacement for coated glass plates) and wireless telegraphy. Film exposed by aerial photographers could be dropped directly to relevant headquarters, developed, interpreted, and put to immediate operational use; while aircraft (including balloons) equipped with wireless sets were regularly employed as observers for artillery. In practice, the problems of understanding and applying such intelligence proved formidable, and the confidence of commanders on the ground that they possessed what a later age would call ‘information dominance’ over their opponents was often misplaced. Nevertheless, by the end of the war it was essential to conceal one's forces as far as possible from the airborne eyes of the enemy and another French-derived word, camouflage, had long since become known to all combatants.
The value of aerial reconnaissance was certainly sufficient to make it worth denying to the other side. It was the need to shoot down the enemy's scouts and spotters while protecting one's own that gave rise to air-to-air combat, initially by pilots and back-seat observers using ordinary firearms or machine guns mounted on the fuselage, then by aeroplanes that had themselves become weapons. The main obstacle to the creation of an effective fighter plane was the propeller, which made it difficult to mount a centre-line gun the pilot could aim himself. The solution, a synchronizing gear that allowed the engine to control the gun, was devised at the end of 1915 by Anton Fokker, a Dutch engineer working in Germany. In early 1916 his redesigned machines acquired a fearsome reputation, and gave the Germans, for a time, true air superiority over the western front—which was lost almost immediately after one of the new planes accidentally landed at a French airfield, giving the secret away. Although the Germans were usually a step ahead of their opponents technologically at most stages of the war, superiority in the air ultimately rested with the western Allies for the same reasons that applied on the ground: they possessed significantly greater economic and industrial resources, which allowed them to out-build their opponents.
The men who flew the fighters became popular figures of mythic proportions, partly because of the sheer, romantic improbability of flight, but also because they seemed to have restored an element of single combat to the anonymous slaughter of modern war. Victory in the air was thought to be a matter of personal skill, heroism, and the luck of the brave—an image that survived long after air tactics had begun to acquire the characteristics of deadly routine. The lone ace was largely a figure of the war's first two years. Thereafter, air combat was increasingly dominated by squadrons or ‘wings’ comprising dozens of planes, which flew in prescribed formations, and engaged in mass combats that were normally decided by speed, numbers, and an opportunistic approach from behind. At the end of the war, some of the most talented German pilots were opting to fly observation planes, which allowed some scope for individual initiative. As America's most famous aviator, Eddie Rickenbacker, would later admit, fighting in the air had quickly lost the qualities of a ‘sport’, and had become instead ‘scientific murder’ (Fighting the Flying Circus, 1919).
Over the course of the war, the major belligerents in Europe produced tens of thousands of military aircraft of all types, only a tiny fraction of which were committed to offensive operations. Airmen, needless to say, showed themselves eager, hurling grenades and firing their weapons at targets on the ground from the earliest days of the war. In time, their ability to strafe troops and destroy selected transportation, command, and storage facilities would inspire a justified measure of fear among those below (including, it must be admitted, those on their own side). Technically the problems of delivering genuinely significant fire from the air took time to solve. The vessels that H. G. Wells had imagined devastating New York had been Zeppelins—immense, rigid, motorized airships named after their German inventor—and such craft were the only ones capable of lifting more than a few hundred pounds when the war began. Their vulnerability to artillery fire and fixed-wing aircraft soon became apparent, and their value against defended targets was severely limited.
True bombers emerge during the middle years of the war, in the form of large, multi-engine monoplanes capable of lifting up to a ton of explosives—German Gothas and Handley-Page 0/100s and 0/400s. London and Paris were both attacked repeatedly from the air during the war, and sustained several thousand civilian casualties. Berlin was too remote to suffer retribution, though one intrepid French pilot did manage to drop a load of leaflets there, and German cities in the Ruhr and Rhineland were struck by British and French aviators. In October 1917 Britain created an independent air wing (41 Wing) for strategic bombing, the precursor of the RAF, which was created on 1 April 1918—the world's first independent air force. Had the war lasted longer it is certain that the scale of such efforts would have increased, despite reservations on all sides about the moral and political consequences of attacks upon civilians. Although the absence of effective bomb sights (and in some cases effective navigation) made strategic air attacks decidedly indiscriminate, this did not lessen their psychological impact, which exceeded the physical destruction involved. A week of Zeppelin and bomber raids directed against London in September 1917 caused 300, 000 people to seek shelter in underground rail stations (not for the last time) ; and by the end of the war an equal number were manning the vast network of anti-aircraft artillery and so-called barrage balloons with which the world's largest city, and now its greatest target, sought to defend itself.
Air-power theory, strictly understood, arose by way of reflection upon these experiences. Among the most incisive (if little read at the time) early interpreters was the Italian Douhet, whose Command of the Air (1921) first set down a number of basic propositions that, however contestable, have proven central to all subsequent discussions of its subject. He believed that, if nothing else, recent events had demonstrated the futility of offensive ground operations under modern conditions. In the air, in contrast, everything seemed to favour offensive action, a conclusion that was justified less by the actual accomplishments of aeroplanes so far than by the apparent difficulty of shooting them down. Aeroplanes had also made conventional distinctions between combatants and non-combatants irrelevant. While some might conceive scruples about deliberate attacks upon civilians (a war crime under the same Hague Convention (see Geneva and Hague Conventions) that tried to outlaw war in the air), it was certain that others would not, and they would impose an inexorable strategic logic upon all alike. Wars in the future would begin with massive air offensives, directed not against the enemy's armed forces (whose role had been reduced to that of holding a defensive line) but against his cities. Such attacks would achieve their effects by psychological shock so profound as to leave the government no alternative but surrender—perhaps within hours. Logically, the only defence against such a disabling blow would be the ability to deliver one in reply, for which a standing air force in a state of perpetual alert would be indispensable.
Less baleful interpretations were possible. Many who favoured strategic bombing doubted that its impact on public morale would suffice to end a war. It was not obvious exactly how such psychological effects as Douhet imagined, even should they occur, would make themselves felt upon a government, nor whether a government thus delegitimized would still be capable of coming to terms. The air war envisioned by Wells had not been short and decisive. While strategic bombing as he had imagined it was sufficient to destroy public order, the result was not peace, but ‘universal guerrilla war’. Air enthusiasts in maritime countries especially— Trenchard in Britain and Mitchell in the USA—were less inclined to conceive of air power as a stand-in for Armageddon—though Mitchell's prophetic description of Japan's ‘paper cities’ in flames stand out, even by the apocalyptic standards of the time. Air power might best be understood as a form of economic warfare, which worked like a particularly brutal naval blockade, by destroying the enemy's war industries and productive capacity over time. In this context, victory through air power required only conventional strategic rationality on the part of an opponent: the losing side would be the one that first judged the price of continued bombardment to outweigh whatever prospects of success remained. For Mitchell and Trenchard, what mattered in any case was not the precise theory that governed the conduct of air war, but the establishment of independent air forces that would be free to explore their unique environment, without being held hostage to the obsolete conceptions of those condemned to fight on the ground.
Those thus condemned were nevertheless prepared to press their own claims. In continental countries with strong traditions of land warfare, air power was seen less as an alternative to tactical stalemate than as a solution to it. Although no major power was prepared to dismiss strategic bombing out of hand, those like Germany that were least equipped to sustain a protracted war of attrition were more inclined to view aeroplanes as akin to flying artillery. The Ludendorff offensive of March 1918 had employed squadrons of aircraft in direct support of infantry, and it was not entirely fanciful to wonder whether such a potent combination of fire and movement, had it been available in quantity a few years earlier, might not have changed the outcome of the war. Aircraft in this role, it was considered, might confound those higher in the sky, by assisting in the achievement of a decisive breakthrough on the ground, before the effects of strategic air bombardment could begin to bite. In these terms, ‘command of the air’ did not make effective ground operations unnecessary; it simply made them possible.
A narrower range of choices confronted those who fought on the sea. Sailors were no less ready than soldiers to employ aircraft to solve traditional problems—above all fleet reconnaissance, for which specialized planes and tenders were already in action in 1914. But few imagined that aircraft launched from ships could transform naval operations. Most regarded naval power and air power as rival conceptions: both were promoted, by their most committed advocates, as means of rendering the clash of land armies ancillary to strategic success. The spectacle of the German dreadnought Ostfriesland being sunk from the air—arranged by Billy Mitchell in July 1921 as a demonstration of the aircraft's value for coastal defence—was superficially unnerving, but in the end unconvincing: the ship had been undefended and tethered when it was sunk. It was only the advent of effective radar and radio in the late 1930s that made aircraft carriers effective all-weather warships.
Thereafter the prospect that battleships might lose their pre-eminence was foreseeable—though it was only the actual experience of war that made it clear to everyone. The nature of the change should not be overestimated: aircraft carriers revolutionized naval tactics, but not naval strategy. Carriers replaced battleships only because aircraft could perform the functions of naval guns more effectively. They also proved helpful in controlling another, even more profound menace to the future of surface navies: submarines. In the absence of escort carriers and long-range land-based observation aircraft, the battle of the Atlantic might easily have lasted another year—though the outcome would almost certainly have been the same. Still, the simple fact that the idea of the ‘capital ship’ survived the aircraft's ascendancy illustrates how little had changed. Navies now fought each other at vastly greater ranges, but for a familiar purpose: to command the sea, while denying its use to the adversary. Air power proved an essential means to this end, but not more than that.
The aircraft's most profound impact on naval operations in WW II involved the interaction between maritime forces and the land. The threat of attack by land-based aircraft exerted a continuous influence on all surface navies, most decisively so in the Mediterranean, while the need to establish forward-deployed island airbases controlled the basic rhythm of the island-hopping offensive in the Pacific. Conversely, the strategic bombardment of Japan, conducted by land-based aircraft launched from islands seized and sustained by naval forces, was less a vindication of air power per se than a demonstration of the lethality of naval power, ruthlessly applied. The atomic bombs that devastated Hiroshima and Nagasaki were immediately hailed by air enthusiasts as the technical embodiment of the old Douhet prophetic vision. They were in reality projectiles ultimately fired by the US navy.
The war in Europe presented a similarly variegated picture of air power in action. It demonstrated the centrality of ‘doing something in the air’ to all aspects of modern combat; but in ways that were difficult to analyse independently. The promise that aircraft would restore the power of manoeuvre to armies on the ground was fulfilled from the start, as German forces supported by a purpose-built fleet of ground-attack aircraft swept across Europe. Yet the war did not end as a result, and as it dragged on air power emerged less as an alternative to attrition than as one of its many instruments. Those who might still have imagined that the air was a realm of personal daring and bold expedients were destined for disappointment. Command of the air in WW II was an industrial process, in which numbers and sheer weight of metal ultimately proved decisive.
This is not to suggest that success was in any sense automatic once the necessary investment had been made. On the contrary, the expectations that attached to air power before the war had depended on a false assumption: that, as Stanley Baldwin told the House of Commons, ‘the bomber will always get through’. In fact, rapid advances in the speed, range, and firepower of fighter aircraft, combined with the development of ground-based radar capable of guiding them to their targets, made aerial bombing a decidedly haphazard and risky enterprise. Even planes that managed to avoid being shot down could be driven off their aim by a vigorous defence, with the result that only about half the bombs dropped in the early years of the war fell within 5 miles (8 km) of their targets. Casualties among air crews were also alarming. When the war ended, losses in the RAF exceeded those of the Royal Navy, a possibility that few would have credited at the outset.
These problems had broader implications. If the goal of strategic bombardment was to erode ‘the enemy's will’—which is to say, civilian morale—the accuracy of individual air strikes made little difference. The natural targets were cities—the only thing large enough to be struck with real confidence in any case; and they could be hit more safely and no less well at night. This was a conclusion to which both the Luftwaffe and the RAF were drawn as a consequence of severe early losses. The USAAF, in contrast, remained committed to what it liked to call ‘precision’ daylight bombing—though it may be noted that only the lead aircraft actually tried to aim its bombs, while the rest simply dropped theirs as close to simultaneously as possible. In time, a kind of archetypal target list emerged, whose underlying logic continues to influence the conduct of air campaigns to this day. At the top were air defence assets—it had quickly been concluded that the Luftwaffe's failure to concentrate on the RAF's airfields and radar stations had hurt its chances during the battle of Britain. Next came transportation targets, especially rail junctions and fuel storage facilities, upon which the movement of large ground forces depended. Bombing of this kind played a critical role in preparing for the Normandy invasion, and appears in retrospect to bridge the conceptual gap between direct support of forces in contact with the enemy, and the more remote effects of strategic bombing as originally conceived. Daylight raids were also carried out against factories producing war matériel, against hardened military targets like submarine pens, and against targets of special political importance, like the launching sites for the V-weapons in 1944—an unnerving premonition of what air power would soon become.
The relative risks and rewards of ‘area’ versus ‘precision’ bombing were contested throughout the war, without yielding any firm conclusions about their relative merits. Efforts to draw a moral distinction, at any rate, are misplaced: all forms of strategic bombing in WW II entailed deliberate attacks upon civilians. Certainly the losses incurred in daylight raids could be daunting. In its famous attack on the Schweinfurt ball-bearing works in June 1943, the US Eighth Air Force lost 147 out of 376 planes, to little purpose other than to induce the enemy to move some of his factories to more remote locations. The odds were improved the following year with the appearance of a long-range fighter, the P-51 ‘Mustang’, that could escort attacking planes all the way to their target. By then, the lifting capacity of the average front-line bomber had also improved five- or even tenfold from what it had been early in the war. Most of the bombs that fell on Germany, by day or night, did so during the last year; which was also the year in which German aircraft production—overwhelmingly fighters—reached its peak. Whether this testified to the ultimate futility of the strategic air campaign, or to the disproportionate fear it inspired, would be hotly disputed once the smoke had cleared.
Such quibbling aside WW II effectively decided the question whether ‘air power’ was real or not. It remained to discover what kinds of institutional arrangements were best suited to make use of it. At first glance there was much in recent experience that argued against a firm distinction between air warfare and other kinds. The fact that people could no longer conceive of any major military operation that did not involve an air component seemed to many sufficient to justify the decentralized integration of air forces within armies and navies. Against this temporizing view stood the previously unimaginable devastation of the strategic air campaigns, whose stunning climax in the skies over Japan seemed to have drawn a line under the military experiences of the past. The world had finally been made new, and air power had done it. When the USA, the only country to possess nuclear weapons, decided in 1947 to place them in the hands of an independent air force (along with most military aircraft), a half-century of speculation about what air power would look like in its maturity seemed to have been settled.
Although nuclear weapons became the ultimate expression of aerial bombardment as an independent strategic force, it was the advent of intercontinental bombers and ballistic missiles that truly freed air power from its residual dependence upon the enabling actions of other services. They did so, however, at the cost of ensnaring it in the atavistic logic of the wonderfully apposite acronym MAD (mutually assured destruction), whose only rational purpose was to ensure that such weapons would never actually be used. By the middle of the 1950s, few doubted that air power could bring an end to civilization—which, in a sense, placed it in a category so special that it barely qualified as warfare at all.
Air advocates, even those most deeply committed to nuclear deterrence as the air mission of the future, were not disposed to accept relegation to the remotest corner of the strategic universe. On the contrary, it seemed obvious that the warrant to wreak unlimited havoc from the air implied a claim upon less cataclysmic military missions as well. Curtis LeMay, COS of the USAF, did not hesitate to present strategic air power as the universal solvent of modern war, based upon doctrinal principles that, as he testified before Congress in 1961, had not changed since the formation of America's first Air General Headquarters in 1935. A few years later, when the call came to devise a bombing plan that would compel North Vietnam to cease undermining the independence of the South, it was a simple matter to devise a list of military, logistical, and industrial targets whose systematic destruction would rapidly bring the enemy to terms.
The strategic air campaign conducted by the USA in Indochina between 1964 and 1972 was the largest such effort in history and testified, if nothing else, to the exaggerated confidence that air power now inspired. Over half of all the money spent on the war by the USA was expended to conduct air operations, only about 20 per cent of which were linked to operations on the ground. The remainder were strategic strikes as traditionally defined, intended to coerce the enemy by degrading his military and economic infrastructure, demoralizing the population, and persuading the political leadership that it had more to gain by settling than by continued resistance. These efforts failed. Post-war analysis revealed that the material cost of conducting the air war far exceeded the value of the things it destroyed (human life excepted), without ever coming close to breaking the North's will to continue, or to denying it the physical means of supporting its forces in the South.
Airmen were quick to blame political considerations that limited their choice of targets, and prevented their attacks from developing sufficient intensity early in the war, before the enemy could take steps to disperse his population and build up his air defences. Critics responded that restrictions intended to avoid provoking Soviet or Chinese intervention were scarcely unreasonable in military terms; and that the political leadership of a democratic country, engaged in a war that did not threaten its existence, could not be indifferent to the stigma of having inflicted massive civilian casualties. Strategic air power, moreover, was by definition supposed to achieve not merely military, but political, results. Its purpose was to coerce political choices, and it was entirely logical that operational control should be shared by political experts.
Vietnam exposed the limits of air power theory as it emerged from WW II, without entirely discrediting it. Operationally, the much-admired capacity of air forces to attack logistical and economic targets became subject to more severe discounting. Demolishing the industrial infrastructure of a pre-industrial society accomplished less than had been imagined; while the logistical base of a revolutionary insurgency proved too attenuated to be struck by so blunt an instrument as an aerial bomb. Strategically, the vaguely speculative social psychology embedded within phrases like ‘breaking the enemy's will’ came in for closer scrutiny. In a totalitarian state like North Vietnam, where political decision-making was sustained by ideological passion, and insulated from public opinion, it was hard to know what level of suffering might be necessary to convince the government to call it quits—a consideration that had been obviated in WW II by the intention to compel unconditional surrender in any case. In Vietnam, by contrast, strategic bombardment was employed as a form of negotiation, and was regularly halted and restructured to support more conventional diplomatic efforts. Such a practice, although strictly reasonable in theoretical terms, proved profoundly demoralizing. Having escaped from the labyrinth of deterrence theory, American airmen found themselves trapped in a semiotic hall of mirrors.
From which, it may be added, they have not yet escaped. Despite the disillusionment of Vietnam, air power has remained the instrument of choice for the conduct of limited war by advanced democracies, if for no other reason than because it holds out some prospect of achieving useful military results with minimal own casualties. Whether the pulverizing Gulf war air campaign conducted by the USA and its allies against Iraq, following its invasion of Kuwait in 1990, would have counted as ‘strategic’ bombardment in the eyes of Curtis LeMay is difficult to say. Air operations in the Gulf were designedly part of an integrated, joint military campaign, rather than a free-standing enterprise. Yet normal tactical considerations dictated a protracted period of aerial bombardment at the start; and while it was underway it proved impossible, even for those most knowledgeable of military realities, to suppress the hope that the bitter cup of ground combat might somehow pass from them.
In such circumstances, the commitment of ground forces ceases to be a normal military act, implicit in the original decision to go to war, and becomes a discrete political moment with its own logic and consequences. This pattern has been strengthened by the development of stealth aircraft and precision-guided munitions, including highly accurate, pilotless cruise missiles, which have further reduced the risk of casualties to the side that employs them (and often to the other side as well). Such weapons have proven remarkably easy to use, to the point where they have become an almost predictable expedient of crisis diplomacy. Yet there is no evidence to suggest that the remarkable precision of modern aerial weapons extends to their political effects. On the contrary, weapons that are easy and painless to use are poor instruments for communicating resolve—though they may be effective in inspiring it in those on the receiving end. Although one should not be too quick to underestimate the coercive power of such methods, they remain subject to all the friction, uncertainty, and escalatory pressure that afflict war in any environment—a proposition that no serious student of air power would wish to dispute.
Bibliography
- Boog, Horst (ed.), The Conduct of the Air War in WW II: An International Comparison (New York, 1992).
- Clodfelter, Mark, The Limits of Air Power: The American Bombing of North Vietnam (New York, 1989).
- Higham, Robert, Air Power: A Concise History (New York, 1972).
- Kennett, Lee, The First Air War, 1914-1918 (New York, 1991).
- Mitchell, William, Winged Defense: The Development and Possibilities of Modern Air Power (New York, 1925).
- Pape, Robert A., Bombing to Win: Air Power and Coercion in War (Ithaca, NY, 1996).
- Sherry, Michael S., The Rise of American Air Power: The Creation of Armageddon (New Haven, 1987)
— Daniel Moran
