Forrest E. Morgan
It should come as no surprise that the concept of airpower has changed a great deal since H.G. Wells first used the term in his 1908 science fiction novel, The War in the Air. Given the passage of more than a century, the world has seen dramatic advances in technology as well as changes in the geopolitical condi-tions in which war is fought. Yet within the ever-evolving fabric of airpower his-tory, one can find remarkable threads of continuity. Early aircraft, though but fragile contraptions of wood and canvas, exploited the same advantages enjoyed by the sophisticated weapons systems that operate in today’s 21st-century skies:
the ability to cover great distances in any direction quickly, free of obstruction by surface terrain; the ability to overfly enemy armies and navies and attack them from above, across the breadth and depth of the battlespace; and the ability to take war to the heart of an enemy’s society, striking vulnerable targets previously unreachable before defeating surface defenses. So there should be little wonder that the concept of airpower, while ever evolving, has also exhibited elements of continuity, as have the doctrines and strategies that conceptual thinking about airpower has inspired. In many ways and for reasons that are clearly evident, today’s airmen have inherited the strategic mindset of their forebears.
This paper examines that mindset in historical context as it traces the evolution of airpower thought and considers what theoretical, technological, and political trends suggest for strategies that air forces will likely employ in the future. It explains how airpower thought, though buffeted by changes in technology and geopolitics, has been anchored on an evolving body of the-ory conceived to exploit the unique warfighting advantages afforded by the ability of aircraft to operate in the vertical dimension. Yet within this unifying framework, strategic thinkers have, from the earliest days of military air opera-tions, debated whether airpower is employed most effectively as an indepen-dent instrument against targets chosen to create direct, war-winning effects at the strategic level of war, or whether it is better used in combination with sur-face forces at the operational level of war. I argue that these competing ideas appear to be converging in the current era, but the debate is unlikely to ever be fully resolved. That is a good thing because strategy has always benefited
from rigorous examination and spirited intellectual debate. Creative thought and innovation have always been the touchstones of airpower. That heritage will continue into the future.
The Dawn of Airpower Thought
When military authorities hesitantly began acquiring “aeroplanes” in the years immediately following Orville and Wilbur Wright’s first flight of a heavier-than-air craft, the missions they had in mind for these new machines flowed from the novel but limited capabilities they offered. Considering them too fragile for combat and unable to carry ordnance heavy enough to contribute anything meaningful to artillery bombardment, the U.S. Army, along with the armies of several European countries, nevertheless saw potential applications in commu-nications and reconnaissance in the airplane’s speed and the visual perspective afforded by altitude. Such were the missions in which aircraft were first employed in combat, over Libya in 1911, the Balkans the next year, and, more significantly still, in Europe when war broke out in 1914. But it did not take long for the airmen flying these machines to begin finding combat applications for the unique capa-bilities that the new technology provided. Almost immediately, enemy reconnais-sance aircrews began harassing each other, first throwing bricks and hand gre-nades, later shooting at each other with handguns, rifles, and ultimately mounted machineguns. Before long, air services on both sides organized “pursuit” squad-rons with aircraft and crews dedicated to the air-to-air combat mission. By mid 1916, both the Germans and the Franco-British allies had developed machine-gun synchronizers, allowing them to fire ahead along the axis of flight by shoot-ing between the propellers, thus creatshoot-ing the first true fighter planes.1
Meanwhile, aviators developed techniques to strafe and bomb enemy trenches, and they began attacking lines of communication in efforts to inter-dict the movement of men and materiel to the front. The Germans even pio-neered the use of strategic bombing, striking London and other urban targets from lighter-than-air dirigibles, beginning in 1915. Later, in 1917, when the unwieldy Zeppelins began taking too many losses, German leaders transferred the mission to faster, more maneuverable Gotha and Giant bomber aircraft.
Indeed, by the time U.S. aviators officially entered the war that same year—
American volunteers had participated unofficially in the French Air Service’s Lafayette Escadrille (originally Escadrille Américaine) since April 1916—all of the principal missions flown by today’s air forces had already emerged in some form. Nevertheless, air operations ultimately had a negligible effect on the course of the war, due to the limitations in payload weight and bombing accu-racy that constrained aircraft capabilities in that era.2
Despite these limitations, several visionaries saw beyond the constraints of contemporary technology to grasp the potential of how aircraft might affect the outcomes of future wars, triggering the emergence of formal airpower the-ory. One of these individuals was Giulio Douhet, an artillery officer in the Ital-ian army. Douhet had watched the rapid development of combat aviation dur-ing the war and saw in the emergdur-ing capability of bomber aircraft a potential for striking enemy countries where he thought they were most vulnerable, their cities. In his 1921 book, Command of the Air, and several subsequent publica-tions, he theorized that airpower could be used to end wars quickly by bomb-ing urban areas to break the enemy’s material and moral resistance.3 Countries with the foresight to embrace the potential of airpower could thereby avoid repeating the bloody stalemate of the last war, where more than 8 million men had given their lives, many in frontal assaults against machineguns, artillery, and barbed wire, while stalled at the trenches in France.
Aircraft had the advantageous ability to strike the heart of an enemy’s country without having to defeat its armies first. Though World War I had demonstrated that disciplined soldiers could withstand considerable bom-bardment without breaking, Douhet believed that civilians would not be so resilient. Bombers could overfly enemy armies, thus avoiding the adversary’s hardened crust, and bomb major cities, causing panic and generating popular pressure to end the war. Douhet argued, however, that Italy could not afford to build the bomber force needed to carry out such a plan if it continued squan-dering its scarce defense resources on less effective military capabilities, such as ground and naval forces. Nor could the air service achieve its full potential if it continued to be administered by the army, because army generals would insist that aircraft be used to attack enemy forces and perform other battlefield mis-sions in support of ground operations.
Douhet proposed that Italy, instead, build an independent air force com-prised primarily of heavily armed “battle planes.” In the event of war, these planes would not waste time attacking the enemy army. Rather, they would first dispose of the greatest threat that a savvy adversary could muster—the enemy air force. Douhet’s first objective would be to bomb the adversary’s air-fields, destroying enemy planes on the ground and any that rose to challenge his battle planes, until Italy achieved command of the air. Then the air force would turn its attention to the enemy’s capital and major cities, bombing the civilian population into submission and enemy leaders into surrender.4
Another airpower visionary during the interwar years was Britain’s Air Marshal Sir Hugh Trenchard. Having commanded the Royal Flying Corps dur-ing World War I, he was an ardent believer in the war-winndur-ing potential of air-power and the chief interwar champion and architect of Britain’s independent
Royal Air Force (RAF). According to historian Phillip Meilinger, “Trenchard carried three main beliefs with him from the war: air superiority was an essential prerequisite to military success; airpower was an inherently offensive weapon; and although its material effects were great, airpower’s psychological effects were far greater.”5
In the years leading to World War II, under Trenchard’s guidance, the RAF developed a doctrine for strategic bombing which maintained that victory in war resulted from the collapse of civilian morale. Like Douhet, Trenchard disparaged dissipating airpower’s unique capabilities in attacks on armies in the field. Rather, the RAF’s principal doctrine publication, AP 1300, Royal Air Force War Manual, advocated bombing industrial centers to drive workers from the factories and destroy economic infrastructure—including public utilities, food and fuel supplies, transportation networks, and communications—to cause “a general undermining of the whole populace, even to the extent of destroying the nation’s will to continue the struggle.”6 And like Douhet, Trenchard insisted that the RAF retain its institutional separation from the army in order to hus-band the resources and maintain the freedom of action needed to carry out its independent mission.7
While U.S. aviators were influenced by Douhet and Trenchard, they were most inspired by the very public and often caustic arguments proffered by their own airpower champion, Brigadier General William “Billy” Mitchell.
As a senior U.S. air officer in France during World War I, Mitchell was well acquainted with Trenchard, and after the war he also consulted with Douhet and Italian bomber designer and manufacturer Gianni Caproni.8 Like his European counterparts, Mitchell was an ardent believer in airpower as an independent, war-winning weapon, and he argued vociferously that the air services should be granted separation from all Army and Navy control. In Mitchell’s view, air warfare was unique, and only airmen, whom he saw as a
“distinctive class of … aerial knights engaged in chivalrous combat,” had the proper mindset to lead it.9 It was a romantic image, one that he painted for public consumption at every opportunity in books, speeches, magazine arti-cles, and newspaper editorials, often criticizing Navy leaders and even his own superiors in the Army for their hidebound attitudes and for mismanag-ing the air assets under their control. Ultimately, his public defiance of mili-tary authority resulted in his court martial and resignation from the Army, but he continued to extol the virtues of independent airpower in publications and speeches until his death in 1936.10
Officers on the faculty of the U.S. Army’s Air Corps Tactical School (ACTS) at Maxwell Field, Alabama, followed the international airpower debate with interest.11 They too believed aerial bombardment was a weapon
with war-winning potential, one best employed as an independent instrument against a country’s vulnerable interior, but they were less than sanguine about Douhet’s and Trenchard’s conviction that the key to victory lay in directly targeting the enemy’s moral resistance.12 Rather, having observed that warfare between industrial states had become very resource consumptive, they theo-rized that bombing an enemy’s armaments industry could deny him the capa-bility to wage war as well as the will to do so. Relying on deductive reasoning and circumstantial evidence—such as when a temporary closing at the only plant in the United States that manufactured a spring essential to the assembly of variable-pitch propellers brought aircraft production to a nationwide halt—
ACTS theorists surmised that every industrialized nation-state had become a network of interconnected economic systems, an “industrial web,” with critical points, the destruction of which would lead to its collapse.13
Of course, striking such critical points from the air with sufficient force and accuracy to destroy them would be challenging—it could only be done with mass raids in daylight. And the enemy would resist mass bomber raids with all the fighters and antiaircraft artillery it could muster—the bombers would have to fly high and be fast and heavily armed. But comparing the capabilities of fight-ers and bombfight-ers of that era, and examining the development of such new tech-nologies as the Norden bombsight, they concluded that “high-altitude, daylight precision bombing” was not only possible, it would be key to winning a war with an industrialized state. Therefore, “an inviolable principle of ACTS was that air-men use the bomber only against vital material targets located deep within hos-tile territory and that it never serve in harassing operations of the Army.”14
Although theories for employing airpower as an independent, war-win-ning weapon were in vogue in several of the world’s leading air services, they were by no means universally accepted, and so an opposing line of thought—
airpower at the operational level of war—arose. In Germany, for instance, desires to develop and employ strategic bombing were tempered by the need to use airpower in support of ground operations. As Germany was a continen-tal power with contiguous borders with its traditional enemies, Luftwaffe plan-ners recognized that they would likely be called upon to support the army at the onset of any future war. Nevertheless, Germany had its own interwar strategic bombing theorist in the person of Dr. Robert Knauss, a World War I combat veteran who afterwards helped shape Lufthansa, and whose ideas largely mir-rored those of Douhet.15
The Chief of the Luftwaffe General Staff, Walther Wever, who advocated a balanced development of airpower capabilities, also believed strategic bomb-ing would be an important arrow in Germany’s quiver. In 1934 he ordered work to begin on a long-range “Ural Bomber” that would enable the Luftwaffe
to bomb military and industrial targets deep in the Soviet Union.16 However, several factors constrained the Luftwaffe’s development of capabilities for con-ducting strategic air warfare. First, the General Staff worried that the “ter-ror bombing” that Douhet and Knauss advocated would provoke Germany’s enemies to reciprocate with revenge attacks on German cities, so they blocked all attempts to have such tactics written into Luftwaffe doctrine.17 Second, although there was considerable interest in the early 1930s in developing long-range bombers for use against industrial targets, the Germans failed to clear the technological hurdles that would have allowed them to develop aircraft engines powerful enough to carry heavy payloads at the altitudes and distances needed to accomplish that mission. Finally, and perhaps most importantly, the Luftwaffe’s most influential strategic bombing advocate, Walther Wever, met an untimely death in an air accident in 1936. With his demise, the Ural Bomber project was canceled and Reich Air Minister Hermann Goring put the Luft-waffe in the hands of generals more interested in developing capabilities for supporting ground operations.
Consequently, from that point onward German airpower development focused on capabilities for supporting actions at the operational level of war.
The Luftwaffe began procuring fighters and fast medium bombers for destroy-ing enemy airpower in the battle zone rather than by bombdestroy-ing aircraft pro-duction. General Ernst Udet, whom Goring appointed to direct the Office of Technical Development in 1936, insisted that all future bombers be designed as dive-bombers.18 General Hans Jeschonnek, appointed chief of the Luft-waffe General Staff in 1939, was similarly enamored with dive-bombing. As a result, dive-bombing was emphasized over level bombing and aircraft such as the Junkers Ju–87 Stuka (for Sturzkampfflugzeug: “dive bomber”) became exemplars of German airpower thought. Ultimately, the Luftwaffe’s doctrinal thrust shifted to providing interdiction bombing and close-air support (CAS) for armor and infantry actions in Germany’s emerging high-speed maneuver warfare doctrine, which, soon after its first employment in Poland, was dubbed Blitzkrieg (Lightning War).19
Similar, though not identical, experiences can be seen in other coun-tries during the interwar period. The Soviet Union had its own strategic bombing advocate in the personage of Air Force General A.N. Lapchinsky, who in the early 1920s wrote a book and several articles arguing that strategic bombing would be a major weapon in future wars. Alternatively, Army Chief of Staff Marshal Mikhail Tukhachevskii, while acknowledging a future role for strategic bombardment, maintained that airpower should be used mostly in joint operations, with light bombers, fighters, and ground-attack aviation integrated with armor and artillery employment in the execution of “deep
battle” doctrine.20 Early on, Lapchinsky’s ideas found favor among Soviet avi-ators, ironically, not so much from a rational analysis of airpower capabilities as from a belief that strategic bombing was a “modern” form of warfare and therefore more appropriate for a military system built on Marxist-Leninist principles.21
However, as Soviet airpower thought matured, the orientation shifted.
During Germany’s 1925–1933 air mission to the Soviet Union, German instructors emphasized the importance of air-ground cooperation at the oper-ational level of war. Later, during the Spanish Civil War (1936–1939), in which Germany and Italy deployed forces in support of the Nationalist cause and the Soviet Union supported the Republican side, air forces on both sides briefly resorted to population bombing, but ultimately enjoyed much greater success when they used their airpower in support of ground operations. By the end of the 1930s, the Soviets, like the Germans, concluded that, given limitations imposed by the technology at their disposal, airpower concepts developed around short-range ground-attack aircraft would suit their needs better than those requiring aircraft that they lacked the capability to produce.22
Japan and even Italy, the home of Giulio Douhet, exhibited similar pat-terns in thinking. Japan attempted to develop long-range bombers and the Jap-anese army and navy air services resorted to population bombing in Shanghai, Guangzhou, Nanjing, and Chongqing starting in 1937 in the war against China.
But the Japanese experienced the same technological limitations and disap-pointing outcomes as did the continental powers of Europe, and they subse-quently focused their greatest efforts on using airpower in support of surface forces. Italy, alternatively, never made a serious effort to develop strategic bomb-ers. Although Italian air force leaders paid lip-service to Douhet—likely prudent, as he was a prominent Fascist—in practice they dismissed his ideas as immoral and inappropriate for Italy’s geostrategic challenges, following instead the more operationally-focused ideas of Amedeo Mecozzi. As the Spanish Civil War con-firmed their thinking, the Italians increasingly focused their attention on devel-oping doctrine for using airpower in support of ground and naval operations.23 Applying Airpower Thought to Shape Air Strategy in World War II
The beginning of World War II saw German airpower applied at the operational level of war with stunning results. On September 1, 1939, Germany unleashed Blitzkrieg on Poland. The Luftwaffe began the operation with massive air attacks on airfields and other military targets across the country. Although
The beginning of World War II saw German airpower applied at the operational level of war with stunning results. On September 1, 1939, Germany unleashed Blitzkrieg on Poland. The Luftwaffe began the operation with massive air attacks on airfields and other military targets across the country. Although