This lesson introduces the ideas of Guilio Douhet, Billy Mitchell, and Hugh Trenchard, recognized today as the three premier airpower theorists and advocates of the time. This lesson also examines the airpower theory developed by the US Army’s Air Corps Tactical School (ACTS). These pioneers, guided by the experiences of WWI and newly available technologies, formulated theories for employing airpower to strike at the heart of an enemy’s war-making ability and potential. ACTS became the "think tank" for US Army air ideas, and its instructors and students became America’s World War II airpower leaders. There is also a short introduction/review of analytical tools to supplement the Campaign Planning Model in helping the student understand reasons for the success and failure of campaigns in WWII and after.

LO 502.1 Comprehend Douhet’s, Michell’s, and Trenchard’s key airpower concepts.

SOB 502.11 Identify their theories and ideas regarding airpower.

General Giulio Douhet (born in 1896) of Italy was among the first persons to think deeply and write about airpower and its role in war. His formula for victory—gaining command of the air, neutralizing an enemy’s strategic "vital centers," and maintaining the defensive on the ground while taking the offensive in the air—underpinned coalition strategy during the Persion Gulf War of 1991.

Douhet predicted that "the skies are about to become a battlefield as important as the land or the sea". He advocated the creation of a separate air arm, commanded by airmen. He said, "To gain command of the air is to be able to attack with impunity any point of the enemy’s body." Douhet argued that airpower was revolutionary because it operated in the third dimension, unhampered by geography. In Douhet’s eyes, the best defense—indeed, the only defense—was a good offense. He therefore stated "I am against air defense because it detracts means from the Air Force … I am against it because I am absolutely convinced that … it cannot achieve its aim." These beliefs regarding the nature of modern war and the inherent characteristics of the airplane led Douhet to a theory of war based on the dominance of airpower.

Douhet identified five basic target systems as the vital centers of a modern country: industry, transportation infrastructure, communication nodes, government buildings, and the will of the people. He stated "Once a nation has been conquered in the air it may be subjected to such moral torture that it would be obliged to cry ‘Enough’ before the war could be decided upon the surface". He saw little use for "auxiliary aviation" (pursuit or attack aircraft).

Douhet took a decidedly nonromantic view. No passages in his writings speak of the exhilaration of flight, the conquest of nature by man and machine, or the near-mystical experiences of people who have become unfettered by the tyranny of geography. He did not compare pilots to modern knights.

He envisioned aircraft conducting area attacks would use a mixture of high-explosive, incendiary, and gas or biological (aerochemical) bombs. The explosives would produce rubble; the incendiaries would start fires in the rubble; and the aerochemical bombs would prevent firefighters from extinguishing the blaze.

He argued that the government must subsidize and support civil aviation in three general ways. First, it should establish air routes. Second, it must fund research and development. Third, Douhet believed that civil airliners should be capable of performing military missions.

Hugh Trenchard: The object of war was to force an enemy to bend to one’s will, accomplished by breaking either his will or his capability to fight. Armies were generally condemned to concentrate on the latter by seeking battle. Hugh Trenchard, the first chief of the RAF and its commander from 1919 to 1930, focused instead on the "will" portion of that equation. Trenchard believed that the airplane was an inherently strategic weapon, unmatched in its ability to shatter the will of an enemy country. In a memo of September 1916, he wrote that the aeroplane was an inherently offensive weapon. One had to guide the aeroplane "by a policy of relentless and incessant offensiveness".

He envisioned an air campaign focusing on what today we would term "interdiction" targets: railroad marshaling yards, bridges, supply depots, and road networks that provided men and material for the front. Trenchard stated that the psychological effects of bombing outweighed the material effects at a ratio of 20 to one. The real key to the concept of strategic airpower espoused by Trenchard was the selection of targets. He believed that attacking "legitimate objectives" in populated areas was permissible, although one must take "all reasonable precautions" to spare hospitals and other privileged buildings. Trenchard presented a theory of strategic airpower that identified enemy morale as the key target, and then institutionalized those ideas through a series of doctrinal manuals. These precepts were subsequently taught and refined at another of Trenchard’s creations—the RAF Staff College. He was the "father of the RAF".

More than any other individual, Billy Mitchell was responsible for molding the airpower convictions that would serve as the doctrinal cornerstones of the United States Air Force. Perhaps Mitchell’s most lasting contribution to the development of American airpower was his welding the notion of air force autonomy to a progressive view of "independent" air operations, such as strategic bombing, that aimed to achieve independent results rather than simply support land or sea forces. He had established relationships with Trenchard and Douhet. His technical bent manifested itself in Mitchell’s later predictions regarding such exotic innovations as cruise missiles, glide bombs, jet propulsion, supersonic flight, and space travel. His vision was one of aerial knights engaged in a chivalrous contest and supported by the population at large. This romantic notion was both incongruous and appealing after the horrors of trench warfare. (contrary to Douhet). He differed from Tenchard and Douhet with his emphasis on the primacy of pursuit. He vacillated about the propriety of bombing civilians. He advocated burning Japanese metropolitan areas in the event of a war with Japan, and noted that poison gas could be used to contaminate water supplies and spur evacuations from cities. Much of Douchet’s and Mitchell’s writing was similar.

LO 502.2 Comprehend how air power doctrine evolved at the Air Corps Tactical School (ACTS).

A strategy was undertaken to ensure that American airpower realized its full potential; early air leaders and thinkers such as Mitchell, Patrick, Gorrell, Milling, Sherman, Benjamin "Benny" Foulois, and Henry "Hap" Arnold haltingly developed an ad hoc, four-part strategy designed either to create new roles and missions for the Air Corps or to steal old responsibilities away from the Army and Navy. Specifically, the strategy sought to (1) redefine America as an airpower rather than a maritime nation; (2) demonstrate and publicize the versatility of airpower in peacetime roles; (3) create both a corporate Air Corps identity through political maneuvering and an independent air force through legislation; and (4) perhaps most importantly, develop a unique theory of air warfare—unescorted high-altitude precision daylight bombardment (HAPDB) against the key nodes of an enemy’s industrial infrastructure.

1. To redefine, ACTS took on a large redefining campaign: they invented "Chess Air" games; conducted public promotions for example with Babe Ruth catching baseballs dropped from aircraft; they participated in county fairs, formed the first aerial demonstration team and won (Jimmy Doolittle) repeated victories at national air races; they developed stories about a young aviator named Bill Bruce who protrayed patriotic values.
2. ACTS demonstrated versatility by patrolling the entire Mexican border, conducting aerial mappng along the Mississippi, provided disaster relief, and conducted mail services briefly. They worked to define the need to protect domestic shores, and make the case that the Navy was not the best way to do this. The industrial triangle represented a weakness which needed protection. However, by defining defense through air protection, long-range and land-based airpower offered a better solution, thus expanding ACTS claims even farther. Much help was received by FDR.
3. ACTS also conducted a political and legislative assault. There were many failures along the way. Foulois alone, for example, testified seventy-five times before he became leader of the Air Corps!
4. ACTS was the most important contributor to the concept of unescorted High Altitude precision daylight bombardment (HAPDB). They did this through their 3 phases of ACTS development (1- established primacy of bomber, 2- establishment of HAPDB theory, 3- set theory to doctrine).

The Air War Strategy that developed from these events: In July 1941 President Roosevelt tasked the armed services to write a war plan that would provide the number of men and equipment initially needed to win a future war against the Axis powers. The person who wrote this was an ex-bomber mafia (ACTS leader) who brought significant ACTS doctrine into this plan. From this, he wrote AWPD-1, the air annex to the plan FDR requested. This document was then turned into a strategic blueprint for air warfare in Europe. This effort, coupled with the interwar success of the Air Corps in a broader four-part strategy, ensured that the Army Air Forces would become what the aeromaniacs had always wanted—an independent service with an independent mission.

Phase two of the Tactical School’s doctrinal development (1927-34) is where this doctrine was primarily developed. In particular, the Combined Air Force text codified five crucial propositions of air warfare for Army airmen. First, the ultimate goal of any air attack is "to undermine the enemy’s morale [or] his will to resist." Second, airmen can best destroy morale by attacking the interior of an opponent’s territory. Attacks against vital points or centers will not only terrorize populations into submission but also save lives. (In M-day warfare, there is no need for battles of attrition or annihilation.) Third, airpower is an inherently offensive weapon that is impossible, in absolute terms, to stop. Fourth, since airpower is the only military tool that can hit distant centers of concentration and sources of supply and since it is the only tool that can undermine national morale with minimum effort and materiel, combatants should use it extensively in strategic operations. Strategic targets, after all, are almost always more important than tactical targets. Last, "In any scheme of strategical operations the object is to cause complete destruction or permanent and irreparable damage to the enemy which will have a decisive effect."

LESSON MATERIALS: (Total page count—76, video viewing 1:46 min.)

1. Lesson Overview Video Lecture, 1:46 min. (All)
2. Meilinger, "Giulio Douhet and the Origins of Airpower Theory," AS CB, pg 49-69. (LO 502.1)
3. Meilinger, "Trenchard, Slessor, and the Royal Air Force Doctrine before World War II," AS CB, pg 70-86. (LO 502.1)
4. Clodfelter, "Molding Airpower Convictions: Development and Legacy of William Mitchell’s Strategic Thought," AS CB, pg 87-102. (LO 502.1)
5. Faber, "Interwar US Army Aviation and the Air Corps Tactical School: Incubators of American Airpower," AS CB, pg 103-124. (LO 502.2)
6. Slide presentation, "Doctrine Evolutionary Loop and other AS Tools," AS CD, 5 slides.
   (LO 502.1, 502.2)

The lesson overview video previews AS 502: The Interwar Airpower Theorists lesson.

All the readings come out of the book The Paths of Heaven and they each provide a good summary of the life and theories of Douhet, Trenchard, Mitchell, and the leaders/instructors and theories of ACTS.

The slide presentation on the doctrine evolutionary loop provides insight on how doctrine should develop and how it sometimes stagnates into dogma. A summary of other Airpower Studies’ tools is also provided.

This lesson presents the seminal theories that formed airpower during the interwar period. These theories take what was learned during World War I as the basis for strategies which will prevent positional warfare in the future, use airpower to its best advantage, and encourage the independent organization of airpower.

ACSC/DLC, Airpower Studies Division, DSN 493-6180