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 Polish air force fought with skill and bravery, it was quickly overwhelmed by superior numbers. Soon afterwards the Polish army buckled under the coordi­nated onslaught of hundreds of Panzer tanks and Stuka dive-bombers.24

This campaign first showed the world what synergies were possible in coordinated air and ground operations. Interdiction bombing made it impos­sible for the Poles to move troops in the open, and German armored forces quickly advanced, enveloping the Polish formations. At that point, close air support (CAS) was instrumental in crushing Polish efforts to break out of the encirclements. By the end of September, the Polish army and air force had been destroyed and Warsaw bombed into capitulation. But the small, ill-equipped Polish air force was no real challenge to the Luftwaffe—the real test came the following spring in the Battle of France.25

In May 1940 the German Army overran Luxembourg and drove multi­ple spearheads into the Netherlands, Belgium, and Northern France. As in the Polish campaign, the Luftwaffe struck airfields hard and fast, destroying a large percentage of French and Belgian aircraft on the ground. The Germans used the vertical dimension in novel ways, dropping airborne forces to seize key bridges on the Meuse and behind Dutch defenses in the canal country, and car­rying out a bold glider assault, landing on the roof of the Belgian fort of Eben Emael to unhinge defenses there. Meanwhile, Stuka dive-bombers pounded French, British, and Belgian forces ahead of German armor divisions as the Panzers plunged into Belgium and France. The results in this campaign resem­bled those in Poland the previous September. In the face of a rapid, coordi­nated assault, the defenders buckled physically and morally. The campaign was over in 6 weeks. Although Germany employed airpower similarly in subse­quent campaigns, often achieving tactical success, its ability to translate those achievements into strategic effects diminished as the war progressed.26

In the summer of 1940, with the continental Allies in Western Europe defeated, German leaders began planning operation “Sea Lion,” the invasion and conquest of Great Britain. Such an effort would have presented a unique challenge for German campaign planners in terms of their ability to inte­grate Luftwaffe operations with those of two other services, but their ability to meet that challenge was never tested. Before the German army and navy could launch a cross-channel operation with any chance of success, the Luft­waffe would have to neutralize Britain’s RAF and win command of the air. It failed to do so.

The Luftwaffe launched the main air assault on August 13. Although it gave the outnumbered RAF a considerable pounding for several weeks, the British held on tenaciously, rationing Fighter Command’s limited resources in a sector defense scheme made possible by the use of radar to detect incoming attackers and direct fighter interceptions.27 Even so, the Luftwaffe still might have exhausted RAF resistance had not Adolf Hitler, in a fit of pique in early September, redirected the German air effort away from the RAF bases and against London instead, in an effort to break British resolve with terror bomb­ing. That effort failed as well. By September 17, it was clear that the Luftwaffe would be unable to secure the skies over Britain and the English Channel and Hitler “postponed” plans for Sea Lion.28

Blunted in the west, Germany turned east once more in 1941, unleash­ing Blitzkrieg on the Soviet Union. As in previous campaigns on the continent, the Luftwaffe quickly decimated Soviet airpower, destroying 1,200 aircraft the first day alone. Moreover, the Red Army, immense but stripped of compe­tent leadership in Stalin’s recent purge, lost more than 50 divisions in the first three weeks of battle.29 Yet despite the fact that the Germans drove the Red Army from Poland to the outskirts of Moscow over the course of a few short months, the Soviet will to resist never wavered. The Russians held out, rebuilt their army and air force (with considerable U. S. material support), and turned the tide, eventually driving the Wehrmacht to Berlin and destroying it with the Soviet Union’s own doctrine for integrating airpower with ground forces at the operational level of war—deep battle.30

A more balanced mix of strategic and tactical airpower application char­acterized the Anglo-American airpower experience in World War II, though American and British thinking sharply differed over the fundamental nature of strategic air operations. Soon after the United States entered the war in Decem­ber 1941, the U. S. Army Air Forces (the USAAF, established in 1941 from the prewar U. S. Army Air Corps) had its opportunity to put its strategic bombing doctrine in action. With France fallen, Britain driven off the continent, and the Soviet Union refusing to allow Allied personnel on Soviet territory, the U. S. Army had no immediate foothold from which it could launch an operation against German ground forces, and the only way the United States could strike at its principal European enemy was to join the RAF in the strategic bombing of German industry.

As a result, prewar Air Corps doctrine was the guiding principle when four former ACTS faculty members drafted Air War Planning Document 1 (AWPD-1), the blueprint for U. S. participation in the bombing campaign—the USAAF would use high-altitude, daylight precision bombing to attack Germa­ny’s industrial web. Such an approach was inconsistent with that used by the RAF, which had already tried daylight bombing and switched to nighttime area bombing after suffering unbearable losses. However, the two doctrines were not incompatible, and the Anglo-American Allies eventually agreed to a Com­bined Bomber Offensive (CBO) in which the USAAF would bomb by day and the RAF by night, thereby putting the maximum pressure possible on Germa­ny’s industrial infrastructure and the forces defending it.31

Thus began the first sustained test of the strategic bombing theories developed between the wars.32 Over the next 3 years, the Allies dropped over 2.7 million tons of bombs on industrial targets, first in German-occupied West­ern Europe and later in Germany itself. While the British effort was devoted to crippling German industry by area-bombing urban areas and industrial centers, the USAAF, guided by ACTS industrial web theory, sought to bring German war production to a halt by using precision bombing to destroy key nodes in the system. While they were confident in their ability to do this, the question that arose repeatedly throughout the war was, just what were the key nodes on which German industry most depended? Opinions differed over the course of the strug­gle, and though target lists never focused on one category exclusively, the weight of effort shifted from the aircraft industry in early 1943 to ball bearing plants later that year. In early 1944 the bombing came to focus more heavily on trans­portation and other targets in preparation for the Normandy invasion. Mid-1944 saw a shift once again to steel and, most significantly, synthetic oil production. While the destruction of none of these targets succeeded in bringing Germany’s industrial production to a halt early enough to end the war before its armies were defeated on the ground, the United States Strategic Bombing Survey (USSBS) later concluded—both from physical and documentary evidence, and from the interrogations of key German military, civilian, and industrial leaders—that the attacks on fuel production had the most dramatic impact. Indeed, some analysts have since argued that strategic bombing might have had war-winning effect if synthetic fuel production had received a far greater weight of effort earlier.33

Strategic bombing was by no means the only way airpower was employed in the western theater in World War II. Beginning with the 1943 North Africa campaign and continuing with the invasions and reconquest of the European continent, airpower provided essential support to ground operations in all the basic missions pioneered in World War I: reconnaissance, air superiority, close air support, and interdiction. Along the way—and often through costly errors, such as the debacle at Kasserine Pass in North Africa, which resulted in airmen being given greater responsibility and authority in the conduct of air-ground operations, based largely on earlier RAF experience in the Western Desert— the Allies learned important lessons that became central tenets of U. S. Air Force and RAF doctrine in future years.34 Chief among them was that airpower must never be divided into “penny packets” and dispersed to the control and support of individual ground commanders. Rather, its control must be cen­tralized under the command of an airman, the only military professional who could be entrusted to sufficiently understand its unique properties and employ it effectively, to allow for the most flexible employment and the most effec­tive massing of force against key targets. Most importantly, command of the air is essential: air superiority is a prerequisite for effective surface operations. Though controversial at the time, both of these tenets have endured and are accepted as core prerequisites even today, in the era of hyper-jointness charac­teristic of contemporary American and coalition military operations.35

The air war in the Pacific theater yielded similar lessons, though it unfolded in an order opposite that in Europe. With Japan having captured a broad defensive perimeter of islands in the first months of the war, its home islands were protected by an expanse of ocean that exceeded the range of U. S. bombers. Consequently, the USAAF was first tasked with providing support to Chinese forces in their struggle against the Japanese army on the Asian main­land and to U. S. Army and Marine ground operations in the systematic recon­quest of islands in the southwest Pacific. By late 1944, however, the Marianna Islands had been recaptured and bases built on Guam, Saipan, and Tinian, put­ting Japan in striking range of B-29 heavy bombers.

Once again, ACTS industrial web theory-based Air Corps doctrine guided the effort, at least initially. For the first several months, the USAAF’s XXI Bomber Command attempted high-altitude daylight precision bombing with high explosives, but the characteristically strong winds found at altitudes above 30,000 feet (the so-called “jetstream” blowing west-to-east over Japan and the Pacific) and Japan’s dispersal of industry rendered that approach inef­fective. Therefore, in March 1945 the XXI Bomber Command changed tactics, resorting to nighttime raids at low altitude using incendiaries on urban cen – ters.36 The results were devastating. Over the next 5 months, B-29s dropped 104,000 tons of bombs, destroying an average of 40 percent of the built-up areas in Japan’s 66 largest cities.37 Yet despite this horrific pounding, Japanese leaders were unwilling to accept Allied demands for unconditional surren­der until after the USAAF dropped atomic bombs on Hiroshima on August 6 and Nagasaki on August 9. The surrender finally came on August 14, 1945. In the eyes of U. S. airmen, theories espousing the employment of airpower as an independent war-winning weapon had finally been validated.