Quite possibly a longer answer than you were expecting but worth a read:
Lessons from World War I and the debates of air power enthusiasts influenced the development of German air war doctrine during the interwar years. L.Dv.16, Luftkriegfuhrung (Conduct of the Air War), was developed in the mid-thirties and was the Luftwaffe's main doctrinal statement. It remained unchanged throughout the war.
Because of its lack of doctrinal prioritization, this manual was not an effective framework for employment of the Luftwaffe during the war. Throughout WWII, Luftwaffe priorities changed frequently, assets were often not concentrated, and the full value of achieving and maintaining air superiority was never appreciated. The brief and dazzling successes in Poland and the west blurred any flaws in doctrine, organization, or operational practice. In the Battle of Britain changing priorities and a failure to achieve air superiority assured the Luftwaffe's defeat.
German military tradition and ideals emphasized operational art, especially the attributes of manoeuvre and flexibility and on tactics. The impact of technology and logistics on warfare received less attention. Yet precisely this emphasis on flexibility and the art of warfare resulted in vague doctrine which undermined the principles of concentration and mass in the employment of Luftwaffe assets. This would lead the Luftwaffe into an attrition war of both aircraft and pilots.
During the interwar years, from the onset of any conflict, the Reich faced the prospect of a major struggle on the ground. In recognition of this strategic position in Europe, the concept of Operativer Luftkrieg (operational air warfare) was developed and embodied integratinq an independent air force into fighting a total war. The key tenet of this concept of air warfare was supporting ground forces. In fact, as late as 1941- 1942 there were few other air forces which could provide ground forces with decisive assistance at a critical juncture in the battle.
Of the inter-war year prophets, only Billy Mitchell argued that fighter support missions were essential to other air operations and stated that the proper aircraft ratio for Air Corps aircraft should be 60% fighter aircraft, 20% bombardment and 20% reconnaissance. Mitchell's ideas in this regard would have little influence on the doctrinal development of the Luftwaffe.
Giulio Douhet, whose treatise Command of the Air was published in 1921, influenced how the Germans thought about air power. The nucleus of his theory comprises three main ideas:
- achieving air superiority
- destruction of enemy centres of gravity through large formations of bombers
- the use of airpower to break the will of the people.
German thinkers embraced his ideas of the need for an independent service and importance of control of the air, but viewed his notions regarding the effects of area bombing as overly optimistic. He rejected the idea that an enemy air force should be fought in the air, but rather by destroying the collection points, the supply, and the manufacturing centers of enemy aviation. He rejected the notion of specialized fighters to defend against enemy bombers, preferring instead to devote all resources to battle planes which could carry out bombardment and be self-defending. These ideas would be reflected in the Luftwaffe throughout much of the war.
The Spanish Civil War, however, highlighted the fact that fighter aircraft would play a crucial role in gaining air superiority. As a result, Ernst Udet, in charge of production by the late 1930s, changed the long run goal for the Luftwaffe's force structure from a ratio between fighters and bombers of 1-3 to a ratio of 1-2.
Bombers were viewed as a primary asset in the battle to gain air superiority by destroying the enemy air forces on the ground. Primarily, however, the Luftwaffe was viewed as an instrument of attack
The Bomber Chief of the Operations Department of the Luftwaffe General Staff, Major Deichmannn, claimed that when in 1936 he called together all General Staff officers and made them write down their definition of the concept, he got as many definitions and interpretations as there were officers present.
The lack of clear-cut doctrinal priorities and ambiguities associated with the concept of operational air war were weaknesses which would manifest themselves throughout World War II.
Not typed verbatim, extracts taken from:
Research paper of
Lt Col H Stoll USAF
Air War College
Maxwell AFB
April 1994