Editing Battle of Britain (section)

===Developing air strategies===
Germany was forbidden a military air force by the 1919 [[Treaty of Versailles]], and therefore air crew were trained by means of civilian and [[gliding|sport flying]]. Following a 1923 memorandum, the [[Deutsche Luft Hansa]] airline developed designs for aircraft such as the [[Junkers Ju 52]], which could carry passengers and freight, but also be readily adapted into a bomber. In 1926, the secret [[Lipetsk fighter-pilot school]] began training Germans in the Soviet Union.{{sfn|Bishop|2010|pp=18, 24–26}} [[Erhard Milch]] organised rapid expansion, and following the 1933 [[Nazi seizure of power]], his subordinate Robert Knauss formulated a [[deterrence theory]] incorporating Douhet's ideas and [[Alfred von Tirpitz#Second Naval Bill|Tirpitz's "risk theory"]]. This proposed a fleet of [[heavy bomber]]s to deter a preventive attack by France and Poland before Germany could fully rearm.{{sfn|Murray|2002|pp=[http://www.ibiblio.org/hyperwar/AAF/AAF-Luftwaffe/AAF-Luftwaffe-1.html#cn32 6–7]}} A 1933–34 [[Military simulation|war game]] indicated a need for fighters and anti-aircraft protection as well as bombers. On 1 March 1935, the [[Luftwaffe]] was formally announced, with [[Walther Wever (general)|Walther Wever]] as Chief of Staff. The 1935 Luftwaffe doctrine for "Conduct of Air War" (''Luftkriegführung'') set air power within the overall military strategy, with critical tasks of attaining (local and temporary) [[Air supremacy|air superiority]] and providing battlefield support for army and naval forces. [[Strategic bombing]] of industries and transport could be decisive longer-term options, dependent on opportunity or preparations by the army and navy. It could be used to overcome a stalemate, or used when only destruction of the enemy's economy would be conclusive.{{sfn|Murray|2002|pp=[http://www.ibiblio.org/hyperwar/AAF/AAF-Luftwaffe/AAF-Luftwaffe-1.html#cn36 7–9]}}{{sfn|Bungay|2000|pp=36–39}} The list excluded bombing civilians to destroy homes or undermine morale, as that was considered a waste of strategic effort, but the doctrine allowed revenge attacks if German civilians were bombed. A revised edition was issued in 1940, and the continuing central principle of Luftwaffe doctrine was that destruction of enemy armed forces was of primary importance.{{sfn|Overy|2013|pp=42–43}}

The RAF responded to Luftwaffe developments with its 1934 Expansion Plan A rearmament scheme, and in 1936 it was restructured into [[RAF Bomber Command|Bomber Command]], [[RAF Coastal Command|Coastal Command]], [[RAF Training Command|Training Command]] and [[RAF Fighter Command|Fighter Command]]. The last was under [[Hugh Dowding, 1st Baron Dowding|Hugh Dowding]], who opposed the doctrine that bombers were unstoppable: the invention of radar at that time could allow early detection, and prototype monoplane fighters were significantly faster. Priorities were disputed, but in December 1937, the Minister in charge of Defence Coordination, Sir [[Thomas Inskip, 1st Viscount Caldecote|Thomas Inskip]], sided with Dowding that "The role of our air force is not an early knock-out blow" but rather was "to prevent the Germans from knocking us out" and fighter squadrons were just as necessary as bomber squadrons.{{sfn|Bishop|2010|pp=18–24}}{{sfn|Deighton|1996|pp=12–13}}

The [[Spanish Civil War]] (1936–1939) gave the Luftwaffe [[Condor Legion]] the opportunity to test air fighting tactics with their new aeroplanes. [[Wolfram Freiherr von Richthofen|Wolfram von Richthofen]] became an exponent of air power providing ground support to other services.{{sfn|Bishop|2010|p=26}} The difficulty of accurately hitting targets prompted [[Ernst Udet]] to require that all new bombers had to be [[dive bomber]]s, and led to the development of the [[Battle of the Beams|Knickebein]] system for night time navigation. Priority was given to producing large numbers of smaller aeroplanes, and plans for [[Ural bomber|a long-range, four-engined strategic bomber]] were cancelled.<ref name="Luftwaffe Origins" />{{sfn|Bungay|2000|pp=39–40}}