"The dilemma before Hitler is that he must marshall all his air strength to crush Russia. He cannot do so without weakening his air units in France or the Mediterranean. Such a move would threaten him either with an Allied invasion of the Continent or the disruption of the Axis supply lines to Africa... The Luftwaffe had lost 15,000 planes in Russia - and with them the hope of regaining air superiority in Russian skies."
Click here to read about the German concept of Blitzkrieg.
More about Air Marshall Harris can be read here...
