WWII can be seen as just a continuation of WWI with a pause in between 1919 and 1939 or 1937 if you include the conflict between Japan and China. Some German Generals wanted to invade the USSR in steps and plan each operation as progress was made yearly, they were over ruled by the Corporal. One of the most decisive points of WWII was the air war in which Germany lost control of the skies above the battle fields and Germany. This affected production, movement of armaments and troops etc and hindered them on all aspects of fighting the war effectively. Hindered the U-Boats on their transit in the Bay of Biscay and tied up vast numbers of 88 Flak guns and man power to defend Germany which would have been more use at the fronts. Germany's largest fault was having what could be called a purely tactical airforce and no strategic arm to the Luftwaffe. The fighters (Bf 109) were short ranged as they had been designed to be based just behind the front line and the bombers were all medium two engined and were nothing more than flying artillery for the Heer, they also had a very light bomb load. If the Germans had a Stratigic bomber they could of hit the USSR's production centres, mainly the electric power stations and tankograd beyond the Urals. The four engined Fw 200 Condor had series problems and lots broke up either in the air or on landing etc as their design could not take the punishment of military aviation.