Stalingrad marked the turning point of the war in the East. By this time even Manstein stated that the war in Russian could not be won.

Kursk marked the end of German offensive capabilities in the East. From that point on they were strictly on the defensive. By this time the Soviet offensives started to resemble the German Blitzkrieg in the opening months of Barbarossa........

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The war against Russia will be such that it cannot be conducted in a knightly fashion. This struggle is one of ideologies and racial differences and will have to be conducted with unprecedented, unmerciful and unrelenting harshness. -Adolf Hitler