Battle of Smolensk
Hillgruber argued that these assumptions about the Soviet Union shared by the entire military elite allowed Hitler to push through a "war of annihilation" against the Soviet Union with the assistance of "several military leaders", even through it was quite clear to the military that such a war would violate all standards of civilized warfare and would be waged in the most inhumane fashion possible. Hillgruber argued that the decisive moment on the war on the Eastern Front was the Battle of Smolensk in July 1941, which was not quite the overwhelming German victory as traditionally depicted, as though the Red Army had taken more losses, the Battle of Smolensk had blunted the German drive onto Moscow, giving the Soviets crucial time to rebuild. Furthermore, Hillgruber was the first historian to point out that the Battle of Smolensk was closely studied in Japan, and led Japanese decision-makers to conclude the Soviet Union would not be defeated in 1941, thereby helping the "Strike South" fraction in the Japanese government gain ascendency over the "Strike North" fraction.