> What was Hitlers biggest mistake? That as an Austrian he hated the Prussians and by extension many of the people of western and central Europe. > What was Hitlers one biggest mistake? Answered in the previous. As for the war itself, Germany didn't have a chance of winning and should've suffered Geo-political isolation as they worked to rebuild their country and reach out to ethnic Germans globally to build an international political power base. They lacked both the man power and the industrial capacity to win a kinetic war. While their accomplishments both strategic and industrial are amazing, given what they had to work with, it's still overshadowed by the fact that the Axis powers were up against nations with vastly larger populations, more substantial industrial, and agricultural capacities. However, they could've easily held out for decades advancing their country, Italy, and Japan, while waiting patiently for the Anglo-Franco western hegemony to collapse.