One of the biggest mistakes made by Germany was the suppression and Oppression of the Eastern European nations after invasion. In the Baltic states and Ukraine for example, they were greeted as liberators… they squandered their chance to bring these nations into the Axis orbit as minor partners when they treated the locals as sub-human.
Not only did they lose the free co-operation of these nations, but in the end they were fighting a war behind their own lines against all kinds of passive and sometimes active resistance.
Excellent point. I even believe that the entire Nazi racial ideology contributed to the defeat of Germany. The holocaust was not only a horrible crime at a humanitarian level, but it also robbed Germany of many great minds and organizers in science, culture, and economics. Germany’s Jews thought of themselves as Germans, and many fought for Germany in World War I. Instead of keeping all that potential available for the benefit of their country, the Nazis expelled or murdered them. And to do so, they built a gruesome and expensive system of oppression, manned by large numbers of other Germans who could instead have fought at the front.