There is some truth to that, but it is largely a myth. Yes, the Nazis studied and experimented with meth and other enhancers (as did every nation involved with the war). But the fact remains: these drugs (like all drugs) degrade, not enhance, a soldiers performance. I remember encountering insurgents in Fallujah who were jacked on similar cocktails: yes, they did not feel the pain and took multiple shots to neutralize but, no, they did not perform better or make better decisions in combat. In fact the opposite was true.