"People use armed force all the time with their neighbors."

No, they really, really don't. Compared with either a). governments or b). people in the ancient world, violence nowadays is really rare. For governments, consider that, in 1900, it was common for a country to spend 10% of its GDP on its military; how many people do you know who spend 10% of their gross pre-tax income on weapons to fight their neighbors with? For people in the ancient world, consider that the murder rate for males before they reached age 25 in pre-agricultural societies was something like 30%; nowadays it's something like 1%.

"On a separate point, while the Nazis had some crazy beliefs, they still excelled in a number of important areas."

Agreed, but what I was saying was that none of these areas involved general intelligence, science, rationality or deliberative reasoning.

"So let's be glad they underrated rationality."

Agreed. My thesis in this post was that rationality, intelligence, and science are the most important factors on the level of a country, but not on the level of an individual. Hence, the Nazis, who were really irrational, succeeded at taking over Germany, but then failed at taking over the world largely through irrational stupidity.