Isn’t there a fundamental logic error in this argument? Hitler would, absolutely have OK’d a nuclear weapons research program if he hadn’t already made refugees of the world’s best minds on the subject, and neither Einstein, Szilárd or Roosevelt could have possibly known Hitler’s thinking on the subject… indeed the world knew nothing about Hitler’s mind until well after Hitler blew that mind across Hitler’s couch.

This cautionary tale only works in hindsight, once you know the history of actions not taken in the past and which didn’t happen behind the fog of war.