Willy Ley was a German rocket scientist who left Germany in 1935 and ended up int the U.S. during WWII. When Operation Paperclip brought over Nazi Germany's rocket scientists, the U.S. had the option to put a known anti-nazi German rocket scientist in to be von Braun's boss, or let a collaborator run the U.S. rocket development program. I think we made the wrong choice.

https://en.wikipedia.org/wiki/Willy_Ley