Explanation: While the US welcomed many Jewish scientists who fled Nazi Germany (not for humane, but practical reasons - many other civilian refugees were refused and suffered horrible deaths for that very reason), after WW2, a large number of Nazi scientists were offered free tickets to the US through Operation Paperclip, primarily for their rocketry work.
And what Cold War drama would be complete without the mirror effort of the opposing side, in the Soviet Operation Osoaviakhim?
One must imagine some of the NASA office meetings were a bit uncomfortable.