These were indeed scientists previously held captive by the ****'s, and who escaped thanks to intervention from American soldiers, facilitated by the brother of Wernher von Braun. I suspect we all know that story.
Held captive by the Nazis ? Who told you that, the fairy fee ? Or is this history written by victors ?
Von Braun was a member of the **** party, not because he believed in those ideas, but to advance his own career. He has seen with his own eyes in wat conditions the REAL prisoners of war had to build the rockets he designed, and how many died. He knew and didnt object. That was why he was a controversial figure for the US senate.
Von Braun surrendered to the US army because he thought with the USA he had the best odds to continue working on his lifelong dream of manned space flight.
When he and his 127 head strong team arrived in the USA, they were brought to Fort Bliss and guarded with arms; Because the war was over, they called themsel "Prisoners of Peace" It was not untill 1955 that he was granted American citizenship.
When the Russians launched Sputnik and succeeded, the US navy got a shot at launching a rocket but it blew up. Only then, President Eisenhower turned NACA into NASA, gave it authority over the ICBM program and Von Braun and his team of 127 German PoWs got a chance. Before that, the US Senate and army objected to Von Braun and their team because their war past was unclear. They were never investigated because the authorities feared that the team would no longer cooperate and share their knowledge if an investigation was started.
If you really want some interesting facts from all sides, the four part BBC documentary "Space race" is on Youtube.
On the Soviet side, Sergey Korolev endured some hardships too, Stalin sent him to the Gulag during the Great Purge, but when his rival who ratted him out couldnt get it done, they brought him back from the Gulag and he became program leader. He had life long health issues from his hard time in the Gulag.