Operation Paperclip was the Office of Strategic Services (OSS) program used to recruit the scientists of Nazi Germany for employment by the United States in the aftermath of World War II (1939–45).
There was only one problem: it was illegal. U.S. law explicitly prohibited Nazi officials from immigrating to America—and as many as three-quarters of the scientists in question had been committed Nazis.
Following the discovery of flying discs (foo fighters), particle/laser beam weaponry in German military bases, the War Department decided that NASA and the CIA must control this technology, and the Nazi engineers that had worked on this technology.
Military Intelligence “cleansed” the files of Nazi references. By 1955, more than 760 German scientists had been granted citizenship in the U.S. and given prominent positions in the American scientific community. Many had been longtime members of the Nazi party and the Gestapo, had conducted experiments on humans at concentration camps, had used slave labor, and had committed other war crimes.