In February 1945, Winston Churchill, FDR, and Stalin made a decision. They would wipe out the Nazi party. And wipe it out they did. They tackled the Nazi ideology and tore it out, root and branch. They insisted on reconstructing German society without inviting the people who infected it it with Nazism to partake.
This was an imperfect endeavor, carried out by people whose hearts were not always in the right place. After all, the United States made use of Wehrner Von Braun, who was both pivotal to the U.S. space program as well as a user of Nazi slave laborers. Not for nothing did Tom Lehrer sang one of the most delightfully offensive songs of his career, Wernher Von Braun, where he cheerily reminds us of Von Braun's amoral nature as the latter learns Chinese for the sake of a better opportunity.
