“Before the war, Hoover had maintained a number of friendly ties with Hitler's police officials. Among other examples, he sent Hitler's Gestapo chief Heinrich Himmler a personal invitation to attend the 1937 World Police Conference in Montreal. The following year, he welcomed one of Himmler's top aides to the United States, and we now know that after the war he embraced "former" Nazis into his Red-hunting FBI apparatus.”