In 1979, a team of lawyers, historians and investigators at the U.S. Justice Department’s Office of Special Investigations were tasked with deporting Nazis from the United States. Today, a 600-page report detailing their activities is under scrutiny—despite the government’s efforts to keep it secret. The most jarring revelation is that American intelligence officials appeared to create a “safe haven” in the United States for Nazis and their collaborators after World War II. While previous reports have acknowledged the C.I.A.’s use of Nazis to collect postwar intelligence, this new document says “the government’s collaboration with persecutors” went so far as knowingly granting entry to former Nazis. The report also details new evidence about more than two dozen of the most notorious Nazi cases over the last three decades.