CIA spymaster James Jesus Angleton was one of the most powerful unelected officials in the United States government in the mid-20th century, a ghost of American power. From World War II to the Cold War, Angleton operated beyond the view of the public, Congress, and even the president. He unwittingly shared intelligence secrets with Soviet spy Kim Philby, a member of the notorious Cambridge spy ring. He launched mass surveillance by opening the mail of hundreds of thousands of Americans. He abetted a scheme to aid Israel's own nuclear efforts, disregarding U.S. security. He committed perjury and obstructed the JFK assassination investigation. He oversaw a massive spying operation on the antiwar and black nationalist movements and he initiated an obsessive search for communist moles that nearly destroyed the Agency.