Tim Weiner’s “Legacy of Ashes” is the hidden history of the CIA: why eleven presidents and three generations of CIA officers have been unable to understand the world; why nearly every CIA director has left the agency in worse shape than he found it; and how these failures have profoundly jeopardized our national security. Tim Weiner is a reporter for The New York Times. He has written on American intelligence for twenty years, and won the Pulitzer Prize.