War II. Historian Richard Melzer now sheds new light on how security at Los Alamos broke down-not by examining this isolated site in New Mexico from the outside as many other authors have-but from within Los Alamos itself. Using interviews, memoirs, and formerly confidential files Melzer shows that spies quite easily obtained security clearances, gained access to top secret information, and carried this information to their Soviet contacts without a hitch. What Melzer tells us about the flaws of security in the past might well help those in charge of security today as the United States grapples with these problems in the aftermath of the Chinese espionage scandal that rocked Los Alamos and the American intelligence. Photographs, index, bibliography.