In The Secret Sentry, Matthew M. Aid traces the growth of the NSA in 1945 through critical moments in its history. Aid, a visiting fellow at the National Security Archives, explores the agency’s connection to the intelligence failure that occurred when evidence that NSA officials called “ambiguous” was used as proof of Iraqi WMD capability. He also details the intense debate within the NSA over its growing role under the Bush administration to spy on U.S. citizens.