Every day, a member of the CIA presents to the president a report detailing the most sensitive activities and analysis of world events. These can range from the behavior of America's allies to the maneuvering of its adversaries, from imminent dangers to long-term strategic opportunities, and are often based on the words of highly placed sources or the interceptions of astonishingly nimble technologies.

This report - for the president's eyes only-forms the basis of the president's assessment of US intelligence and strength. The story of the President's Daily Brief-the PDB, in the jargon-is a window into the character of each president and his administration, and the degree to which his worldview and policy was shaped by the information from the security services.

It is a story that could only be told by a trusted insider. David Priess served during the Bill Clinton and George W. Bush administrations as an award-winning intelligence officer, manager and daily intelligence briefer at the CIA. The CIA, despite its mission of secrecy, has diligently declassified and posted millions of pages of raw intelligence reports, analytic assessments, and memos from the late 1940s through the 1980s. These agency papers have been awaiting examination in a nondescript corner of the CIA's public website. Many more sit on an antiquated database terminal at the National Archives annex in College Park, Maryland.

Few people know such documents exist. Fewer still have made the effort to dig through them as Priess has, hauling in never-before-revealed insights about the PDB. The information base for this book includes largely untapped oral histories, memoirs from PDB recipients and intelligence leaders, publicly released CIA internal studies, and tidbits about key personalities and locations from previously published works.