Tyler Drumheller served for three decades as a field case officer in the CIA's Directorate of Operations, rising in the late 1990s to head what was then the CIA's largest field office. After spending most of his career in the foreign field, Drumheller returned to Washington in 2001, where he served as Chief of Europe until his retirement in 2005. He is the author of On the Brink and is currently working on a second book dealing with the CIA in the age of modern terror.