Book excerpt: Leon Panetta has had two of the most consequential careers of any American public servant in the past fifty years. His first, beginning as an army intelligence officer and including a run as one of Congress's most powerful and respected members, lasted 35 years and culminated in his role as Clinton's budget czar and White House chief of staff. He then 'retired' to establish the Panetta Institute,to serve on the Iraq Study Group; and to protect the California coast. In 2009 he accepted what many said was a thankless task: returning to public office as the director of the CIA.