In the spring of 2002, members of the Bush administration came to John Yoo, then a deputy Assistant Attorney General at the Justice Department, to help the administration decide where the legal limit was between interrogation and torture.

Yoo wrote what came to be known as ‘the torture memos’ the Bush administration used to delineate the limits of allowable interrogation techniques in wartime. Yoo, now a law professor at University of California at Berkeley, has written a new book that examines the history of executive power, called “Crisis and Command: A History of Executive Power from George Washington to George W. Bush.”