John Yoo is a professor of law at the University of California at Berkeley School of Law (Boalt Hall) and a visiting scholar at the American Enterprise Institute. From 2001 to 2003 he served as Deputy Assistant Attorney General in the Office of Legal Council in the Justice Department of President George W. Bush. Professor Yoo is the author of a number of books, most recently of Crisis and Command: A History of Executive Power, From George Washington to George W. Bush.