John Yoo is a professor of law at the University of California at Berkeley School of Law (Boalt Hall), where he has taught since 1993. From 2001-03, he served as a deputy assistant attorney general in the Office of Legal Counsel of the U.S. Department of Justice, where he worked on issues involving foreign affairs, national security, and the separation of powers. He served as general counsel of the U.S. Senate Judiciary Committee from 1995-96, where he advised on constitutional issues and judicial nominations.