John Choon Yoo is a Korean-American attorney, law professor, and author. Yoo is currently the Emanuel S. Heller Professor of Law at the University of California, Berkeley. Previously, he served as the Deputy Assistant U.S. Attorney General in the Office of Legal Counsel, Department of Justice (OLC), during the George W. Bush administration. He is best known for his opinions concerning the Geneva Conventions that attempted to legitimize the War on Terror by the United States. He also authored the so-called Torture Memos, which concerned the use of what the Central Intelligence Agency called enhanced interrogation techniques including waterboarding.