Question: John Choon Yoo (born July 10, 1967) is a Korean-American attorney, law professor, and author, his best known for his opinions concerning the Geneva Conventions that attempted to legitimize the War on Terror by the United States,  is a metaphor of war referring to the international military campaign that was launched by the U.S. government after the September 11 attacks in the U.S. in what year?
answer: 2001