Joby Warrick joined The Washington Post’s national staff in 1996. He has covered national security, the environment and the Middle East and writes about terrorism. He is the author of two books, including 2015’s “Black Flags: The Rise of ISIS,” which was awarded a 2016 Pulitzer Prize for nonfiction. His first book, “The Triple Agent,” recounts the 2009 suicide attack by an al-Qaeda informant on a CIA base at Khost, Afghanistan, that killed seven U.S. intelligence operatives. Before joining The Post, Warrick covered the fall of communism in Eastern Europe as a UPI correspondent and worked as a reporter at the Delaware County (Pa.) Daily Times, the Philadelphia Inquirer and the News & Observer of Raleigh, N.C. While in Raleigh, he co-authored “Boss Hog,” a series of investigative stories that documented the political and environmental fallout caused by factory farming in the Southeast. The series won the 1996 Pulitzer Prize gold medal for public service.