East Asian studies
William J. Duiker is a former United States Foreign Service officer and is currently Liberal Arts Professor Emeritus of East Asian Studies at Penn State University. His area of expertise is East Asia; while in the Foreign Service, he was stationed in Taiwan (the Republic of China), the Republic of (South) Vietnam, and Washington, D.C.. After leaving the State Department in 1965, he received his PhD degree in East Asian studies at Georgetown University.