8. American University
Program size: 800+
Program cost: $25,764
Star professors: Amitav Acharya, Phillip Brenner, James Goldgeier
AU's School of International Service provides a dedicated international peace and conflict resolution program, which began after students requested more conflict-resolution classes in the 1980s. It's a fitting move from a school that declared its mission was to prepare students to "wage peace" globally upon its founding in 1957.