The Princeton Institute for International and Regional Studies (PIIRS) is the main research center for international studies and area studies at Princeton University and is one of the oldest centers of its kind in the United States. The Institute focuses on an interdisciplinary approach and its associated faculty is drawn from more than 150 professors and other scholars from more than 25 different departments within Princeton. Its director is historian Stephen Kotkin, the John P. Birkelund ’52 Professor in History and International Affairs.