• 2004-2005: Senior Director, Asian Affairs, National Security Council (NSC), USA
• 2001-2003: Director, Asian affairs with responsibility for Japan, Korea, Australia, and New Zealand, National Security Council (NSC), USA
• 1999-2000: Acting Director, East Asian Studies, Edwin O. Reischauer Center, SAIS, Johns Hopkins University, USA
• 1997-2000: Senior Fellow, East Asian Security, Council on Foreign Relations, USA
• 1997-2000: Consultant, Office of Asia Pacific Affairs, Department of Defense, USA
• 1997: Senior Adviser, Office of Asia Pacific Affairs, Department of Defense, USA
• 1995-1997: Research Staff Member, Institute for Defense Analyses, USA
• 1994-1995: Assistant Professor, Asian Studies, SAIS, Johns Hopkins University, USA
• 1992-1994: Associate Executive Director, Foreign Policy Institute, SAIS, Johns Hopkins University, USA