• 2013-2017：Assistant Secretary of State, Bureau of East Asian and Pacific Affairs, Department of State, USA

• 2011-2013：Senior Director for Asian Affairs, National Security Council (NSC), USA

• 2009-2011：Senior Director for Japanese and Korean Peninsula Issues, National Security Council (NSC), USA

• He had assignments as U.S. Consul General in Osaka-Kobe, Japan (2005-2008); Deputy Chief of Mission at the U.S. Embassy in The Hague, Netherlands (2002-2005); Deputy Chief of Mission at the U.S. Embassy in Nicosia, Cyprus (1999-2002); Political Section Unit Chief at U.S. Embassy Seoul, Republic of Korea (1992-95); Political Advisor to the Permanent Representative to the U.S. Mission to the United Nations, Ambassador Pickering (1989-92); Vice Consul in Osaka and Branch Office Manager in Nagoya, Japan (1987-89); and Assistant to the Ambassador to Japan, former Senate Majority Leader Mike Mansfield (1985-87).