Greg Chaffin is a nonresident fellow with the Atlantic Council’s South Asia Center. He is also a Senior Associate at The Asia Group, a strategic consultancy in Washington, D.C.

Prior to returning to the private sector, Greg worked at the Department of Defense in various roles in the Office of the Undersecretary of Defense for Policy during the Obama and Trump administrations. Most recently, Greg served as the Senior Advisor and Acting Chief of Staff to the Assistant Secretary of Defense for Indo-Pacific Security Affairs. In this capacity, he was the principal policy advisor to the Assistant Secretary on critical political and defense issues spanning 34 countries across the Indo-Pacific. He played a direct role in developing and implementing whole-of-government strategies to advance U.S. interests across the region and led congressional engagement related to the Indo-Pacific. 

While at the Pentagon, Greg also served as the Senior Advisor to the Deputy Assistant Secretary of Defense for East Asia and as Country Director for Korea. In this capacity, he directed initiatives to strengthen the U.S.-Korea-Japan trilateral defense partnership, including efforts to secure a Korea-Japan General Security of Military Information Agreement (GSOMIA) and advance ballistic missile defense cooperation. He also oversaw the development and implementation of initiatives to bolster the U.S.-Korea Alliance. He helped to manage multiple crises involving North Korea, providing advice and support to senior U.S. Government officials. 

Before joining the government, Greg worked at a number of Washington, D.C.-based think tanks, most recently The National Bureau of Asian Research (NBR). As the Project Director for the Political and Security Affairs Team, he led multiple research initiatives, including on strengthening U.S. alliances and partnerships, China’s military modernization, and regional nuclear dynamics.

Greg holds a Master of Arts in Security Studies from Georgetown University’s Edmund A. Walsh School of Foreign Service, and a Bachelor of Arts in Political Science from the University of Rochester.