Green previously served as senior vice president for Asia, Japan Chair, and Henry A. Kissinger Chair at the
Center for Strategic and International Studies (CSIS),[6] as well as Director of Asian Studies and Chair in Modern and Contemporary Japanese Politics and Foreign Policy at
Georgetown University.[7] He served as Special Assistant to the President for National Security Affairs and Senior Director for Asian Affairs at the
National Security Council (NSC) from January 2004 to December 2005 under
George W. Bush. He joined the NSC in April 2001 as director of Asian affairs responsible for Japan, Korea, and Australia/New Zealand.[8] From 1997 to 2000, he was senior fellow for Asian security at the
Council on Foreign Relations, where he directed the Independent Task Force on Korea[9] and study groups on Japan and security policy in Asia.[10] He served as senior adviser to the Office of Asia Pacific Affairs at the
Department of Defense in 1997 and as consultant to the same office until 2000.[11]
In August 2016, Green was one of fifty senior
GOP national security officials who signed a letter saying they will not vote for
Donald Trump, then Republican nominee for president.[12]
Green speaks fluent Japanese and spent over five years in Japan working as an
Assistant Language Teacher on a precursor to the
JET Programme,[13] as a staff member of the
Diet of Japan, as a journalist for Japanese and American newspapers, and as a consultant for U.S. business.