Professor Sun-Jin Lee was a career diplomat, and his last position was Ambassador to Indonesia, 2005-2008. Before that was Deputy Foreign Minister for Policy Planning and International Organizations at MOFA. He had been posted to the Korean diplomatic missions in the USA, China (Beijing, Shanghai & Hong Kong), and Japan. He is currently affiliated as a counsel with the Center for ASEAN-Indian Studies, National Diplomatic Academy, MOFA, while being a research professor for the Institute for East Asia Studies (SIEAS), Sogang University in Seoul. He has been lecturing at the Graduate School of International Studies, Sogang University, since 2009, and also at Seoul National University since 2014. He has devoted himself to research and writings on the topics of regional cooperation in East Asia, in particular, the regional integration in Southeast Asia.