Professor Koh is currently teaching North Korean Studies at Dongguk University and he is also the Director of the Institute for North Korean Studies. Starting from 2017, he has been working as the Chairman of the planning committee in the National Unification Advisory Council and Chairman of the policy advisory committee at the Office of National Security. Prior to his position as the Director of the Institute for North Korean Studies, he worked as a Committee member of Unification Preparation, Chairman of the North Korean Research Association, Committee on the Development of Inter-Korean Relations at the Ministry of Unification, working in various fields.