The 4th Sejong Policy Forum was held on Thursday, April 14, 2016 at the Somerset Palace Seoul on the subject of “The 2016 Nuclear Security Summit in Washington and the ROK-U.S.-Japan Security Cooperation.” The forum was conducted in two separate sessions—each on the theme of “Assessing the Current Situation on the ROK-U.S.-Japan Security Cooperation,” and “Tasks for Future ROK-U.S.-Japan Security Cooperation,” respectively. Vice President Sang Hyun Lee of the Research Planning Division moderated the first session discussion during which Professor Young-ho Kim from Korea National Defense University and Professor Yang-hyun Cho from Korea National Diplomatic Academy made presentations. President Chang Soo Jin of the Sejong Institute moderated the second session during which Dr. Hwa Sup Song from Korea Institute for Defense Analyses and Professor Wooseon Choi from Korean National Diplomatic Academy presented on the topic. Vice President Un-Chul Yang, senior fellows Soung Chul Kim and Tai Hwan Lee, and visiting fellow Tai Hwan Kwon from the Sejong Institute. And Professor Jae-cheol Kim from the Catholic University of Korea, Professor Heung-gyu Kim from Ajou University, Vice President Kang Choi from the Asan Institute for Policy Studies and Dr. In-Hyo Seol from the Korea Institute for Defense Analyses also participated in the forum as panelists for an active discussion and exchanged their views and expertise.