The 2019 ASEAN-Republic of Korea Commemorative Summit was held in Busan from November 25-26 to celebrate the 30th anniversary of ASEAN-ROK dialogue relations. The summit – a high point of President Moon Jae-in’s New Southern Policy (NSP) since his announcement of the policy in November 2017 – produced several achievements. Many MOUs were signed; bilateral summits were held between the ROK and several key ASEAN countries, including Indonesia, Malaysia, the Philippines, and Vietnam; and perhaps most importantly, the inaugural Mekong-ROK Summit was launched, which marked the institutionalization of South Korea’s increasingly active roles and productive ties with the five mainland Southeast Asian countries of Cambodia, Laos, Myanmar, Thailand, and Vietnam. These outcomes serve to deepen South Korea’s expanding partnerships with Southeast Asia at both bilateral and multilateral levels. All in all, the summit added a feather to Moon’s NSP cap, recording yet another milestone after the president’s successive visits to all ten ASEAN countries the past two years (the first Korean leader to do so).