On Tuesday, March 28, the Sejong Institute held 2017 6th Colloquium on the subject of “THAAD.” Moderated by Vice President for Research Lee Sang Hyun, the colloquium was led by the presentation from Director Lee Daewoo, reviewing the necessity of THAAD batteries through the installment of three-axis defense system (KAMD, Korea Air and Missile Defense; Kill-Chain, preemptive strike system; and KMPR, Korea Massive Punishment & Retaliation), addressing the controversies surrounding THAAD deployment in Korea and abroad and the measures to alleviate those controversies. Director Lee emphasized that it is absolutely essential for South Korea to complete the installment of three-axis defense system including missile defense system and deploy THAAD to neutralize North Korea’s nuclear and missile threat under the condition where unilateral nuclear armament or deployment of tactical nuclear weapons is impossible.