The United States has promoted deployment of a THAAD system in the ROK since mid-2014, triggering wide-ranging controversies among the concerned countries and scholars. In fact, the existing Green Pine radar system in the ROK can provide coverage for the whole Peninsula, and a THAAD system with AN / TPY-2X- band radar will not provide significant extra coverage or tracking time for missile defense purposes vis- à- vis the DPRK missile threats and THAAD interceptors cannot protect the northern areas of the ROK including Seoul either.It seems the purpose is to further integrate the U.S.- Japanese- ROK missile defense architecture as a counterweight to China’s deterrence, which will be likely to destabilize the East Asian region and eventually damage the ROK security interests.