On January 30, 2017, U.S. President Donald Trump and South Korea’s acting President Hwang Kyo-ahn exchanged a phone call in which they reaffirmed their countries’ bilateral alliance and the future deployment of the U.S. THAAD missile defense system to South Korea. According to the White House, “Trump reiterated our ironclad commitment to defend the ROK, including through the provision of extended deterrence, using the full range of military capabilities.” This confirmation that the U.S. will deploy THAAD to South Korea comes after months of doubt regarding whether the South Koreans wanted the missile defense system amidst Chinese disapproval. U.S. Defense Secretary James Mattis reiterated Trump’s commitment on January 31 when he and South Korea’s Defense Minister Han Min-koo similarly discussed North Korean military provocations and repeated both countries’ commitment to deploying THAAD to the peninsula.