Sohee Ha is a senior researcher at the Ilmin International Relations Institute (IIRI) and a Ph.D. candidate in International Relations at Korea University. At IIRI, she contributes to research projects on alliance diplomacy, including U.S.–ROK–Japan trilateral cooperation, NATO’s engagement with the Indo-Pacific, and the EU–ROK strategic partnership. Her research focuses on nuclear latency, the credibility of U.S. extended deterrence, and nuclear nonproliferation. Her doctoral dissertation examines the conditions under which non-nuclear allies use nuclear hedging to compel concessions from their great-power patrons. She was also selected for the 2025 cohort of the CTBTO Research Fellowship, where she conducted research on the prospects for the DPRK’s engagement with the organization.