Tensions in the Korean Peninsula have soared with the advancement of North Korea’s (DPRK) nuclear weapons development. Along with Russia’s invasion of Ukraine in early 2022, DPRK’s 7th nuclear test is impending. In the era of a “new Cold War,” the presidency of South Korea (ROK) changed in May 2022. This study examined how the recent ROK presidency change affects its security relationship with DPRK. To analyze this, I performed a literature review of DPRK-related policies that former ROK presidents implemented. I used qualitative data from my three in-depth interviews that focused on Yoon’s policy initiatives in three aspects: DPRK policy, US-ROK alliance, military defense. To obtain updated information on ROK’s international situation, I conducted a debriefing of the 8th Yonhap News Symposium on Korean Peace (June 2022). Throughout past ROK governments, the strategies toward DPRK differed significantly between progressive and conservative parties. Inter-Korean relations were stronger under progressive party governments, but neither made progress towards DPRK’s denuclearization. President Yoon stated his policy would be principled and consistent, with a strong US-ROK alliance and international cooperation. Yoon planned the implementation of ROK’s 3-axis system and the establishment of the Military Strategic Headquarters, including advanced detection and precision strike counter-force capabilities. If he can achieve a US-ROK alliance and attain non-nuclear deterrence, ROK’s security relationship with DPRK will likely be safer than in the past. My research addresses a detailed question that is part of a larger global landscape to analyze ROK’s international affairs and gain insight into effective security policies.