Despite having few allies and experiencing economic hardship, the Democratic People's Republic of Korea (DPRK) continues to conduct military provocations, destabilizing peace on the Korean Peninsula. However, the Republic of Korea (ROK) and the United States (US), the two partners who are superior in terms of national capabilities, are having difficulty deterring the DPRK's aggression. In this context, this article examines the domestic and international factors that reduce the ROK-US alliance's ability to hinder DPRK from conducting belligerent actions that especially threaten the ROK's national security. The first three factors are the DPRK's nuclear weapons, the ROK's domestic politics, and the increasing China-ROK economic ties. Additionally, the rise of China and its potential impact on the ROK-US alliance to deter the DPRK's provocations will be discussed as the fourth factor. By shifting the power dynamics in East Asia and the solidarity of the ROK-US alliance simultaneously, these factors are working as obstacles to the ROK and the US from collaborating for peace on the Korean Peninsula. Thus, unless the ROK and the US find ways to restore their dominance in the region and strengthen their alliance relationship, the DPRK's provocations could become more and more difficult to deter, leading to increased conflict on the Korean Peninsula.