With the substantial progress of denuclearization in the Korean Peninsula after the series of summit meetings, the responses of the 4 major powers become critical factors. In terms of international relations theory, the domestic political process is related to the decision-making process of foreign policy. However, the question is the direction and the degree of influence. This session will discuss the influence of domestic politics of the U.S., Japan, China, and Russia to achieve denuclearization and the peace system in the Korean Peninsula and will provide policy suggestions.