Since Korea's transition to democracy in 1987, Korean leaders have become increasingly confrontational toward Japan, with such steps ranging from verbal threats filled with hawkish rhetoric to material threats, such as displays of military force and threats of actually using it. To explain South Korean leaders’ hawkish approach to Japan, we build a theory of “prospective diversion” by combining insights from the diversionary theory of international conflict and prospect theory. We argue that foreign policy leaders have a strong tendency to overvalue political losses relative to comparable gains in their approval ratings. As a result, they are inclined to take risk-seeking diplomatic actions toward foreign adversary to avoid further losses. By conducting statistical analyses and developing case studies of Korean leaders’ confrontational policy decisions regarding Japan, we present empirical findings consistent with our hypothesis that Korean leaders are inclined to engage in prospective diversion toward Japan when they suffer domestic losses. This article provides an enhanced understanding of the domestic political foundation of South Korean leaders’ increasingly contentious attitude toward Japan.