Abstract: This study examines the impact of China’s growing territorial ambitions on Japanese public opinion. By experimentally manipulating perceived territorial threats from China, we tested two potential mechanisms of increased support for a conservative incumbent leader in Japan. The first is the “rally ’round the flag” model, in which threats universally boost support for the leader through emotion. The second is the “reactive liberal” model, in which support from conservatives remains constant, but threatened liberals move toward supporting the conservative leader. Two survey experiments provided no support for the emotion-based “rally ’round the flag” model, but they lent support for the reactive liberal model in explaining the impact on Japanese public opinion. However, the second experiment indicated that priming with an image of the prime minister that highlights his role as the supreme commander of the national defense forces completely eliminated the gain in approval rates among liberals.