This study examines the relationship between national sentiments and citizens’ attitudes in Japan toward the use of force against China. More specifically, the present research explores how patriotism and nationalism influence citizens’ opinions of using force in defending the Senkaku Islands. Since nationalism entails a sense of superiority to other states while patriotism does not, it is possible to hypothesize that it is nationalism, rather than patriotism, that critically boosts citizens’ support for a more hawkish option. The statistical analyses relying on the survey data in Japan verify this proposition. By dissecting the delicate relationship between national sentiments and citizens’ attitudes toward the use of force, this study significantly advances our understanding of Sino-Japanese relations, thus providing critical implications that are highly relevant in the region.