When deciding whether to support a military operation, do citizens in democracies weigh whether soldiers themselves support the operation? Recent research has concluded that, in the United States, public support for military operations rests in part on people’s beliefs that soldiers favor their own deployment. However, it is not known whether this finding extends beyond the United States to democracies with diverse national citizenship discourses and threat profiles, and its theoretical basis is not well understood. This article addresses both these gaps. Using novel survey data and an experiment in four democracies with divergent citizenship traditions—France, Israel, the United Kingdom, and the United States—we show that, in all four nations, support for military operations depends significantly on whether people believe that soldiers themselves favor the operation. We highlight two reasons: (1) battlefield performance (respondents think that soldiers who favor their mission fight better), and (2) soldier consent (humans’ capacity for empathy makes them sensitive to whether soldiers are willingly sent into harm’s way). This article has significant implications for debates on public support for the use of military force, the nature of citizenship in modern democracies, and contemporary militarism.