What explains right-wing radicalization in the United States? Existing research emphasizes demographic changes, economic insecurity, and elite polarization. This paper highlights an additional factor: the impact of foreign wars on society at home. We argue communities that bear the greatest costs of foreign wars are prone to higher rates of right-wing radicalization. To support this claim, we present robust correlations between activity on Parler, a predominantly right-wing social media platform, and fatalities among residents who served in U.S. wars in Iraq and Afghanistan, at both the county and census tract level. The findings contribute to understanding right-wing radicalization in the US in two key respects. First, it examines widespread, nonviolent radical-right activity that, because it is less provocative than protest and violence, has eluded systematic measurement. Second, it highlights that U.S. foreign wars have important implications for domestic politics beyond partisanship and voting, to potentially include radicalization.