Wartime violence and authoritarian repression against civilians take various forms. Past research has explored the causes and consequences of violence, but no previous work simultaneously assessed the long-term effects of different types of violence on political identities. This paper contends that indiscriminate attacks can reinforce ingroup identity, whereas the role of civilian agency in selective violence may have a detrimental impact. Equipped with original data capturing municipality-level exposure to both selective and indiscriminate violence during the Spanish civil war (1936–1939) in Biscay (Basque Country), this study examines its legacy on voting behavior (1983–2015). Results indicate that fascist airstrikes increased Basque nationalism while selective violence diminished the popularity of Basque parties. Individual and community-level evidence suggests that airstrikes fostered the intergenerational transmission of political attitudes. Violence can boost national identities, but it can also erode them: it depends on the type.