What drives soldiers to risk their life in combat? We show that the legacy of war creates lasting conditions that encourage younger generations to take greater risks when fighting for their country. Using individual-level data from over 4 million British war records, we show that WWI deaths deeply affected local communities and the behaviour of the next generation of soldiers. Servicemen from localities that suffered heavier losses in WWI were more likely to die or to be awarded military honours for bravery in WW2. To explain these findings, we document that WWI deaths promoted civic capital in the inter-war period -- as demonstrated by the creation of lasting war memorials, veterans‘ associations and charities, and increased voter participation. In addition, we show that sons of soldiers killed in WWI were more likely to die in combat, suggesting that both community-level and family-level transmission of values were important in this context.