Why does fighting recur after some civil conflicts, whereas peace consolidates following others? The untested conventional wisdom is that—absent safeguards—postwar elections are dangerous for peace because electoral losers will reject the election results and remilitarize. New cross-national data on postwar election results and belligerent-level data on remilitarization contest this view. Citizens tend to elect peace because they engage in “security voting”; they elect the party that they deem best able to secure the state, using the war outcome as the heuristic that guides their security vote. Findings indicate that the chance of renewed war increases if there is an inversion in the military balance of power after war, and the war-loser performs poorly in the elections. If, instead, relative military power remains stable, or citizens accurately update their understandings of the postwar power balance, a civil war actor is unlikely to remilitarize if it loses the election. Knowing when and how these belligerent electoral actors choose to either sustain or break the peace informs important theoretical and policy debates on how to harness democracy's benefits while mitigating its risks.