This article challenges the idea that women are necessarily more peaceful than men by looking at examples of female combatants in ethno-nationalist military organizations in Sri Lanka and Northern Ireland. Anti-state, ‘liberatory’ nationalisms often provide more space (ideologically and practically) for women to participate as combatants than do institutionalized state or pro-state nationalisms, and this can be seen in the cases of the LTTE in Sri Lanka and the IRA in Northern Ireland when contrasted with loyalist paramilitaries in Northern Ireland. However, the role of the female combatant is ambiguous and indicates a tension between different conceptualizations of societal security, where female combatants both fight against societal insecurity posed by the state and contribute to internal societal insecurity within their ethno-national groups.