The study’s aims are to analyze the endorsement of the ethos of conflict (EoC )narrative in the Serbian-Albanian conflict among the adults in Serbia, its relation to political conservatism, and its role in pushing conservative political action. A total of N = 1613 adults (aged 18+) were recruited for face-to-face interviewing, in a representative sampling procedure, in December 2019 in Serbia. The results show high endorsement of EoC in the Serbian-Albanian fray; the mediation effect of EoC (having both high EoC and high conservatism is associated with greater political activism); the relation between EoC and political activism is moderated by age (the older population endorsing higher EoC was more politically active). In the future, we should address more actively the mobilizers of reactionary political actions in public and individual spheres, to better understand the mechanisms for achieving long-term peace.