The main aim of this paper is to contribute to the literature on ontological security by empirically investigating how the European Union (EU), which is perceived as one of the most important actors that provides means and/ or grounds for overcoming antagonisms through transformation of the ‘Self-Other’ dialectics, fails to become an agent of peace. Drawing on the case of Republika Srpska (RS), a political entity in Bosnia and Herzegovina (BiH), we aim to understand how the EU’s post-conflict stabilization efforts, which, among others, presuppose the de-intensification of the antagonistic identity narratives, become entrapped in ethnopolitical narratives, and even ‘ethnicized’ by the ethnopolitical elite in RS. To answer these questions, we analyzed news articles at two critical junctures, namely the negotiations on the Stabilisation and Association Agreement (2005–2007) and the Butmir Process (2009), two of the most important EU-driven initiatives in post-conflict BiH. We find that those initiatives, which promised to make BiH more functional and stable, challenged the existing ethnopolitical narratives in BiH, particularly on the side of the ethnopolitical elite in RS.