Abstract Police reform demonstrated the fragility of the transition process in Bosnia and the limitations of the prospect of European Union membership. To the two mechanisms of conditionality and socialization commonly mentioned in the Europeanization literature, this article adds a third – external imposition – which is specific to the case of Bosnia. The fact that the High Representative resorted to coercive measures in order to implement European conditions needs to be accounted for in any explanation of Bosnia's Europeanization. In the case of police restructuring, conditionality was monopolized by the High Representative and socialization did not take place because the reforms were not perceived as legitimate by at least one of the parties. Domestic factors, including the complex governance system introduced by the Dayton Agreement and recalcitrant nationalist elites, also hindered the Europeanization process in Bosnia.