Abstract Although United Nations peace missions have played an important conflict management role for decades, a backlash against the post-Cold War model of ‘liberal peacebuilding’ and other recent developments have called their future into doubt. Some observers contend that a ‘pragmatic turn’ is now underway—a shift away from ambitious plans to transform war-torn societies into liberal democracies and towards more modest and realistic goals. Whether ‘pragmatism’ offers a viable alternative framework for peacebuilding, however, is less clear. This article challenges key assumptions of the pragmatic approach to peacebuilding, including the notion that UN missions can be ‘agnostic’ about the governance arrangements of societies that host these operations, as some proponents of pragmatism recommend. Historical case-studies show that such assumptions are integral features of collective conflict management systems, including UN peace missions. Moreover, a close examination of the pragmatist approach reveals that it, too, is based on such assumptions—namely, that building peace requires the promotion of pluralist societies and states. Pluralist peacebuilding, the article concludes, could offer a compelling foundation for future UN missions in an era of rising statist–authoritarianism, but developing this approach will first require discarding pragmatism's pretence of ideological agnosticism.