Since the end of the Cold War, international third parties such as the United Nations (UN) have become frequent guarantors of peace agreements. Existing studies document that third parties provide assurances that help maintain peace, yet these studies nearly exclusively marshal evidence at the macro-level and focus on elites rather than foot soldiers. Also, their focus is often on the immediate aftermath of war, rather than how third parties affect agreement implementation. Using a novel phone survey of 4,435 ex-combatants from the FARC-EP, Colombia's largest rebel group, and an embedded survey experiment, we examine the role of third parties in providing guarantees to foot soldiers during the implementation of the Colombian peace agreement, five years after its signing. We find no evidence that the UN Verification Mission in Colombia increased: confidence among ex-combatants that the government would fulfill its commitment to implement the peace agreement, confidence that the FARC would do the same, perceptions of physical safety, positive perceptions of ex-combatants' future economic prospects, nor trust in institutions more generally. We discuss possible explanations for these null findings and the study¿s relevance to debates about conflict termination, peace agreement implementation, and international intervention.
