New data reveals that comprehensive peace agreements (CPAs) signed since 1989 significantly extend peace durations. This study argues implementation acts as a powerful peace-building mechanism by normalizing relations between signatory groups and solving commitment problems. The research shows CPA implementation not only stabilizes relationships among negotiators but also reduces conflict behavior for non-signatory actors.

Data & Methods: Analysis of 1989–present CPAs using statistical tests demonstrates systematic causal effects.

Key Finding: Extent of agreement implementation strongly predicts longer-lasting peace across all involved groups, including non-participants.

Implication: These results suggest that successful implementation is the critical phase in post-conflict transitions.