In the Nick of Time: Conflict Management, Mediation Timing, and the Duration of Interstate Disputes Patrick M. Regan Binghamton University (SUNY) and Allan C. Stam Yale University This paper develops a theoretical argument linking time and the timing of conflict management efforts to dispute duration. We test competing hypotheses on conflict data drawn from disputes in the post-1945 period. Our analysis demonstrates that the effects of mediation vary substan- tially over the course of a dispute. Specifically, we note that mediation has a curvilinear relationship with time and the ending of disputes. Mediation efforts that occur soon after disputes begin have the best chance of reducing expected future dispute duration. Following this initial period, subsequent mediation efforts lead to longer rather than shorter disputes. After a long period, mediation again leads to shorter rather than longer disputes. We also find that there should be consis- tency in the mediators used to manage a conflict rather than shifting personnel to interject new ideas. What is the effect of mediation on the duration of interstate disputes? Does the timing of a particular mediation attempt influence the overall duration of the dispute? These seemingly straightforward questions have proven remarkably resis- tant to systematic investigation. While all disputes between interstate actors even- tually end, understanding how and when occupies a substantial part of the study of international relations. Most would agree that the likelihood of any single mediation attempt ending a dispute depends, in part, on the duration of the dispute and the timing of mediation. In order to be effective, mediation must take place at a propitious moment. Unfortunately, there is little agreement as to when that precise moment might actually occur. Bercovitch has argued, for example, that mediation would have its greatest effect at some middle point in a conflict: “Mediation, it seems, is more effective when it follows, rather than precedes, some ‘test of strength’ between parties. The point in time following either some minimum duration ~here defined as 12–36 months! , a stalemate, or mutual exhaustion seems to be the ideal phase in the dispute to initiate mediation. Protracted and intense international disputes Authors’ note: We would like to thank Jacob Bercovitch for providing us with the data used in the analysis, and three anonymous reviewers for their comments on the manuscript. International Studies Quarterly ~2000! 44, 239–260. © 2000 International Studies Association. Published by Blackwell Publishers, 350 Main Street, Malden, MA 02148, USA, and 108 Cowley Road, Oxford OX4 1JF, UK.