The Road to Hell? Third-Party Intervention to Prevent Atrocities


  • Earlier drafts of this article were presented at the University of Virginia, the Elliott School of International Affairs, the International Relations Workshop at the University of Wisconsin, Madison, and the 2010 meetings of the American Political Science Association. We would like to thank Brittany Boudens, Holger Schmidt, Charles Glaser, Jim Goldgeier, Harris Mylonas, Jim Lebovic, and Elizabeth Saunders for helpful comments on these occasions and also the anonymous reviewers at AJPS. Scott Straus’ research was supported with a grant from the United States Institute of Peace.


Preventing large-scale atrocities has emerged as an important policy goal of the post–Cold War period. However, a debate exists about the effects of creating an international institution to prevent atrocities. Advocates of intervention argue that a credible threat to intervene should deter perpetrators and stop atrocities when deterrence fails. Critics argue that third-party intervention, by strengthening weak minority groups and lowering the cost of war, encourages rebellions and so makes war and atrocities more likely. We develop a model of intervention to analyze this debate. The model shows that the negative effects of intervention highlighted by critics can be mitigated if the third party is relatively neutral and if alternative costs are imposed on decision makers. We conclude that with appropriate institutional design, the net impact of stronger third-party commitments to end atrocities will be to lower the expected level of atrocities.