War as a Commitment Problem

Although formal work on war generally sees war as a kind of bargaining breakdown resulting from asymmetric information, bargaining indivisibilities, or commitment problems, most analyses have focused on informational issues. But informational explanations and the models underlying them have at least two major limitations: they often provide a poor account of prolonged conflict, and they give an odd reading of the history of some cases. This article describes these limitations and argues that bargaining indivisibilities should really be seen as commitment problems. The present analysis then shows that a common mechanism links three important kinds of commitment problem: (1) preventive war, (2) preemptive attacks arising from first-strike or offensive advantages, and (3) conflicts resulting from bargaining over issues that affect future bargaining power. In each case, large, rapid shifts in the distribution of power can lead to war. Finally, the analysis elaborates a distinctly different mechanism based on a comparison of the cost of deterring an attack on the status quo with the expected cost of trying to eliminate the threat to the status quo.For helpful comments and criticisms, I thank James Fearon, Hein Goemans, Lisa Martin, Sebastian Mazzuca, Branislav Slantchev, and seminar participants at the University of Montreal–McGill Research Group in International Security, the Institute in Mathematical Behavioral Sciences, University of California, Irvine, and University of California, Santa Barbara. I also gratefully acknowledge the support of the National Science Foundation (SES-0315037).