Strategic Militarization, Deterrence and Wars∗ Matthew O. Jackson† and Massimo Morelli‡ Revised: October 2009 Forthcoming in the Quarterly Journal of Political Science Abstract We study countries choosing armament levels and then whether or not to go to war. We show that if the costs of war are not overly high or low, then all equilibria must involve dove, hawk, and deterrent strategies and the probability of war is positive (but less than one) in any given period. Wars are between countries with differing armament levels and the frequency of wars is tempered by the presence of armament levels that are expressly chosen for their deterrent properties. As the probability of winning a war becomes more reactive to in- creased armament, the frequency of wars decreases. As it becomes increasingly possible to negotiate a credible settlement, the probability of peace increases, but the variance of armament levels increases and war becomes increasingly likely when negotiations break down. Keywords: Deterrence, War and Peace, Militarization, Hawks, Deterrents and Doves. ∗We thank various seminar participants, as well as Sandeep Baliga, Ken Binmore, Alexandre Debs, Jim Fearon, and Tomas Sj¨ostr¨omfor helpful conversations. We also thank Jon Eguia for extensive comments on an earlier draft. †Department of Economics, Stanford University, Stanford, California 94305, USA. Email: jack-
[email protected], http://www.stanford.edu/∼jacksonm ‡Dept. of Political Science and Dept. of Economics, Columbia University, 720 IAB, 420 W. 118th street, New York NY 10027;
[email protected]; http://www.columbia.edu/cu/polisci/fac- bios/morelli/faculty.html 1 When crises arise, hawks counsel resolve, and the implementation of steps to make the deterrent threat credible.