Fear, Appeasement, and the Effectiveness of Deterrence1 Ron Gurantz2 and Alexander V. Hirsch3 June 26, 2015 1We thank Robert Trager, Barry O'Neill, Tiberiu Dragu, Kristopher Ramsay, Robert Powell, Doug Arnold, Mattias Polborn, participants of the UCLA International Relations Reading Group, Princeton Q-APS Interna- tional Relations Conference, and Cowbell working group, and two anonymous reviewers for helpful comments and advice. 2Corresponding Author. University of California, Los Angeles. Department of Political Science, 4289 Bunche Hall, Los Angeles, CA 90095-1472. Phone: (310) 825-4331. Email:
[email protected]. 3Associate Professor of Political Science, Division of the Humanities and Social Sciences, California Insti- tute of Technology, MC 228-77, Pasadena, CA 91125. Email:
[email protected]. Abstract Governments often fear the future intentions of their adversaries. In this paper we show how this fear can make deterrent threats credible under seemingly incredible circumstances. We consider a model in which a defender seeks to deter a transgression with both intrinsic and military value. We examine how the defender's fear of the challenger's future belligerence affects his willingness to respond to the transgression with war. We derive conditions under which even a very minor transgression effectively \tests" for the challenger's future belligerence, which makes the defender's deterrent threat credible even when the transgression is objectively minor and the challenger is ex- ante unlikely to be belligerent. We also show that fear can actually benefit the defender by allowing her to credibly deter. We show the robustness of our results to a variety of extensions, and apply the model to analyze the Turkish Straits Crisis of 1946.