A Unified Theory and Test of Extended Immediate Deterrence

We present a unified theory and test of extended immediate deterrence—unified in the sense that we employ our theoretical deterrence model as our statistical model in the empirical analysis. The theoretical model is a straightforward formalization of the deterrence logic in Huth (1988) and Huth and Russett (1984) , coupled with private information concerning utilities. Our statistical analysis suggests that the attacker and defender's decisions are influenced by the balance of forces, nuclear weapons, defender-protege military alliances, arms transfers, and trade, as well as the regime types of those involved. Many of these findings contradict previous research by Huth (1988) and Huth and Russett (1988) . We find that many of the variables involved in the deterrence calculus are nonmonotonically linked to the probability of deterrence success or war. We illustrate the results with case studies of the Soviet-Japanese dispute over Manchukuo (1937–1938) and the Berlin Blockade (1948).     

Public Commitment in Crisis Bargaining

The "audience cost" literature argues that highly-resolved leaders can use public threats to credibly signal their resolve in incomplete-information crisis bargaining, thereby overcoming informational asymmetries that lead to war. If democracies are better able to generate audience costs, then audience costs help explain the democratic peace. We use a game-theoretic model to show how public commitments can be used coercively as a source of bargaining leverage, even in a complete-information setting in which they have no signaling role. When both sides use public commitments for bargaining leverage, war becomes an equilibrium outcome. The results provide a rationale for secret negotiations as well as hypotheses about when leaders will claim that the disputed good is indivisible, recognized as a rationalist explanation for war. Claims of indivisibility may just be bargaining tactics to get the other side to make big concessions, and compromise is still possible in equilibrium.     

Mutual Optimism as a Rationalist Explanation of War

Blainey (1988) argued that crises are more likely to end in war when two nations disagree about their relative power. Fey and Ramsay (2007) claim that this widely used “mutual optimism” explanation is theoretically incoherent. Their criticism neglects the need to specify a behavioral causal mechanism that links beliefs to the outbreak of war. We show how the rationalist game‐theoretic work on the causes of war provides such mechanisms—the risk‐return trade‐off and costly signaling—and demonstrate that these models are immune to Fey and Ramsay's critiques. We also show that the class of models Fey and Ramsay propose make the substantively unwarranted assumption that an actor can unilaterally impose peace on an opponent who strictly prefers war. Their finding that war does not occur in equilibrium has nothing to do with mutual optimism. We conclude that the mutual optimism explanation can be grounded on firm rationalist foundations.