Political Institutions and War Initiation: The Democratic Peace Hypothesis Revisited†

Abstract. This chapter analyzes the influence of democratic institutions—specifically, the effects of (i) electoral uncertainty when individuals within a nation have different preferences over public peaceful investment and (ii) greater checks and balances that lead to a more effective mobilization of resources for both public peaceful investment and arming—on a nation’s incentive to arm and willingness to initiate war. The analysis is based on a model where nations contest some given resource and where they cannot commit to their future allocations to arming; yet, the victor in a conflict today gains an advantage in future conflict and thus realizes a savings in future arming. These assumptions imply that, despite the short-term incentives to settle peacefully, one or both nations might choose to initiate war. In such a setting, electoral uncertainty tends to make a democracy more peaceful relative to an autocracy, whereas greater checks and balances tend to make a democracy less peaceful. Thus, while two democracies might be more peaceful than two autocracies when paired against each other in a contest over a given resource, this is not necessarily the case. Even under conditions where democracies are most likely to be peaceful with one another, democracies are at least as likely to be in war with autocracies as autocracies are likely to be in war each other