What's stopping you? The sources of political constraints on international conflict behavior in parliamentary democracies

Much of the work on the democratic peace treats democracies as a homogenous set. In this paper we focus on the heterogeneity of established parliamentary democracies and investigate the effects of their domestic constraints on international conflict behavior. We emphasize leaders' vulnerability to removal from office and how this vulnerability varies across democracies as a function of two aspects of a ruling parliamentary coalition: 1) its political position, that is, whether a government is "right" or "left"; and 2) its structural complexity. We present a model of the relationship between levels of conflict and leaders' vulnerability to removal from office. The model concludes that leaders who are more likely to be removed from office, should they use force, arc less likely to become involved in militarized interstate conflict; but that once involved, they are more likely to see their conflicts escalate. We find that right governments (whose leaders are less vulnerable to removal from office should they use force) are more likely to be involved in militarized disputes, while left governments (whose leaders are more likely to be removed from office should they use force) are more likely to see the disputes in which they are involved escalate. Our evidence indicates that structural complexity is largely unrelated to the likelihood of either involvement in or escalation of militarized interstate disputes.