A Hierarchy of Aggression: Gradations of Inter-Democratic Hostility

• In Event: Key Concepts in International Security

Abstract

How broad are the contours of the democratic peace? Scholars have found that democracies almost never engage in interstate wars with one another. However, democracies do initiate conflicts short of war with other elected regimes, for example, by introducing economic sanctions or supporting rebels fighting other democracies. We propose the existence of a “hierarchy of aggression,” in which the constraining effects of democracy condition the hostile behavior of states with electoral regimes in patterned and predictable ways. Specifically, we contend that the pacifying effects of institutions and norms on relations between democracies operate more powerfully as behaviors become more militarized, more violent, and more overt. Therefore, inter-democratic conflict becomes progressively less likely as states move up the hierarchy of aggression: economic sanctions and trade wars, low-level militarized interstate disputes, covert regime change, support for foreign rebels, high-level militarized interstate disputes, and interstate war. Using data on these various forms of interstate dispute and conflict, we test this claim through the systematic assessment of inter-democratic relations since 1945. Our argument has significant implications for understanding the scope, power, and limits of one of the most prominent theories in IR scholarship—the democratic peace theory. It is the first paper to consider the full range of conflict behaviors between democratic states. The project also sheds new light on interstate bargaining and crisis dynamics as well as the use of force in the international arena.

Authors

• Dominic Tierney, Swarthmore College

• Ryan D. Grauer, University of Pittsburgh

• Luke N. Condra, University of Pittsburgh