The origins and war proneness of interstate rivalries

The study of interstate rivalry, which has made major contributions to theory and research on war, is reviewed, and new research on the role of territory in the origin and war proneness of rivalries is presented. Recent research has shown that states that are rivals are much more likely to go to war than are other states, and that about half the wars fought since 1815 have involved states that are rivals. This review describes the origins of interstate rivalries in terms of whether they begin over territorial disputes, policy disputes, or disputes over the nature of a state's regime. It finds that states that dispute territory have a greater probability of becoming rivals than expected by chance, compared with states that dispute other issues. It also investigates the extent to which territorial disputes and the recurring of disputes, despite their content, are related to the onset of war.