Distinguishing rivals that go to war from those that do not: A quantitative comparative case study of the two paths to war

Many interstate enduring rivalries experience wars, some do not. This analysis presents and tests an explanation of whether, why, and how rivals go to war. It is argued that rivalries between equal states that do not go to war are those in which territorial issues are not at stake. Rivalries in the absence of territorial issues tend to go to war only by being embroiled in an ongoing war by a third party. A series of tests with emphasis on rivalries between major states occurring during 1816-1986 supports the territorial explanation. Two distinct paths to war are empirically identified-one leading to a dyadic war involving a territorial dispute(s) and a second path by which rivals without a territorial dispute join an ongoing war because of contagion factors.