Explaining rivalry escalation to war: Space, position, and contiguity in the major power subsystem

Abstract

Vasquez's (1996) rivalry escalation theory stressed territorial disputes as the principal focus for a two-path explanation of war. Neighbors fight over adjacent space and non-neighbors sometimes join ongoing wars between neighbors. But major powers are also much concerned with positional issues. Expanding the war motivation focus to encompass both spatial and positional issues facilitates the development of a new, more elaborate theory from which several new hypotheses can be derived, in addition to the older ones. Testing of the new theory can also proceed with rivalry data not based on dispute density measures, different types of contiguity can be assessed, and the presence of spatial-positional issues can be measured directly, as opposed to relying on a proximity proxy. The empirical outcome strongly supports the two-path, two-issue theory. In the major power subsystem, noncontiguous rivals outnumber contiguous rivals, dyadic wars are scarce, and war joining has been the norm. Spatial issues alone would have a hard time accounting for this pattern. Variable mixes of spatial and positional issues are able to account for it and a number of derived hypotheses reasonably well. This is not the last word on rivalry escalation to war but it appears to be an additional step in the right direction.