Foundations for integrating the democratic and territorial peace arguments

The democratic and territorial peace arguments explain interstate peace via distinct mechanisms. Yet they can be integrated. I theoretically derive both the unique domains in which each argument might operate and the ways in which the two arguments might reinforce one another. An analysis of the period 1816-2001 demonstrates support for a more integrative approach. Within contiguous dyads, border settlement significantly reduces conflict, even for non-democratic dyads. Democratic dyads, however, experience no such effect in the absence of border settlement. Nonetheless, the democratic peace functions strongly in non-contiguous dyads, and even the most peaceful, contiguous dyads require both democracy and border settlement. Such findings offer a foundation for further theoretical development that integrates the two arguments.