Geography and weapons technology form an important context in which interstate, intrastate, and extra-state conflicts occur. In this chapter we explore how geography and weapons technology affect the territory controlled by armed rivals and the risk of violence between them. We begin with Boulding's (1962) spatial model of intergroup rivalry, which highlights geographical and technological dimensions of conflict such as spheres of influence, offensive and defensive technologies, and strategic depth. We then summarize O'Sullivan's (1991) three-dimensional extension of Boulding's model. We turn to the Lanchester (1916) model of war attrition to illustrate how combinations of geography and weapons technologies create incentives for nations or groups to go on the offensive, or stay on the defensive, in violent encounters. We also present Alesina and Spolaore's (2003) theory of the number and size of nations in the international system. Selected empirical studies related to the geography and technology of conflict are summarized.

Boulding's Model of Spatial Conflict

Basic Model

In his classic work Conflict and Defense: A General Theory, Boulding (1962) modeled conflict over territory among states or non-state groups by adapting prior economic theory on spatial competition. The basic model is shown in Figure 9.1, where two players A and B have home bases located at points A and B in a geographic space represented by line L1L2. A player's home base might be its capital if the player is a state, or a jungle or mountainous hideout if the player is a rebel or terrorist organization.