Since time immemorial states have engaged in warfare to assert their rights. In contemporary society it is common to ask why wars occur, the historical record indicates that a more appropriate question is why they occur so rarely. This paper argues that warfare is, as Clausewitz, argued an extension of politics, and that it is an activity that states' engage in when they perceive that the benefits will outweigh the costs. 10 pgs. Bibliography lists 10 sources.