| In most wars between countries, political settlements allow for a quick end to fighting, yet occasionally fighting endures for years, sometimes at extraordinarily high cost. What explains these long, costly wars? Why do war participants sometimes refuse to reach a political agreement despite the horrendous costs of extended fighting? I address this question from the perspective of the bargaining model of war, focusing in particular on three mechanisms that are all capable of explaining a decision to fight. In the first mechanism, leaders with divergent expectations go to war both expecting to win; in these cases, I argue that events within war help to correct pre-war misconceptions and thus set the stage for a negotiated agreement. This process generally occurs quickly, with the consequence that this mechanism, although responsible for most wars that we observe, cannot explain the particularly big conflicts. The second mechanism involves domestic politics, with leaders pursuing policies that are not in the national interest. Here I argue that as wars become more intense leaders are increasingly constrained in their ability to extend fighting unnecessarily. As a result, this mechanism can account for long wars, but only when they are fought at a relatively low level of intensity. Thus, only the third mechanism---commitment problems associated with shifting power, in which declining powers seek a significant victory that will forestall their decline---can account for wars that are both long and intense. Moreover, in some commitment problem wars, the declining power's opponent interprets the declining power's behavior as indicative of dispositional aggressiveness, with the implication that enduring peace will require a fundamental revision of the declining power's regime; it is this dynamic that leads to the rare but extremely important phenomenon of sincere demands for unconditional surrender. I test specific propositions arising out of the theory both quantitatively, in statistical analyses of war duration and severity, and qualitatively, in case studies of World War II in Europe and of the lesser-known Anglo-Persian, Franco-Turkish, and Paraguayan Wars. |
