Explaining Decisiveness in War

In theories that model war as a bargaining problem, fighting during war plays a key role in leading to a convergence of beliefs about the relative power of each side and the end of a war. But such models disagree about precisely how wartime experiences are informative and say little about how these beliefs persist after the war ends. In this dissertation, I argue that different types of experiences with fighting during a war shape long-term beliefs about the relative power of each side. More direct experiences that affect a larger number of individual actors and are consistent over a longer period of time should be more likely to shift such beliefs than experiences that are indirect, inconsistent, or short-lived. Changes in these beliefs determine the degree to which a war\u27s outcome is more or less decisive and thus the likelihood of the war recurring. Across a variety of cases and using multiple methods, I find general support for my expectations. Using a new dataset compiled from electoral, demographic, and military sources, I show that areas in France that were invaded by Germany during the Franco-Prussian War were significantly less likely to support a revanchist political organization and more likely to vote for a more conciliatory political party after the war. I supplement that finding with primary source evidence to detail how the personal experiences of individual French leaders during the war affected their foreign policy after the war, with more direct experiences leading to more conciliatory attitudes towards Germany. To show further evidence of how direct experiences change beliefs at the individual level, I make use of two nationally representative surveys conducted before and after the 2008 Russo-Georgian War in Georgia. I find that respondents in regions of Georgia invaded by Russia had a lower desire to invest resources into challenging Russia militarily compared to respondents in non-invaded regions. A final set of historical cases provides additional supporting evidence from the World Wars, the Egyptian-Israeli Wars, and the Gulf Wars. Though the existing understanding of decisiveness in war tends to view shorter wars with one-sided battles as most decisive, the theory and evidence presented in this dissertation instead show that longer wars that affect a greater number of individuals directly are most likely to prove decisive