War is in the error term

Deductively consistent, rationalist explanations for war generally imply that the onset of war is unpredictable and that theories of war are indeterminate. James Fearon shows that a rationalist explanation for war most often suggests that states resort to force because of factors that cannot be observed by the states involved. For states, it follows, war must appear as a random event. By implication, factors that cannot be observed by states typically cannot be observed by analysts. If analysts can distinguish states that are willing and able to fight from those that are not, even ex post, then states will be able to distinguish among such states as well, ex post, and will internalize this information in their decisions. To observers, then, the causes of war must always be in the "error term.'' I discuss the argument, its relationship to the literature, and implications for applied and theoretical research.