This article proposes that wars are fought to monitor one another’s reductions of overinvestment in broadly-defined military preparedness. If two potential combatants are overinvested in military preparedness, it is in their individual interest to scale down in order to use their resources in politically more desirable ways. However, unilateral disarmament exposes one to the risk of attack or extortion by the other. To political leaders, overinvestment in military preparedness is in effect a bad which wars get rid of. Wars can therefore be a politically desirable way of monitoring the other side’s disarmament. The analysis explains why the frequency of warfare increases in poverty, and offers a number of additional implications
