How Wars End starts with Carl von Clausewitz’s famous insight that war is politics by other means. War is not just an exercise in martial engineering, two waves of soldiers and war machines crashing against each other. Rather, war is a fundamentally political act. States start wars to accomplish political goals.But, a state will only use the tool of war to accomplish political goals if the costs of fighting do not exceed the expected gains, and if the state is confident that it can accomplish its goals. As the costs of war escalate and its confidence in winning declines, a belligerent will try to end its war.There’s a big catch to the idea that rising costs and declining prospects of victory will push a state to end a war. That portrayal assumes that belligerents are confident that once war ends, each side can return to peace. Sometimes, a belligerent doesn’t trust its adversary to abide by a war-ending peace settlement. The belligerent fears that the adversary might bide its time after peace is struck and launch a surprise attack when the opportunity presents itself. A belligerent fears an adversary who will pose this kind of long term threat to its security. Under these circumstances, belligerents may ignore the costs of war and doubts about ultimate victory, and instead pursue the decisive defeat and unconditional surrender of the adversary. Accomplishing this kind of total victory allows the belligerent to annex the adversary, occupy its territory, and/or impose regime change. Doing so solves the distrust problem, as the adversary wouldn’t be able to break a war-ending peace agreement.So this book provides a general explanation of how wars end. It is also the first book to answer the big historical question: When do belligerents agree to end a war before one side has been completely defeated, and when do belligerents try to achieve absolute victory and inflict unconditional surrender?