Power is the fundamental determinant of international outcomes. It determines who getswhat and at what cost, who is most likely to win a war, and what decisions are adoptedin international negotiations. As such, it is often an object of strategic behavior itself. Forexample, states negotiate over their armament; they fight to increase their future strength;and they sometimes pretend to be stronger than they actually are. This book is aboutpower, its value, and when and why its pursuit leads to war. Using bargaining modelsin which power—the ability to hurt or to offer rewards—is endogenous, I analyze states’strategies toward power. When do they fight to increase it? When, on the contrary, dothey tame it down to alleviate the fears of their neighbors and avoid war? How do theymisrepresent their strength? And how do they allocate their scarce means of coercion atdifferent fronts?