Neta C. Crawford
‘Background ideas’ are the essential foundation for decision-making, action, and institutionalized practices. These ideas are sometimes explicitly articulated—when defended or asserted in new contexts—but more often simply assumed and unstated. Decision-makers often believe that war works—that it is effective—and moreover that war can achieve objectives at comparatively low cost. Jus ad bellum and jus in bello considerations in the just war tradition—including last resort, necessity, probability of success, and proportionality, and the idea of double effect—are also explicitly concerned with utility—whether and when war works. Utility is also an essential element in the discourse about military necessity. Does war work? What is it good for? Why does it tend to extremes of violence? What are its costs? How do decision-makers hold onto beliefs about the utility of war in the face of disconfirming evidence?