The crisis bargaining incentives discussed in Chapters 1 and 2 seem unlikely, by themselves, to explain the intensity of the late Cold War nuclear competition, or the failure of arms control to ameliorate it. The nuclear balance was delicate – not fragile. Why would the superpowers pay such high costs, and potentially court dangerous political spirals that risked crisis and war, just for the long shot benefit of escaping stalemate or preventing their adversary from doing so? Theoretically, technological or perceptual uncertainties about nuclear stalemate could be consistent with either minimal or severe military competition. Arms control that regulates the technical and perceptual environment might be feasible, and much less costly, than competitive alternatives. Some general account is needed that explains how states will choose a mix of competitive and cooperative nuclear policies, and thus the degree and type of nuclear competition that ensues.