The MAD Heuristic and the Nuclear Revolution

How, why, and when nuclear deterrence works remains a puzzle. This article argues that a new theory, nuclear heuristics theory, explains the evidence better than existing explanations. An application of poliheuristic decision theory, nuclear heuristics theory posits that the main factor explaining the success of nuclear deterrence is the mutually assured destruction (MAD) heuristic, a decision-making shortcut that assumes that any nuclear war means MAD, even when capabilities fall short of the assured destruction level. Implications of the theory include the expectation that decision-makers never seriously consider nuclear preemption in a crisis, that the conventional military balance is important in determining the outcome of nuclear crises, and that the nuclear balance is not. This theory is tested against two existing theories, nuclear revolution theory and nuclear superiority theory. Evidence comes from a survey of the existing literature and a process-tracing analysis of US decision-making during the Cuban Missile Crisis based on transcripts of tape-recorded deliberations of President Kennedy's advisory executive committee. The evidence strongly supports nuclear heuristics theory: Leaders do speak and act in accordance with the MAD heuristic. Nuclear superiority theory is badly undermined.