Uploaded January 2026 | Updated September 2026, 2 days ago
Speaker: Jeffrey Knopf
Because no nuclear weapon has been used to attack a target since 1945, a tendency to project existing trends into the future could lead people to expect this pattern of nuclear nonuse to continue. But is it possible to have confidence about whether and how far into the future the record of nonuse will continue? In this talk, Dr. Knopf will argue that confidence about avoiding nuclear use is not possible because the probability of a nuclear attack or nuclear exchange cannot be predicted. This unpredictability reflects the nature of strategy and the available evidence about nuclear deterrence. Strategy involves making a prediction that a chosen course of action will lead to outcomes desired by a state. But attempts to make forecasts about nuclear deterrence are beset by uncertainty and trade-offs and by the interaction of those two problems. Using a thought experiment to illustrate, Dr. Knopf will suggest that the problems of uncertainty and trade-offs make it impossible to reliably estimate the likelihood that any given nuclear strategy will prevent nuclear-weapons use. If this analysis is correct, it should motivate greater efforts to reduce the chance of nuclear-weapons use and to find alternatives to nuclear deterrence. Steps that could help advance those objectives include measures to strengthen inhibitions against nuclear use, as well as renewed efforts to move toward nuclear disarmament.
Speaker: Jeffrey Knopf
Because no nuclear weapon has been used to attack a target since 1945, a tendency to project existing trends into the future could lead people to expect this pattern of nuclear nonuse to continue. But is it possible to have confidence about whether and how far into the future the record of nonuse will continue? In this talk, Dr. Knopf will argue that confidence about avoiding nuclear use is not possible because the probability of a nuclear attack or nuclear exchange cannot be predicted. This unpredictability reflects the nature of strategy and the available evidence about nuclear deterrence. Strategy involves making a prediction that a chosen course of action will lead to outcomes desired by a state. But attempts to make forecasts about nuclear deterrence are beset by uncertainty and trade-offs and by the interaction of those two problems. Using a thought experiment to illustrate, Dr. Knopf will suggest that the problems of uncertainty and trade-offs make it impossible to reliably estimate the likelihood that any given nuclear strategy will prevent nuclear-weapons use. If this analysis is correct, it should motivate greater efforts to reduce the chance of nuclear-weapons use and to find alternatives to nuclear deterrence. Steps that could help advance those objectives include measures to strengthen inhibitions against nuclear use, as well as renewed efforts to move toward nuclear disarmament.
