Abstract: | Nuclear proliferation, lax security standards in the storage of fissile materials, and international apathy in the prosecution of terrorists make nuclear terror a serious threat to the United States and its allies, yet no doctrine of retaliation has been established. To decrease the probability of terrorist use of nuclear weapons, a doctrine of retaliation—a negligence doctrine—should be considered. If the United States can distinguish whose fissile material was used for a nuclear terror event, a negligence doctrine would prescribe retaliation against that state. Where the proximate cause—terrorists—is unavailable for deterrent retaliation, deterring an accessible mediate cause—a state that has failed to adequately secure its fissile material—is one of a few effective alternatives. In the absence of such a negligence doctrine, the United States and its allies are increasingly vulnerable to a nuclear terror attack and the ensuing negative consequences. |