Publication Type: ProceedingAbstract: Frustrated with the failure of more orthodox strategies to stem the risk of mass destruction terrorism, particularly with nuclear weapons, analysts have begun to advocate threatening deterrent retaliation against states whose insecure mass destruction weapons and materials are stolen and used in terrorist attacks against the United States. After elaborating on what is here termed deterrence of negligence, the paper evaluates a narrowly defined question: what would be the effect of the United States enunciating, either publicly or through private channels, a deterrence of negligence policy? This question is addressed in three parts. First, the status of current unilateral and cooperative efforts to secure vulnerable nuclear materials and weapons in the two case countries, Russia and Pakistan, is detailed. Second, the contribution of a deterrence of negligence policy towards preventing a terrorist attack with mass destruction weapons prior to such an attack is assessed. Third, the contribution of the policy towards making follow-on attacks less likely in the aftermath of an initial attack is assessed. Finally, in the context of a skeptical assessment of deterrence of negligences ability to ameliorate the threat of mass destruction terrorism, the paper briefly considers potential alternative strategies that could either complement or substitute for it.