Deterring the Smuggling of Nuclear Weapons in Container Freight Through Detection and Retaliation

TLDR

Concerns that terrorists could smuggle nuclear bombs via container freight have prompted calls for 100 % inspection, yet some scenarios suggest partial inspection might suffice to deter such attempts. The study quantifies a game‑theoretic model of terrorist decision making using publicly available data to assess how nuclear detection technologies influence deterrence. Using publicly available data, the authors construct a game‑theoretic model of terrorist decision making to evaluate the impact of nuclear detection technologies on deterrence. The analysis shows that without credible high retaliation costs, 100 % inspection is required, but if the defender can credibly threaten costly retaliation, partial inspection can deter smuggling, and these results are robust, indicating that diplomatic stance on retaliation is as crucial as the inspection rate.

Abstract

Concerns about terrorists smuggling nuclear bombs into the United States in container freight have led to demands for 100% inspection at either U.S. or foreign ports. However, under some circumstances, it may be possible to deter nuclear smuggling attempts with less than 100% inspection. Based on publicly available data, we quantify a game-theoretic model of terrorist decision making to understand the role of nuclear detection technologies in deterring nuclear terrorism. The results suggest that unless the defender imposes high retaliation costs on the attacker, 100% inspection is likely to be needed, and deterrence with partial inspection may not be achievable in practice even though it is possible in theory. On the other hand, when the defender can credibly threaten the attacker with costly retaliation, partial inspection may be sufficient to deter nuclear smuggling attempts. Sensitivity analysis of these results indicates that these observations are robust to assumptions about specific parameters in the model. Thus, for policy debates about how to prevent nuclear terrorism, consideration of the diplomatic stance on retaliation is as important as, or maybe even more important than, debate about the optimal percentage of containers to inspect.