May 3, 2009
This paper presents a stochastic game model that comparatively evaluates al- ternatives for improving container security. The players are an attacker who plans to send a nuclear weapon, and a defender who considers two alternatives at two nodes of interdiction along the supply chain. The attacker can choose the path of the container, the method of intrusion and the target, whereas the defender chooses whether to improve transportation security and whether to improve inspections at domestic seaports. The base case results suggest that the attacker chooses to attack by sending the nuclear weapon under the disguise of a front company and through a foreign seaport that does not participate in the Container Security Initiative. The target of choice is likely to be a domestic seaport despite the higher economic toll of an urban area attack. The defender, on the other hand, chooses to improve trans- portation security, but not inspections at domestic seaports if the attacker plans to detonate the weapon before the authorities get a chance to act on it. We run sensitivity analyses to determine the most signicant parameters of the model, and see how the baseline decisions change as a function of these signicant parameters. The results in general recommend strong security measures along the entire supply chain rather than simply at the United States ports of entry. They also suggest that terrorists will probably execute the attack as soon as the weapon reaches United States shores to reduce the probability of interdiction.