Optimal cheating and inspection strategies under a chemical weapons treaty

A chemical weapons non-production agreement including limited numbers of short-notice inspections at specified facilities is a definite future possibility. The verification aspects of such a treaty would present new and important strategic problems which are studied here for the case of a single production site. An inspector must select when to inspect the facility, keeping in mind the length of time remaining in the treaty and the limited number of inspections permitted under it. The inspectee must determine and adjust the level of cheating-cheating more increases the inspectee’s gain if undetected but also increases the probability of detection in an inspection. These choices are modeled by a two-person zero-sum sequential game which has optimal strategies and a value that can be determined inductively. This model yields numerical and analytic results which have significant policy implications when interpreted in the context of chemical weapons treaties.