Tactical missions are very demanding scenarios for both pilots and instructors. The pilot expects a flight simulator to provide a realistic simulation while the instructor requires an efficient teaching environment. Artificial intelligence (AI) provides both of these expectations: AI, in the form of an expert system, produces realism through fuzzy logic and it delivers a scenario which is easily generated and modified. The realism goal is achieved by the expert system which uses a set of protocols or rules which define the operation of threats within the tactical mission. These rules are generally English-like statements which the instructor can manipulate to form the necessary mission. This paper describes an IR&D project which combines the use of the Prolog programming language with an intelligent threat reaction system. Prolog is ideal for this project because the language furnishes a rapid development environment, and the expert system, written in Prolog, provides for easy modifications to the scenario. The paper also discusses expert systems in general and fuzzy logic processes specifically as they pertain to the main goal and design of the project.