Probability update for risk assessment of dreaded events in asymmetric warfare

This paper presents a new method to update the probability of occurrence of a dreaded event, according to environmental influencers and reports of evidence on the presence or absence of such occurrence. It is particularly useful in military contexts at the tactical level for the risk assessment of a task. Indeed, the computation done during the planning of such a task often uses unprecise values (e.g. average height of buildings in an urban area) and forecast data (e.g. weather, presence of other Blue forces in the area) to determine a probability of occurrence of a given type of attack during such a task. Furthermore, new information may have been gathered from several mainly human sources, since the beginning of the task that indicate a presence/absence of the occurrence of the attack at a specific location in the area of the task. This method is based on Multi-Criteria Decision Making technics that handles the environmental influencers, and conditional probabilities that take into account the reports of evidence, including the reliability of the sources and the obsolescence of the reports.