Financed by Thalès Land & Joint on the period 2006-2007, this project aims to provide tools for examining a geostrategic situation assisted by a knowledge-based model that follows the user, highlights inconsistencies, advises and deduces. This process of searching the meaning of a complex situation is put into effect using graphs associated with mapping resources for viewing, filtering relations and positions between actors. The design work has focused on the relationship between the need to understand a situation in all its documentary complexity which consists of exploring, comparing and annotating - and that of gradually extracting key events necessary for the demonstration of a final analysis.