Assessment of the operational environment for military operations planning increasingly requires, alongside physical terrain evaluation, the systematic integration of socio-economic, institutional, and security-related data into coherent analytical frameworks. Traditional geopolitical and regional analyses often treat these dimensions separately, limiting the capacity to evaluate territorial stability as a multidimensional and spatially differentiated phenomenon. This contribution introduces the Socio-Economic Area Stability (SEAS) model, conceptualized as a geospatial composite index designed to quantify territorial stability through the structured synthesis of heterogeneous spatial indicators. The model builds upon principles of composite indicator construction and geospatial data modelling grounded in ISO 191XX standards, transforming conceptual socio-geographical structures into a spatially explicit analytical framework. Investigation results confirm that the proposed index architecture is internally coherent, theoretically grounded, and structurally compatible with multi-source spatial datasets.