System Dynamics Model for Proportionality Assessment in Military Operations

Abstract

This research introduces a System Dynamics (SD) model for proportionality assessment in military operations. This is done under a broader perspective adopted for the collateral damage component considering two cases, as follows. In the first case only collateral physical effects are considered and in the second case a combination of physical and psychological collateral effects are considered. Furthermore, the model comprises feedback loops by linking civilian injury, death, damage to objects, and military advantage to a proportionality assessment stock. With this scope, Monte Carlo simulations over 100 time steps are conducted and revealed that incorporating psychological damage reduces the share of proportional assessments by 7 percentage points and slows the accumulation of proportional judgments. At the same time, the sensitivity analysis shows a steeper decline in proportional outcomes when psychological impacts are included. In addition, further statistical tests are conducted and from a comprehensive evaluation it can be seen that the model provides a robust and interpretable tool for exploring how different collateral‐damage considerations shape proportionality decisions and can inform military rules of engagement and policy debates.