The Register (UK) has an article on the US DoD's use of simulation to explore a wide range of scenarios.
Called the Sentient World Simulation (SWS), it will be a "synthetic mirror of the real world with automated continuous calibration with respect to current real-world information", according to a concept paper for the project.
"SWS provides an environment for testing Psychological Operations (PSYOP)," the paper reads, so that military leaders can "develop and test multiple courses of action to anticipate and shape behaviors of adversaries, neutrals, and partners".
SWS also replicates financial institutions, utilities, media outlets, and street corner shops. By applying theories of economics and human psychology, its developers believe they can predict how individuals and mobs will respond to various stressors.