The U.S. Air Force spends over $20 million a year to upgrade and maintain one of its primary wargames (AFMSTT, Air Force Modeling and Simulation Training Toolkit). AFMSTT plugs into many existing air force computer systems and displays used at headquarters, so that senior commanders, and their staffs, can experiment with future wars, military crises or natural disasters.
AFMSTT allows the generals to accurately deploy combat and support aircraft. AFMSTT also allows real exercises (with actual aircraft and troops) to be plugged into a simulated exercise. AFMSTT also models space operations (putting up satellites, managing and defending them, and attacking enemy birds). Most importantly, AFMSTT accurately models logistical (supply) and maintenance operations. This is the most important thing for air force operations. It takes a lot of effort to get the supplies (fuel, weapons, spares) to where the combat aircraft are. This is actually harder to simulate than combat (which is a lot more straightforward).
AFMSTT makes it more likely that when the air force is sent into some future war, they will have a sense that they have been there before.