The U.S. Department of Defense has created a number of training games ("wargames") using commercial game technology, and there's a non-military website that lists them all (at least the unclassified ones.) The Social Impact Games sites shows what the Department of Defense is up to HERE.
But there is also a section of the site showing combat simulations by other organizations (some of them pro-terrorist.) These are HERE.
The www.socialimpactgames.com site is worth a look if you are interested in combat simulations from many different sources, and in different styles. The site covers many non-combat games as well.