Supreme Ruler Cold War have a "Modern World Scenario" mod, it's pretty nice, but, as Dick Dastardly said, the game have some issues. But, it's the *only* modern geopolitical simulator.
I'm interested in smaller scale WW3 games, but I only play singleplayer, so looks like Wargame: EE isn't a nice option (from what I've read of the AI and campaign). But looks like the next Wargame, "Airland Battle", will have some sort of dynamic campaign, I'll keep my hopes up to the possibility of a kind of modern "Total War" game.