It's fun to think of one but I don't think it would actually work. Here are a few problems.
America is unquestionably the strongest military nation in the world. Other countries often have to get Americas nod of approval before going to war and certain parts of the map are off limits (North and South America.)
Nukes are overpowered. The two which were dropped in WWII are very~ weak compared to modern versions. During the Cold War, America developed nuclear warheads which also divide multiple times after launch. This means that you don't need a nuke per province. You shoot those and they divide to hit the major cities.
This leads to the third point. Nuclear nations are fighting with kid gloves now. Nations don't want to unleash their full power. The recent American conflicts have very little to do with a true full on war. The larger nuclear powers don't want to fight either. Russia knows that America has a stronger military but they are counting on war weariness and the nuclear deterrent to prevent a conflict as they are annexing nearby states. It's kinda like this... Imagine you want to kill a deer near your house (I am not a hunter and am just using the deer as an example). One person has a rifle, the next person has a rocket launcher, the next a bomb, then a nuclear bomb equivalent of Hiroshima, then a modern nuclear bomb. Is the modern nuclear bomb substantially stronger than the historical nuclear bomb or a regular bomb? Definitely! Does it matter? Not really, either way the deer is going to die. so would it be fun to play a game in kid gloves all the time?
Last point and I'll stop so it doesn't get too long. Countries no longer expand just because they can. Expanding can actually hurt your country far more than it helps. America could conquer Mexico if it wanted. It would actually make America weaker to do so. That would be odd to have in a game.