That was what I mentioned. The US will only attack a nation if the cost of the war is significantly lower than the revenues from it. Iraq produces crude oil worth some $95 billion every year. Add to that the huge natural gas production. I am not sure about the American expenses in Iraq, but I think that the expenses will be slightly less than that amount.

Regarding Russia, the cost can reach trillions of $$$. Definitely not worth it.

@Pagan

I don't want to further derail this thread with offtopic, I'm just going to say that comparison with the secession of Croatia stands, but in this case Ukrainians are actually playing the role of Yugoslavia and its forces, while ethnic Russian Ukrainians are like Croats: their methods are very similar to those used by then illegal Croatian paramilitary. Only difference is that the Russians aren't nearly as violent as Croats.