Afghanistan grows the seeds of the drug trade that is their "cash crop" until a few years ago when someone found a few zillion square miles full of litium. (see entry here). Then comes a ramp up of troops to fight in a country that has 4-5 dozen bad guys scattered here and there and bingo we are 2 billion $'s a week and 150,000 troops and no one is sure what we going to do when we succeed in doing it. What is for sure is that lithium is of interest to us and we are not going to let it go without a fight.
Here is a list of the oil producers. Note that it is a couple years old but fairly representative of country by country production. It is also a list of places, in order of importance, where we will participate in no-fly zones or send troops or both. I suppose that if there was another column to the right that noted the 'despot/dictator" index, we could refine it even further.
I'm pretty certain that the big oil lobby is in full throttle at the Pentagon and in the Halls of Congress making sure we "do the right thing" on behalf of the folks fighting for "freedom" there. I'm also pretty sure that they won't give up their tax breaks to help pay for the few million a day soon to be a billion a week it will cost to be involved.
I'm pretty sure they won't be paying for any of the funerals either.