And as part of a larger context - we need to scale our electrical power generation 500% in the next 40 years (from 300GW to 1500GW). Alternative energies won't scale fast enough, IMHO, fossil fuels are out, and normal nuclear will use up all of our uranium in very short order. The end result, as I see it, is breeder reactors, which means that everyone in the world will have access to plutonium based nuclear weapons.
Large countries with free trade ties are safe, because they have too much to lose. China and the US will never go to war, so they are both trustworthy enough so that nuclear weapons are not a problem. Small countries are a problem, though.
I don't think we can suffer small countries to live, they are too unstable to trust with the nuclear weapons that they will eventually get (just think of Somalia with nukes). We need to invade Africa to merge it into a superpower.
If we could get them to merge up without a war, that would be even better, but it doesn't seem to be happening. Forming a superpower is obviously in the best interest of Africans, so if it was going to happen it would have already happened...