Afghanistan - Most Important?

Charles Krauthammer makes an obvious case refuting those who say that we should simply focus on Afghanistan, because it is more important :

Thought experiment: Bring in a completely neutral observer -- a Martian -- and point out to him that the United States is involved in two hot wars against radical Islamic insurgents. One is in Afghanistan, a geographically marginal backwater with no resources and no industrial or technological infrastructure. The other is in Iraq, one of the three principal Arab states, with untold oil wealth, an educated population, an advanced military and technological infrastructure that, though suffering decay in the later years of Saddam Hussein's rule, could easily be revived if it falls into the right (i.e., wrong) hands. Add to that the fact that its strategic location would give its rulers inordinate influence over the entire Persian Gulf region, including Saudi Arabia, Kuwait and the Gulf states. Then ask your Martian: Which is the more important battle? He would not even understand why you are asking the question.