It's a smart line of questioning. I can certainly see the argument that, regardless of the fact that invading Iraq was a terrible mistake and a catastrophe for America and the region, there is still higher strategic importance for "winning" in Iraq, to mitigate the harm we did, than winning in Afghanistan. After all, if we pull out of Iraq prematurely, it could theoretically come to look like Afghanistan in 2001 -- a chaotic mix of feuding warlords and religious extremists... only with lots of oil money. But even if Iraq has the greater strategic importance, one could still argue that leaving Iraq is our best shot at "winning." After all, unlike Afghanistan, it was a fairly peaceful and stable nation before our invasion, so perhaps it could go back to being one without the constant irritation of US occupation. Maybe what they need is a little breathing room for whoever will be the new power there to consolidate control. By comparison, Afghanistan was in a state of warfare before we ever arrived, and was a playground for Al Qaeda before we entered, so there's not much hope our exit would change that.