Dexter Filkins, in his nearly hagiographical profile of Gen. McChrystal, summarizes the aims underpinning McChrystal's call for more troops for Afghanistan as follows:
What McChrystal is proposing is not a temporary, Iraq-style surge — a rapid influx of American troops followed by a withdrawal. McChrystal’s plan is a blueprint for an extensive American commitment to build a modern state in Afghanistan, where one has never existed, and to bring order to a place famous for the empires it has exhausted. Even under the best of circumstances, this effort would most likely last many more years, cost hundreds of billions of dollars and entail the deaths of many more American women and men.In other words, the goal is to turn the most socially and politically devastated country on earth, one rife with hostile religious fanatics, into a kind of Asian Switzerland. No duh that's going to take a lot more troops and resources.
Let's be blunt: this is completely insane as an objective--insane in the same way that jumping out of an airplane with no chute is insane. Nation-building of this sort has never succeeded anywhere, and not for lack of trying. What's more, if that's the objective, then the resource commitments that McChrystal is asking for are bathetically modest. The 40,000 extra troops that McChrystal wants aren't going to come anywhere close to doing the trick.
There's an entirely different alternative, of course, which is to redefine US and NATO objectives in Afghanistan, and to match the resources to meet that redefined objective. Here's one thumbnail alternative: pull back from local commitments, work on developing intelligence sources, and make it clear that we will kill from afar anyone we can see consorting with known bad guys. It ain't very humanitarian, but at least it's a project that can succeed and won't bankrupt the nation.