I have as much right to pontificate about the situation in Afghanistan as anyone else, so here goes.
The question, of course, is: do we send in more troops, and if so how many?
But the bigger question is: what exactly are we trying to accomplish here?
Gen. McChrystal has grasped the basic truths of the situation, from what I've read: straight fighting will not win this, protecting the citizenry from the Taliban and helping to build out infrastructure will win this, but it'll take a long time and a lot of boots on the ground. This is why he's asking for a lot of boots on the ground. I think the reason Pres. Obama is taking a long time to thing this out is because of the implications of the bigger question.
Afghanistan is a poor country; it's mostly a rural country, with only a few large cities. Because of the almost total lack of infrastructure (read: roads), people who aren't in the cities don't get to them much, and people who live in the cities don't go to the country much. Since the total lack of infrastructure also means almost no schools, people in the countryside are poorly educated except in Islam, their religion. The primary organizing force in the countryside seems to be the tribe or clan; national identity is secondary. People in the countryside voted or didn't vote for Hamid Karzai in the recent election because their clan chief told them to; less so in the cities. And like a lot of groups where authority is vested in people, not in laws, there's a lot of corruption - you get something done by paying the right man a bribe.
This is a pre-industrial society. European countries were more or less like this until maybe the 18th century. The Taliban are a major force because the Taliban are a religious army, willing to fight for their cause; most of the villagers are subsistence farmers, who don't have time to fight for a cause or anything else. And how do the Taliban eat, if they don't farm? Extortion from the villagers, of course; it's a protection racket.
So yes, if we can protect the villagers from the Taliban, they'll support us. But if we leave even for a few weeks, the Taliban will be right back in the village; so how does it profit the villagers to support us? The Taliban will take it out of their hides when we leave.
This is why Gen. McChrystal wants all those men. "Securing" Afghanistan means taking, and holding, and defending, every damn village; because every village we don't take, and hold, and defend, the Taliban will take back. And our troops will have to defend the Afghans, plus the people we send to help build infrastructures - roads, schools, telecoms.
The next question is: how long will it take? That's the kicker. We have to do this until we've improved conditions enough that poor young men won't have to fight for the Taliban to make a wage. How long is that? I can easily see us in Afghanistan for a couple of generations - how long will it take until the young men now fighting will be too old to hold power any more, in a society that respects old leaders? How long will it take us to educate an entire generation, an entire society, in the concept of the rule of law?
Our official mission statement is to prevent the Taliban from providing Al Qaeda with a safe haven, because of Sept. 11, 2001. The only reliable way to do that is to take over Afghanistan and run it ourselves. Is that really what we want to do?? Especially since it wouldn't solve the issue of Pakistan, where Al Qaeda is actually hanging out these days (according to most people's best guess)?
I don't have answers to these questions. But there are reasons Afghanistan is called the "graveyard of empires." I don't want it to be our graveyard. I read a comment from a Kabul shopkeeper, who complained that yeah, when the Taliban were in charge, the girls couldn't go to school; but so what, they had great security, they kept the thieves out of his shop.
If that's the way the people of Afghanistan feel, maybe we should let them and the Taliban have each other back, and deal with the country diplomatically and from a distance.