You are right that the Anbar expereince will not be duplicated with the Pashtun in the mountainous regions. Pakistan tried to make deals with them, but they just took the money and then reneged on every promise.

The real change was not the surge in troops but the change in strategy from “kill 'em all” under Sanchez to true “hearts and minds” under Petraeus. Anbar's Awakening movement was simply repeated in Baghdad neighborhoods as well as Diyala. Meanwhile, largescale ethnic cleansing in Baghdad neighborhoods rendered the neighborhoods largely homogeneous. With this landscape, many of the surge troops spent their time constructing massive walls to separate the neighborhoods and keep the violence down. It worked in Baghdad.

The key in Baghdad as elsewhere in Iraq was the separation of ideological Islamist extremism from Iraqi nationalist insurgency. While there was plenty of cross-pollinization between the two groups, there was also a major divide between the Risha nationalists and the Al Baghdadi/Zarqawi Islamists.

Sadly, no such divide exists in Afghanistan. The Taliban is a Pashtun organization based on Pashtun history. The Al Qaeda Arabs were deeply unpopular in Afghanistan. But the local Pashtun extremists were another matter. And unlike Iraq, there seems to be no separation between Pashtun nationalists and the Taliban.

There is another common factor with iraq: military force alone can't win the war.
One reason (though far from the only reason) Pakissitan has been loath to pursue extremsits is that civilian casualties can produce a bcklash of such magnitute as to undo any good military actions have done.
Basically, Aghanis want security and a means to make a liveihood, just like Iraqis do. That's a starting pint.

NATO and US forces have been slow to develop the right mix of military action and hearts-and-minds strategies,so far. Some countries won't fight at all. The outpost of US troops which was recently attakced was an attempt to develop a relationship of trust with the locals, though, so it seems the US has recognized the need for a dual approach.

Because the situation was allowed to unravel so much, sending in more troops won't, as Jazz says, be of much help in itself. A lot depends on how the new troops are used. Developing relationships of trust requires adequate manpower, and we can hope that the additional troops will be used in those efforts as well, and not just for military attacks.

i don't know if the omission of details by the candidaes was intentional, but in one sense, it was wise. First, the oublic has to be reminded about the bad shape Afghanistan is in, and the role that has in the WOT. For Obama, the esssential point was to put his plan to withdraw troops from iraq in the context of this larger vision for the region and Afghantistan. Now that the economy is topic #1, even that much will be difficult.
i only wish he had stressed the economic connection more.

if the question is 'why send additional troops at all?' The answer is that politically, the public would not support abandoning Afghanistan, and for the present, there is no choice but to continue. Besides, allowing these safe havens really is dangerous and a very bad idea.