Whatever else Hamid Karzai may be, he's always been a survivor. And now he's trying to survive the Obama Administration. Karzai knows that unlike Bush, Obama has no commitment whatsoever to Afghanistan. What Obama wants is to pull out as quickly as possible in time for his own 2012 election. And he wants to do it without the appearance of a disaster and a defeat. And there's only one way to do that, cut a deal with the Taliban.
To that end, the Obama Administration is operating on two tracks. Track 1, the public and visible track, is the military approach that Obama got pushed into, a temporary surge to push back the Taliban and allow him to declare victory ahead of a pullout.