Well said, WE, an additional complication in Afghanistan is the neighboring and essentially lawless tribal uplands which are nominally part of Pakistan. It is essentially an arid and cold version of the Viet Nam problem, a large enemy sanctuary and base area, immune from attack and immediately adjacent to our zone of operation with no natural geographical feature to mark the border.
Such situations can only be addressed by inflicting so much pain in the sanctuary that further hostilities become unsustainable (fat chance in Afghanistan and the Pakistani frontier, they have a long tradition of being willing to engage in murder and mayhem in preference to eating, drinking, or screwing). That requires an enduring and heavy commitment of forces, as well as a certain indifference to the nominal sovereignity of the sanctuary territory, which is just not going to foreseeably be a part of the Obama administration's palette.