There will be no definitive end to Afghanistan just as there will never be an end in Iraq. Likely U.S. troop withdrawal in Afghan will begin late this year or in early 2011, and total recall of troops will be completed in two years. That will coordinate loosely with the 2012 elections which the Dems want to win. The Dems merely want to say "We finished what Bush started."
The U.S. dare not leave a skeletal presence in that region as it would be decimated. So once U.S. troops are withdrawn, Afghan will once again be subject to constant upset and puppet governments. It has nothing to export and no income source except for poppies (drugs). This entire adventure -- and billions of dollars -- will be for nothing. Yet, this country will no doubt fund another skirmish in the near future.