The stakes now are similar to what caused the U.S. to invade almost 11 years ago: the threat of more al-Qaida attacks.
Obama says U.S. forces must not leave until Afghan forces can defend the country on their own. Otherwise the Taliban would regain power and al-Qaida might again launch attacks from there. Rival Romney appears to share that view.
What's often overlooked in the "al-Qaida returns" scenario is an answer to this question: Why, after so many years of foreign help, are the Afghans still not capable of self-defense? And when will they be?
The official answer is by the end of 2014, when the U.S. and its allies plan to end their combat role. The Afghans will be fully in charge, or so it is hoped, and the war will be over, at least for Americans.
In this Thursday, May 24, 2012, photo provided by the U.S. Army, various military vehicles are seen parked after being cleaned and stripped of sensitive items for shipment as part of drawdown of 23,000 U.S. troops by Sept. 30, 2012 at the Kandahar Air Field south of Kabul, Afghanistan. (AP Photo/U.S. Army, Staff Sgt. Michael Behlin.)