Given the military tactics displayed during the Clinton administration during Bosnia and Desert Fox, there is, IMO, a better than even chance that the mode of retaliation that Al Gore would have taken would have been heavy aerial and cruise missile attacks on terror strongholds and centers of power in Afghanistan, and maybe some extremely limited ground troops attacks.

Whatever you do--no U.S. casualties!

After a few weeks, victory would have been declared, photos of destroyed Afghan terror camps displayed, and a largely unharmed Air Force would have come home to a victory parade.

I would bet money that Gore would not have attempted nation-building, to actually create a democracy in Afghanistan. Maybe this would have been a good thing in the short run, but in the long run, what good would it have done?