Bush gives the Taliban an ultimatum to hand over al-Qaeda and otherwise cooperate in exchange for recognition and development aid.
When the Taliban inevitably refuses, there's a short, brutal, air campaign against them and al-Qaeda, maybe some special operators go in, but no invasion. Best case scenario, air power and SpecOps(not just immediately, but a sustained air/SO campaign against any new camps that crop up) break AQ enough where they can't strike again, and the whole thing is a historical footnote, as are the few short air campaigns against Iraq and Iran.
Bush wins reelection in the face of a growing economy. He's able to get through his Social Security reform plan(with the economy growing as in OTL and little foreign distractions, he's able to sell it to the American people.) There's still Hurricane Katrina and a subprime mortgage crisis leading to a recession, though maybe the latter is is delayed a few months or otherwise doesn't tarnish Bush's record too badly. Bush is remembered as an above-average President.