Without al Qaeda and its terror campaign against the West, Afghanistan would still be a mess. If the Russians had not invaded to protect the local communists, Afghanistan would still be an collection of tribes presided over by a Pushtun king, and eventually corrupted by drug lords. The heroin trade was going to be driven out of Burma (the Golden Triangle) eventually, and Pakistan was the likely place for it to move to. The Pakistanis were pretty united in driving out the heroin trade, which they did, and it moved into Afghanistan, where it naturally thrived in the largely lawless tribal confederation that has existed there for centuries. Even without Islamic terrorists and Western troops in Afghanistan, there would still be an “Afghan Problem,” but it would mainly be about the place being the source of the world’s heroin supply. Modernization would still be taking place (the largely illiterate Afghans quickly came to love TV, cell phones and SUVs), and causing friction with traditionalists. The end of the Cold War would have brought a flood of cheap Cold War surplus weapons (mainly from the former communist states, and including millions of AK-47s selling for as little as twenty dollars each).
The “Afghan Problem” would still consist of drug lords, a largely illiterate tribal population, torn by those seeking to preserve the old ways, and a minority seeking reform, or a way to escape to the West (or anywhere else.) The “enemy” in Afghanistan is a lot more than the Taliban, and victory won’t come quickly or cheaply.