I think, first, that we would be morally wrong to launch an all-out attack on Afghanistan. Many innocent people would die. I believe Ben Laden would not hesitate to use innocent civilians, women and children, as human shields. The Taliban has been a cruel and self-serving government. Second, for whatever it's worth, I think it would be unwise.
World opinion is on our side.
Even most Arab nations are sympathetic. And an all-out attack on Afghanistan might well change that. Indeed, we could turn current Arab support into opposition which would delight Ben Laden. I have observed the Israeli-Palestinian conflict for some time now. We can learn something there.