The Afghanistan invasion was a complete waste of U.S. and NATO effort and lives. If the purpose was strictly to kill Bin Laden and destroy Al-Qaeda, then the U.S. could have done so without risking a single life.
They could have simply offered to deposit $1 billion in the Swiss bank account of the Pakistani military general who delivers Bin Laden's corpse to the U.S. embassy in Islamabad. Smaller bounties would be offered to other Al-Qaeda leaders.
It would have cost just $10 billion to avenge 9/11, without costing a single U.S. life or jeopardizing NATO's legitimacy, or burdening the west with an intractable problem.
Never mind that the Taliban government in Afghanistan was openly aiding and abetting global terrorists, including Al-Qaeda
Regime change was the only option following 9/11