The mistake with Afghanistan is in believing there is anything remotely redeemable about it. A collection of false religion fanatics still stuck in a time 1500 years ago.
In reality, it should have been nuked from orbit multiple times over. It is the only way to be sure it does not continue.
I agree we should have made an example of them by completely destroying the nation with total war. It should have been brutal and quick with the use of nuclear weapons in my opinion as well. We should have woke up to a video of mushroom clouds coming out of Afghanistan right after the Taliban refused our demands to turn over Al-Queda leaders. We would have probably prevented the Iraq war and all the problems we are having now with Iran if we had made an example out of Afghanistan with, or without, nuclear weapons by conducting a total war that was brutal, fast, and uncompromising. The response should have been so brutal and swift it would make the 9/11 attacks look like the most foolish strategy to make war with us by making them pay with so much more. We could have also shown that we will react to a direct attack on our nation in a much more brutal and aggressive way than we conduct other wars. Bush should have done this as our leader instead of telling everyone we aren’t getting into another Vietnam only to get into the same type of ridiculously long war that ignorant policy is completely to blame. We couldn’t even win WW2 with our modern military using the stupid ways we try to fight wars now because the Nazi and Jap civilians would come before our own troops.