It will be his fault along with others, including our next President, because it can still be won with overwhelming force. The fact is the war should have, and could have, been over while Bush was in office. He didn't unleash the full U.S. military without restriction on their use of power while forgetting about nation building. He sent them in with the same unrealistic ways for victory, and our next President will be to blame for our lose or continued policy of fighting to lose, unless there is a dramatic change in policy. Those aren't the only two options no matter how unlikely it is we will actually ever see our military unleashed for total war. We should win the war the way we should have to begin with, and we all know that isn't going to happen. We pullout or stay put getting our guys killed for what we made mean nothing.
I would like to see someone finally admit that we were naive in thinking we could build a civilized pro-American nation in Afghanistan, and have now halted those plans for an all-out destruction of the nation and Taliban strongholds in Pakistan.
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.