The Taliban are not, and have never been the enemy of the United States. IAW principles of Pashtunwali they refused to give up AQ to the US when we asked them to, so we put our weight behind their enemies, lifting the Northern Alliance into power.

Now the Taliban hold the keys to Al Qaeda's sanctuary in Pakistan. That is an essential, and too often overlooked fact.

It is not within the Government of Afghanistan's power to deny sanctuary to Al Qaeda.

It is not within the Government of Pakistan's (or the ISI or their Army for those who demand granting the government amnesty for the actions of its arms, and to also grant sanctuary from consequence to those arms as well) power to deny sanctuary to Al Qaeda.

The mission given to the U.S. by the President is:

“to disrupt, dismantle, and eventually defeat al Qaeda and to prevent their return to either Afghanistan or Pakistan.”

Now maybe it is more effective to build Afghanistan into a modern State, while suppressing that element of their populace that is not particularly down with the form of government put together by Mr. K and his friends.

Maybe it is more effective to disrupt the balance between India and Pakistan by destabilizing the shaky hold that the Pakistani government has on the reins of power there.

Maybe. Personally, I think it is probably smartest to go straight to the Taliban and cut a deal with them. That does not mean giving them the keys to Kabul, as many will immediately jump to. But it does mean not dedicating ourselves to denying them the opportunity to once more engage in the political process of their own country.

This should be fairly obvious, but clearly it is not.