Most of the discussions in the western press about what we should do in Afghanistan before getting out and coming home, make suggestions about military strategy, institutions and training without taking the political/historical/cultural situation of the country into account.
Let's start with the most important fact that is never discussed in mainstream American discussions about the political future of Afghanistan and that is the geographic-tribal reality. Afghanistan was never ruled as one country. It has always been an archipelago of small fiefdoms organized in tribal regions, which were loosely organized under a hereditary monarchy in the 18th century. At that time the Kingdom of Afghanistan only encompassed Pashtun areas south of the mountains. The central government of the Kings had very little real power outside of Kandahar, although they received enough tribute to be figureheads for the "nation" of Afghanistan. The Kings were able to unite the tribes to throw out the British Empire twice, they made Kabul their capitol and in the 20th century they built some roads and power lines but the Kings never ruled over most of the country, especially not the non-Pashtun areas north of the mountains, which were only nominally Afghanistan.
The last King, Mohammed Zahir Shah (ruled from 1933 to 1973) united the country more than any of his predecessors. In order to unite the north slope of the Hindu Kush with the Pashtun areas south of the mountains, the King enlisted the help of the Soviets in the early ‘70s. That decision was one of the ingredients of his downfall and the demise of the monarchy. and the series of crises that Afghans have faced since 1973 when the King was deposed by Mohammed Daud Khan, who was subsequently deposed and killed by his allies in the People's Democratic Party of Afghanistan. As soon as the PDPA grabbed power in 1978 they requested Soviet assistance and rolled right over the Hindu Kush on the road the Soviets built five years before.
Afghanistan's geography is separated into myriad little districts that are divided by uninhabitable deserts and huge imposing mountain ranges. The country is not interconnected like the USA or Europe, and this is especially true in the division between Afghanistan north of the Hindu Kush and south of the Hindu Kush. Until the Russians built their road and tunnels over the mountains in the 70s http://en.wikipedia.org/wiki/Salang_Tunnel, there was no way to travel from one side of the mountain range to other in the winter.
The two geographic divisions are also tribal/cultural divisions. North of the mountains there are very few Pashtuns. The population is predominantly Tajik, Uzbek and Hazara. South of the mountains it is predominantly Pashtun. Way over 90% of the attacks on NATO are committed by Pashtuns. The Taliban are all Pashtuns. The Afghan Army is just the old Northern Alliance, armed by the USA.
Here is a map of cultural distribution.
And a map of the physical characteristics of Afghanistan.
Please note how the cultural and physical areas coincide.
So Afghanistan is really two countries and that is the key to solving the problem of what happens when the USA inevitably skedaddles. While NATO still has some time it needs to design its strategy based on what Afghanistan IS, rather than what the US and NATO wish Afghanistan was.
Unfortunately NATO and the US continue to follow the policy from ten years ago. That policy aims to convert Afghanistan into a western style republic with a strong central government that is democratically elected and which fields a national army and police force to maintain order and combat tribal rebellions, otherwise known in the western press as terrorists. The people who promote these strategies don't know Afghanistan. They know the military bases and they know the insider-Washington, upper-echelon conferences about Afghanistan, but they would not keep advocating the exact same policies that have failed for eleven years if they knew anything about the country in question. Continuing the Obama strategy will mean a humbling defeat and a new Taliban Afghanistan.
There is a possible strategy for a NATO exit that doesn't repeat the Vietnam disaster.
Divide Afghansitan into three independent states which could be associated in some loose federal structure that maintains the name Afghanistan, but which are really independent states, each with its own armed forces. Those three states would be Northistan (I would hope for a better name) on the north side of the Hindu Kush and extending to the border of Iran a few hundred miles south of Herat. The capitol would probably be Mazar i Sharif.
The second state would be Pashtunistan. It would occupy most of Afghanistan not taken by Northistan. Its capita city would be Kandahar.
The third country would be the Emirate or Canton of Kabul and it would occupy the land in the mountain valleys from Bamian in the west to the Pakistan border, including Jalalabad.
Instead of arming the Northern Alliance (Afghan National Army) any further, begin reducing their number drastically and only train the best recruits in order to form the armies of the Canton of Kabul and Northistan. Since the Taliban will be the government of Pashtunistan, they will field their experienced soldiers as the Pashtun Army.
Once the borders have been defined, allow the three countries to choose their own government in THEIR OWN MANNER. If the Pashtuns want to use the Loya Jerga system, thats what they ought to do. In the Canton of Kabul, the US/NATO should probably continue to support Karzai. As the head of state of a little country sandwiched between two warlike countries, he would be happy to have a small US presence and his borders would probably be defensible. He might be able to maintain power with limited American support and he could manage American contacts with all three countries. I believe that the Taliban would be ready to deal with the US on this basis to develop resources, pipelines and infrastructure in Pashtunistan.
This outcome would make Russia and the Stans happy. They don't want a Taliban government on their border again. It would also make Pakistan happy because they would have Pashtunistan as a friendly neighbor to their west. They would not feel squeezed in between a US proxy on the west and India to the east. Iran would be happy to see Afghanistan cut into manageable pieces and would be an ally of Northistan.
There would be massacres of Tajiks, Hazaras and Uzbecks in Pashtunistan and massacres of Pashtuns in the north until people figured out that they should move to a country where they are safer. Kabul could conceivably remain multicultural and continue to guarantee more rights and opportunities for women.
But for some reason that may have to do with worshipping the state, the Washington elite do not think that making smaller, less multicultural states is a good idea. So this idea that could turn Washington's nightmare into a decent outcome will never happen.