What is the genesis of the “nation building” objective? Why not simply “find terrorist, take out terrorist”?
No alternative, really. First of all, the terrorists are not headquartered or produced in Afghanistan, but Pakistan.
At the start, the US faced about 20-30,000 Taliban, and yet, with significant attrition each year, we have ended up still fighting 20-30,000 Taliban. They have perpetual reinforcements of cannon fodder from the Wahhabi madrassas schools in Pakistan. We cannot win a war of attrition with them.
Almost half of Afghanistan’s border is shared with Pakistan, and the Afghan government insists it remain porous, because the Pushtun tribes overlap both countries.
http://www.lib.utexas.edu/maps/middle_east_and_asia/afghanistan_ethnoling_97.jpg
Afghanistan is an artificial construct of two nations, with the Pushtun south “and everybody else” in the north.
Second, Pakistan itself is not really a country, but a collection of overlapping enclaves. The governing faction is just the largest of small, violent minorities. It can barely maintain order inside its cities, much less in the rest of Pakistan. We spent years trying to strengthen the military under Musharraf, to make his faction so strong it would rule the country, but though he had some successes, he couldn’t pull it off.
Their ISI, secret police and intelligence service, is rife with Taliban supporters and sympathizers. Oddly enough, their courts and judiciary are actually *common law*, like our own, except their lawyers and judges are a competing faction that will not allow any serious reforms over the rule of the country. Likewise many of them are Taliban sympathizers as well.
Bottom line, as soon as the US leaves Afghanistan, it will again sponsor the worst of the al-Qaeda and Taliban, but who will not get additional support from other US enemies, like Saudi Arabia, on condition they continue to attack us and Europe.
The madrassas of Pakistan, for its part, are where most of the clergy for Sunni Islam are trained, by Wahhabis and Salafists, who encourage them to be far more radical than the mosques they are eventually hired to around the world.