The US Afghani occupation is very much like its Iraqi counterpart. Namely we came in and destroyed all local institutions and then added nothing real to replace those institutions.
For all the nutty Islamic aspects of the Taliban, it was the home grown entity that was restoring law and order---and making a modern Central Government possible for the first time since 1937 because the Taliban was reining in the powers of the local warlords that made commerce and national unity impossible.
And our initial occupation act was to ally ourselves with the very warlords who kept Afghanistan in a perpetual state of government by thuggery.---and we have now brought government by thuggery back to most all of Afghanistan. And the only they we have added is a new national government that is so weak that Karzi might as well be the mayor of Kabul. Out in the countryside---the war lords are back in firm control, any sort of national commerce is impossible, opium production has nearly tripled, and we have replaced the Russians as the hated occupiers.
And now we wonder why the Taliban is coming back?