What Really Happened in Afghanistan ?
Why did the U.S. fail in Afghanistan? (I know we are pretending to have succeeded, but that's just camouflage to disguise what is in fact an embarrassing if predictable defeat). The reasons for our failure are now being debated by people like Vali Nasr and Sarah Chayes, who have offered contrasting insider accounts of what went wrong.
Both Nasr and Chayes make useful points about the dysfunction that undermined the AfPak effort, and I'm not going to try to adjudicate between them. Rather, I think both of them miss the more fundamental contradiction that bedeviled the entire U.S./NATO effort, especially after the diversion to Iraq allowed the Taliban to re-emerge. The key problem was essentially structural: US. objectives in Afghanistan could not be achieved without a much larger commitment of resources, but the stakes there simply weren't worth that level of commitment. In other words, winning wasn't worth the effort it would have taken, and the real failure was not to recognize that fact much earlier and to draw the appropriate policy conclusions.
First, achieving a meaningful victory in Afghanistan -- defined as defeating the Taliban and creating an effective, Western-style government in Kabul -- would have required sending far more troops (i.e., even more than the Army requested during the "surge"). Troop levels in Afghanistan never approached the ratio of troops/population observed in more successful instances of nation-building, and that deficiency was compounded by Afghanistan's ethnic divisions, mountainous terrain, geographic isolation, poor infrastructure, and porous borders.