I've noticed your posts, especially relating to military matters.
IMO, most of the attacks (ANA vs US) have more to do with their perception that we somehow violated their PashtunWali code rather than them switching sides.
You have to be SO careful how you speak to these guys. They are not wired like a Western military. If you jump their shit (like you'd do in a heartbeat to a Private if he was F'd up) they will likely take it as an insult to their code. Once that stone is thrown, they WILL pay you back. Their code, however, says nothing about a straight up fight; they will get you-no matter what the circumstances. Once that's done, they can hold their head up again.
One more instance of us trying to impose our values/ethos/culture on a dissimilar culture with disastrous results.