In most ways, I suspect we actually won't learn much from the Afghanistan experience. We have no real strategy now, so there will be no way to assess any lessons learned from that; our metrics are all tactical in nature, so all of our lessons learned are about how to optimize those metrics, while at the same time slipping farther and farther behind in regards to the larger strategic picture.
And this is the reason why someone needs to continue the sincere, transparent assessment, across the tactical to strategic.

Chandresekaran has laid the first stone on the path.