Well, this is indeed a dark assessment. The following quote is important.

... he concluded, it is still possible to develop a stable Iraq. But, he added, "We have very little time left." The dilemma facing the U.S. government, he said, is that U.S. forces probably will have to be reduced substantially within three years, but the insurgency will go on for many years more.

I am usually loath to push my own posts, and have no done so to date over this forum. But this point is so significant that I'll break my own rules and mention that as I have observed from a distance the wisdom, knowledge and experience displayed at the SWJ, the one thing that has concerned me is the notion that this could be like any other COIN operation in terms of duration. In my equally dark assessment entitled Concerning the Failure of Counterinsurgency in Iraq, I said:

It has been said that successful COIN warfare takes ten years on average. Even if this is true, we do not have ten years to perform COIN operations in Iraq. And the U.S. public is not to blame. Four years has been given to the administration, and at least the first couple (after the toppling of the regime) were squandered. This squandering of time and resources, while it affected public sentiment in the U.S., affected Iraq even more. The U.S. public, even now, is likely to give the administration longer than the situation on the ground in Iraq will allow. The critical path to solving Iraq doesn’t rest with public sentiment. If Iraq is a killing field sustaining an exodus of refugees to Syria and Jordan as it appears is the case, we simply do not have ten years. The basis for this boundary condition is Iraq, not the U.S. The same COIN strategy, six years from now, will see the annihilation of the Sunni population and rise of Iran as the only true power in Iraq.

We don't have ten years with OIF, and never did. So what would work / would have worked? The contributors to the SWJ have a better chance than I of arriving at the answer to this question. But it seems that we needed COIN on steroids to make OIF work. My post linked above is dated and the security plan seems to be improving the situation measurably. Further, while I do respect Rick's assessments, he tends to be rather dark, and combining his dark assessments with mine might be piling on.

But there seems to be a continued attempt to implement the ten-year-COIN paradigm, exemplified by the release of the high ranking Sadrist to attempt to reconcile with the Sunnis. Once again, I loath the dark assessments, but in my most recent, I said:

At the standdown of the surge and security plan, Sadr will return to Baghdad, heavily guarded, to women crying and waving their scarves in the air, and men shooting their AK-47s and and swearing to kill on command. Sadr will be received back as not just a hero, but as someone almost divine, who stood down the U.S. Any capture of Sadr and turnover to the courts of Iraq would have the opposite outcome of that intended, because no Iraqi court will convict Sadr of crimes, thus exhonerating and codifying him in his rule of his followers.

Iran will then have their forces deployed in Lebanon, headed by Sayyed Hassan Nasrallah, and in Iraq, headed by Moqtada al Sadr. Only confident actions by the administration - rather than acquiescence by the State Department - will avert such an outcome.

It might seem rather pedestrian to some to have recommended the "strategic disappearance" of Sadr as I have, but McCaffrey's point is salient and unanswered. The U.S. will have to stand down at some point, since the current infrastructure will not support the continued heavy deployments. Mentally, we went to war with the forces that Reagan built, while actually we went to war with the forces deconstructed by the subsequent administrations and congressional laziness. Pedestrian though it may seem, the strategic removal of those who would lead the insurgency - rather than WHAM - might in fact be the COIN on steroids that has been needed. We have taken this approach with AQI and AAS, removing them as actors when we could by taking robust kinetic operations against them. To take any other approach with the Mahdi army and the hard line Sadrists is sure to be a losing proposition.