What's left (as an option for the US in Iraq)? It's possible, as Microsoft has found, that there is no good monopolistic solution to a mature open-source effort. In that case, the United States might be better off adopting IBM's embrace of open source. This solution would require renouncing the state's monopoly on violence by using (Shiite and Kurdish) militias as a counterinsurgency.John Robb, October 2005, in a New York Times Op-Ed. (if you add Sunni militias to the mix, a gross oversight on my part but implied in the approach, it is spot-on analysis).
The Sunni Tribal Awakening (rather than "the surge") has radically slowed violence in Iraq by bringing it back to the levels of activity seen in 2005. That's a good thing, but the Awakening has been wrongly attributed to a new (resurrected) counter-insurgency doctrine (COIN). Here's why. The main objective of United States COIN doctrine is to enhance/extend the sovereignty and legitimacy of the host nation. Everything that is done is slaved to this top level goal. Unfortunately, the development of legitimacy is a long and slow process that takes decades of effort (if it can be accomplished at all). In contrast, everything about the Tribal Awakening is diametrically opposed to this. It arms and trains militias and groups that aren't loyal to the host nation and thereby diminishes the host nation's legitimacy by undercutting its monopoly on violence and its control over sovereign territory.
What did happen with the Awakening, and the speed of the transition should be a clue to this, is that the US military opportunistically embraced the insurgency (in a move akin to IBMs embrace of open source development in the 90's). This embrace showered autonomy, weapons, money ($300 per month x 60,000 participants), protection (from Shiite militias and the Iraqi government), and training on insurgent groups. By doing so, it replaced the ISI (Islamic State of Iraq, an al Qaeda affiliate) as the leading participant in the insurgency. The only "cost" to these insurgent groups, which were under extreme pressure from Shiite militias due to overreaching by the ISI, was to sacrifice the ISI. They rapidly complied.Where this goes from here is problematic since (and I say this to get you thinking and not to shock you) the US is now leading both the insurgency and the counter-insurgency in Iraq.