Even more than the 2007 surge of U.S. troops, it was the earlier Sunni Awakening which helped dramatically seduce the sectarian carnage in Iraq. While Colonel John Tien called it "the tipping point in Anbar province," the BBC cited U.S. soldiers insisting it was the Awakening, not the Surge, which was "the game changer." But now it appears that the Sons of Iraq can't be bought, only rented. With the continued political impasse in Baghdad, thousands of former Sunni insurgent are deserting the Maliki government to rejoin their old Al Qaeda alliance.
As of July, the Pentagon estimated that only 41,000 of the 90,000 plus Awakening fighters had been offered jobs as promised by the government in Baghdad. And as the New York Times warned Sunday, the tide of the co-opted is now turning back the other way:

Although there are no firm figures, security and political officials say hundreds of the well-disciplined fighters -- many of whom have gained extensive knowledge about the American military -- appear to have rejoined Al Qaeda in Mesopotamia. Beyond that, officials say that even many of the Awakening fighters still on the Iraqi government payroll, possibly thousands of them, covertly aid the insurgency.
The defections have been driven in part by frustration with the Shiite-led government, which Awakening members say is intent on destroying them, as well as by pressure from Al Qaeda. The exodus has accelerated since Iraq's inconclusive parliamentary elections in March, which have left Sunnis uncertain of retaining what little political influence they have and which appear to have provided Al Qaeda new opportunities to lure back fighters.

That worrisome development was highlighted by a flurry of stories about the resurgence of the insurgency in Iraq just as the Obama administration was proclaiming the end of U.S. combat operations. In late September, the Washington Post reported:

Hundreds of police officers, formerly members of an American-backed Sunni paramilitary force, will be stripped of their ranks in the Sunni Arab province of Anbar, tribal leaders and Anbar police said Sunday.

In response, Ahmed Abu Risha, the head of the Awakening and a tribal leader in Anbar warned, "This committee in the Ministry of Interior is sectarian." Abu Risha added:

"When you dismiss those who fought al-Qaeda in the streets, this is support for al-Qaeda. What I expect are dire consequences."

The next day on September 27, the New York Times proclaimed, "Insurgent Group in Iraq, Declared Tamed, Roars." As violence escalated in the weeks preceding the American withdrawal of combat troops, the Times explained:

This spring, United States military commanders said that Al Qaeda in Mesopotamia was a group in disarray, all but finished as a formidable enemy after American and Iraqi troops had killed or captured more than three-quarters of its leaders...
How Al Qaeda in Mesopotamia has managed this unlikely turnaround -- from a near spent force to a reinvigorated threat to Iraq's democracy in a little more than two months -- is a puzzle to both the Americans and Iraqis who study the insurgent group, some of whom now wonder whether the organization in Iraq can ever be entirely defeated.

Hadi al-Amiri, former leader of a Shiite militia and also of the Parliament's security committee, concluded "The people who said Al Qaeda in Iraq was finished were fooling themselves."
Or merely bought themselves time, as the Sunni insurgency was diminished and deferred by the U.S. military's Sons of Iraq payroll.
In November 2007, the Shiite-backed government of Prime Minister Nouri al Maliki fretted about precisely that development. As McClatchy detailed three years ago:

Dr. Safa Hussein, Maliki's deputy national security adviser and the head of a committee tasked with reconciling Iraq's rival factions, said the government was increasingly concerned about what would take place once the United States no longer was supervising the "concerned citizens" groups closely.
"We have tens of thousands of people who are carrying weapons on a contract basis, and when their contracts are finished where will they go?" he asked. "The Ministry of Interior and Ministry of Defense can't absorb them all, and the problem is they are growing very rapidly and the Iraqi government doesn't have any control over that."
"When the U.S. leaves, what we'll have are two armies," said Sami al Askari, a Shiite lawmaker who speaks to Maliki daily. "One who's loyal to the government and one not loyal."

The situation is not yet that dire. But time is not be on the side of the United States. The political impasse since the deadlocked parliamentary elections in March remains unresolved. A rumored power-sharing deal has yet to materialize between Maliki's State of Law bloc and the secular Shiite Iraqiya group of Ayad Allawi. And while the sniping between Allawi and Maliki over Iranian influence and other issues continues, the AP reported:

The U.S. Embassy in Baghdad issued a new warning Sunday that Americans and other Westerners who live and work in Iraq -- and especially in Baghdad -- may be kidnapping targets. The statement followed similar warnings on Sept. 14 and Sept. 25 that cautioned U.S. citizens from traveling in Iraq's mostly Shiite south.

Returning Thursday from a trip to Baghdad, Senator Sheldon Whitehouse (D-RI) said U.S. Ambassador James F. Jeffrey told him that "conditions are ripe" for the creation of a new Iraqi government that enjoys the support of "a significant parliamentary majority." Hopefully, those conditions are sufficiently ripe to prevent the Sunni Awakening from turning into a nightmare.
UPDATE: The Los Angeles Times reports that the Obama administration, worried about growing ties between Baghdad and Tehran, is now pressing the Kurds not to join the Maliki-Sadr alliance. Instead, Vice President Biden is still pushing for a more Sunni friendly national unity government including Allawi's bloc.