More than 70,000 members of mostly Sunni Arab groups now work for American forces in neighborhood security programs. Transferring them to the control of the Shiite Muslim-dominated government, as policemen and members of public works crews, has taken on a new urgency as American troops begin to withdraw, officials indicated in recent interviews, meetings and briefings.
The day-to-day commander in Iraq, Army Lt. Gen. Raymond T. Odierno, believes that the Iraqi government's reconciliation with onetime Sunni fighters represents the "primary driver of enhanced security" over the next six months, according to internal military planning documents seen by The Times.
"It's a big change," said a top Odierno aide, who spoke on condition of anonymity because such plans have yet to be made public. "It's a shift in the commander's intent."
So far, however, progress has been limited. Officials of Prime Minister Nouri Maliki's government, fearing the creation of a potential rival army, are resisting the move. U.S. military officials fear that opposition could send the former insurgents among the Sunni guard corps, known as concerned local citizens, or CLCs, back into the battlefield.
"We've got a lull at the moment, an absolute lull in violence, but it could go anywhere next year, depending on how the current government reacts to it," Odierno's aide said. "One of our biggest risks are CLCs and which way they'll go."
The aide, like other U.S. officials, warned that the window of opportunity is narrow, and is dependent on the Iraqi government making the Sunni security groups, sometimes called Awakening Councils, part of the official government structure.
"If it doesn't embrace it, you could have the different Sunni Awakenings coming together as a Sunni army that tries to overthrow the government, pushing the country into civil war," the aide said. "It's possible."
The concerned citizens groups now serve as guards in areas where traditional security forces, such as the Iraqi army and police, are not present or are not trusted because of past sectarian abuses.
Not all are Sunnis. But experts on the staff of Army Gen. David H. Petraeus, the overall commander in Iraq, estimated at the end of November that about 80% then under U.S. contracts were Sunni. Each gets paid about $300 a month.
U.S. officials believe the concerned citizens groups have helped reduce violence by fighting extremists linked to the group Al Qaeda in Iraq and by redirecting insurgents.
Those officials, wary of creating parallel constabulary units that would rival government-controlled forces, have ramped up efforts to persuade the Baghdad government to attach the concerned citizens groups to the Iraqi police or civilian work corps.
The move marks an important shift in U.S. efforts to bring rival Shiite and Sunni factions together. Since the start of the U.S. troop buildup, Pentagon officials have tried to get Sunni and Shiite officials to reconcile, a process that U.S. officials acknowledge has largely failed.
The Shiite-led Iraqi parliament approved a bill Saturday that would allow many members of Saddam Hussein's party, most of whom are Sunnis, to regain government jobs, but the measure was not related directly to the citizens groups. The law was approved only after months of debate, and other key reconciliation measures sought by the U.S. have languished.
Although not abandoning their efforts at the central government level, U.S. officials have made the hiring of Sunni guards the centerpiece of their new reconciliation strategy.
Last year, the Iraqi government cautiously supported a move to bring Sunnis who participated in the Awakening movement in Anbar province into the police force. But government resistance has stiffened as groups closer to Baghdad begin making the same transition.
So far, 1,730 members of the concerned citizens groups in the Baghdad suburb of Abu Ghraib have been allowed to become police officers. An additional 2,000 in the capital were accepted as members of the police force during the fall.
But even those limited numbers have been difficult for U.S. officials to clear through the Iraqi government.
"It's still an obstacle," said Army Col. Martin Stanton, the officer on Petraeus' staff who is in charge of the effort. "They're deeply suspicious of any organized group of Sunnis, especially ones that were former insurgents."