Two months ago, a dozen Sunni insurgents — haggard, hungry and in handcuffs — stepped tentatively into a U.S.-Iraqi combat outpost near Baqouba and asked to speak to the commander: "We're out of ammunition, but we want to help you fight Al Qaeda."

Now hundreds of fighters from the 1920s Revolution Brigades, an erstwhile Sunni insurgent group, work as scouts and gather intelligence for the 10,000-strong American force in the fifth day of its mission to remove Al Qaeda gunmen and bomb makers from the Diyala provincial capital.

Little so well illustrates the Middle Eastern dictum: "The enemy of my enemy is my friend."

And as it struggles in the raging heat and violence of central Iraq, the U.S. military appears to have bought into the tactic in its struggle to pull what victory it can from the increasingly troubled American mission in Iraq, under congressional pressure for a troop pullout and a presidential election campaign already in the minds of voters.

Each U.S. Army company in Baqouba, an hour's drive northeast of Baghdad, has a scout from the Brigades, others have become a ragtag intelligence network and still others fight, said Capt. Ricardo Ortega, a 34-year-old Puerto Rico native of the 2nd Infantry Division.

The Army has given some of the one-time insurgents special clothing — football-style jerseys with numbers on the chest — to mark them as American allies.

U.S. commanders say help from the Brigades operatives was key to planning and executing the Baqouba operation, one of a quartet of U.S. offensives against Al Qaeda on the flanks of the Iraqi capital.

The informants have given the American troops exact coordinates of suspected Al Qaeda safe houses, with details down to the color of the gate out front, said Lt. Col. Avanulas Smiley, 40, commander of the 1st Battalion, 23rd Infantry Regiment and a Tacoma, Wash., native.

Most of the Brigades members, whom U.S. officials call "concerned local nationals," hail from eastern Baqouba, while the bulk of the fighting has so far raged in western Baqouba.

But with contacts among fellow Sunni fighters on the city's west side, they have fed American soldiers critical information about Al Qaeda positions.

The American decision to bring insurgents into the mission has angered Shiite Prime Minister Nouri al-Maliki who told visiting Defense Secretary Robert Gates last week that the tactic — getting too cozy with former enemies — would backfire.

But U.S. officials defend the strategy, first tested in Iraq's once-volatile western Anbar province, where U.S. officials tout success in turning Sunni tribal leaders against Al Qaeda.

"We've given them a little ammo, some flares, but mostly humanitarian aid. We're not arming these guys, we're just changing the direction they're pointing their guns in," said Lt. Gen. Raymond Odierno, the U.S. ground forces commander, who made a one-day visit to the Baqouba battlefield this week.

U.S. commanders turned down the Brigades members' request for ammunition when they straggled into the U.S. post in Buhriz two months back. American intelligence spent weeks vetting the volunteers before they started lining them up for the operation that opened in the early hours Tuesday, said Command Sgt. Maj. Jeff Huggins, a 41-year-old Honolulu native of the 2nd Infantry.

Despite intelligence checks, there is concern that some of the Brigades men, or people close to them, tipped Al Qaeda to the coming offense. Odierno said 80 percent of Al Qaeda leaders managed to flee the city before American soldiers stormed into Baqouba before sunrise Tuesday.

The troops found roads with buried bombs and booby-trapped houses across the city.

The men who first contacted American forces in April had been picked up by Iraqi police after a bloody gunfight in nearby Buhriz, and taken to a joint U.S.-Iraqi outpost, where they asked to speak with U.S. military officials.

Al-Maliki complained that the U.S. was turning them and other Sunni insurgent groups into nothing but better trained and armed Sunni militias that will torment the Shiite population and turn their guns on Iraqi troops and police once U.S. forces leave the district.

The group says it abhors the killing of Iraqi security forces, and a commander, speaking on condition of anonymity out of security concerns, said his group turned against Al Qaeda over just that issue.

"We do not kill police or army members, or call for their killing," he said. "Al Qaeda threatened us for taking this stance. ... They began to kidnap and kill our fighters, so ... we began to fight back."

That leaves open whether the men will revert to form — their history of killing American soldiers. The commander would not address this.

The commander said his group had turned down a previous request from U.S. officials to join the fight against Al Qaeda.

"But after recent killings among our Iraqi people in the province, we decided to fight alongside Iraqi and American troops," he said.

Maj. Gen. Abdul Karim al-Rubaie, an Iraqi army commander who works at a U.S.-Iraqi operations center for Diyala province, said his troops are comfortable working with the 1920s scouts.

And he suggested that help from the Sunni insurgent group could lend legitimacy to the Shiite-dominated Iraqi security forces in the area. Baqouba's civilian population is majority Sunni.

"I've found them very beneficial — they've helped us in Buhriz and Tahrir (neighborhoods of Baqouba)," said al-Rubaie, a Sunni. "They're fighting on the side of the Iraqi army with enthusiasm, and without requesting a lot of money or weapons."

To U.S. officials here in Baqouba, the Brigades members offer a window into Sunni divisions where American forces can apply pressure.

"They're grassroots, organized — even like neighborhood firemen — and they've decided they want a safe environment," said Brig. Gen. Mick Bednarek, deputy operations commander for the Army's 25th Infantry Division. "Will we leverage that? Darn right we will. And is it a potential risk? Sure it is — but it's one we're willing to take."