IRAQ - US Offensive On 'Death Triangle'.

Around 9,000 US forces on July 16 launched a fresh operation targeting al-Qaeda militants in farmland south of Baghdad known as the "triangle of death". The operation, Marne Avalanche, is to stem the flow of weapons and militants into the southern part of Baghdad, where US and Iraqi forces are fighting hard to clear them out.

In pre-dawn raids, helicopter-borne troops swept into an area the US military said was an al-Qaeda haven around the Euphrates valley, 35 km south of Baghdad. The terrain, criss-crossed with an extensive canal system, has seen fierce fighting between US forces and militants in the past and at least one air strike was called in during the early hours of the operation. Tens of thousands of US and Iraqi forces are engaged in a series of security clampdowns in and around Baghdad to thwart sectarian violence pushing Iraq towards full civil war.

Shi'ites Against US-Armed Sunni Tribesmen: The New York Times on July 15 focused on Sunni Arab tribesmen armed by the US to fight Neo-Salafi insurgents. But these men are opposed by Iraqi Army troops and police who are mostly Shi'ite. According to the paper, Abu Azzam's 2,300 tribesmen include members of fierce Sunni groups like the 1920s Revolutionary Brigade and the Mujahedeen Army which have fought the US occupation. Now his men patrol alongside the Americans, who want to turn them into a security force to bring peace to a stretch between Baghdad and Falluja called Nasr Wa-Salam.

A few miles away, in the town of Abu Ghraib, Brig. Gen. Nassir al-Hiti and his brigade of Iraqi Army soldiers also have the support of the US military. But they have a different ambition: doing everything they can to undermine Abu Azzam's men, even using a stolen membership list to single them out for wrongful detention. Nassir, a 37-year-old former special forces officer, denies that but says he has strict orders not to support "unofficial" groups and to arrest armed men, no matter who they are. He says he supports those who join the security forces but objects to "those who have Iraqi blood on their hands".

The gulf between Abu Azzam's men and the Iraqi soldiers remains vast, with US troops sometimes having to physically intercede. And it is an unmistakable caution that the full depths of the problems facing Iraq cannot be measured in the statistics about insurgent attacks and sectarian killings which carry so much weight in Washington.

The US has placed great hope in its ties with Sunni leaders like Abu Azzam who have vowed to fight Neo-Salafi militants. But his mostly Sunni group, the Volunteers, is different from the US-allied tribes in the Sunni heartland of Anbar, in part because it patrols only 40 minutes from central Baghdad and close to large Shi'ite districts. So US commanders view this as a crucial test case for whether Shi'ite leaders will tolerate new alliances with Sunni groups.

The New York Times quoted Lt Col Kurt Pinkerton, "a 41-year-old California native who has spent the past months cultivating his relationship with Abu Azzam", as saying: If Nassir's unit, the Muthanna Brigade, is any indication, the outlook is not promising. He said about a month ago, the predominantly Shi'ite Iraqi brigade was assigned a new area and instructed to stay away from Nasr Wa-Salam. But he said he believed the Iraqi soldiers remained intent on preventing Sunni Arabs, a majority in this area, from controlling the zone. He cited a pattern of aggression by Iraqi troops towards Abu Azzam's men and other Sunnis, who he believed were often detained for no reason.

Recently and without warning, Pinkerton said, 80 Iraqi soldiers in armoured vehicles charged out of their sector towards Nasr Wa-Salam but were blocked by a US platoon. The Iraqis refused to say where they were going and threatened to drive right through the US soldiers, whom they greatly out-numbered. Eventually, with Apache helicopter gunships circling overhead and US gunners aiming their weapons at them, the Iraqi soldiers retreated. Pinkerton said: "It hasn't come to firing bullets yet".

A few weeks earlier, he said, a Sunni detainee was beaten to death while in custody of the Muthanna Brigade. And in the past year, he said, Muthanna soldiers detained two of Abu Azzam's brothers, both of whom said they were abused, and raided Abu Azzam's house. Pinkerton's experiences in Nasr Wa-Salam, he said, had inverted the usual US instincts born of years of hard fighting against Sunni insurgents, adding: "I could stand among 1,800 Sunnis in Abu Ghraib and feel more comfortable than standing in a formation of Iraqi soldiers". He credited the Volunteers for taking on Neo-Salafi groups, including al-Qaeda.

Abu Azzam's men, including some local Shi'ites, have been lining up by the hundreds to submit to retina scans and finger-printing so they can apply to join the Iraqi police. Some already stand guard, with loaded Kalashnikov rifles, alongside US troops. Working with the Americans, Abu Azzam's men have helped drive Neo-Salafi militants out of his group's sector.

They have led US troops to weapons stockpiles and prevented car bombings. Markets and neighbourhoods in Nasr Wa-Salam, ghostly just a few months ago, now teem with people. A one-story hospital was just rebuilt with US money, and two new generators sit outside. Not long ago the violence would have made such a project impossible.

Pinkerton said: Residents there now "have more faith and belief in us than in the Iraqi Army. But they don't trust us. And they don't feel comfortable with us". A watershed of sorts came in late April. After a Muthanna Brigade checkpoint was attacked by gunmen, 50 Iraqi soldiers stormed a school-house then serving as Abu Azzam's makeshift HQ, arresting dozens of men and shoving some into the trunks of Humvees. Enraged Sunnis living nearby charged to the scene. A US officer arrived with 10 soldiers. After hours of frantic intervention, the Iraqi soldiers left without the detainees. The episode hardened the mistrust between the US and Iraqi units, he said, "but it built credibility with the people".

Yet the men in Pinkerton's unit, the Second Battalion of the Fifth Cavalry Regiment, remain conflicted about the risks of joining forces with men who may have attacked them before. The New York Times quoted Master Sergeant Carlos Figueroa as saying some Volunteers reminded him of drug dealers who tried to go straight but always hedged their bets, adding: "These guys are never going to completely give up these ties".

The Americans are not arming Abu Azzam's men, who already have plenty of weapons. But they are set to begin training them, and hope to start paying about 500 of them $300 a month for guarding checkpoints and buildings, whether or not they are accepted into the Iraqi police.

During an awards ceremony recently, Pinkerton asked the 40 soldiers before him how many trusted the Volunteers. None raised a hand. That is the correct way to think, he told his men, urging them to "stay focused". Later, First Lieutenant Tom Cherepko said: "We fully understand that maybe a few months ago they were attacking us. We don't trust them, but we'll work with them. That's my way of not having to come back for a third rotation, getting them to stand up for themselves".

On a recent morning in Nasr Wa-Salam, Abu Azzam was holding court in his office. He sat cross-legged on an upholstered chair in front of a rickety window-mounted air-conditioner, fingering light-blue prayer beads. A procession of shaiks filed through for private talks. Later, he said his men joined forces with the Americans because the Neo-Salafis were killing so many fellow Sunni Arabs. But he allowed that the new alliance was complicated, saying the Americans will someday leave and the far bigger threat is a permanent Iranian occupation.

Abu Azzam fears the Muthanna Brigade is a harbinger of that, because he says it is infiltrated by Iranian-sympathising militiamen who abuse Sunnis. He became cagey when questions turned to his activities after the US invasion in 2003, saying: "I was among the people who refused the occupation". But he insisted that he never attacked Americans.

Abu Azzam listed the insurgent groups he knew, including the 1920s Revolutionary Brigade, the Islamic Army, and Jaysh Ansar al-Sunna - a Neo-Salafi faction known for gruesome beheadings. He said: "All of them I am in touch with. They are waiting to see if my experience will succeed. If it succeeds, they will adopt it. But if it doesn't, it will cause confrontation".

The paper said: "Nassir, 6-foot-3 and broad-shouldered, is as crisp in his dress as his bearing. He has thrived in the military even though he is a Sunni Arab from Hit, deep in Anbar Province. US commanders believe that some aides to the Shi'ite Prime Minister...Maliki have systematically driven out Sunni and moderate Shi'ite army commanders to make way for more sectarian leaders. But Nassir commands a predominantly Shi'ite unit. Pictures of him shaking hands with Maliki hang in his office. Nassir denies harming Abu Azzam's movement and says he just follows orders".

The New York Times quoted Nassir as saying: "Any civilian who stands up in the street and carries his weapon without an official order, I will detain him". He was referring to orders from Iraqi superiors. Abu Azzam's men in the US sector have been carrying weapons and standing guard for months with the explicit approval of American officers. Nassir denied that his men pursued sectarian goals, saying: "This is a very silly question from Abu Azzam". The general said he hated militias and that there was no way for Abu Azzam to know whether his men were part of them. He suggested that the Volunteers' new loyalties were not genuine, saying: "Every day they put on a new hat".

Pinkerton had asked his bosses to find a way to replace the Muthanna Brigade with another Iraqi force, perhaps the Kurdish-commanded army unit which patrolled west of Nasr Wa-Salam and had good relations with Abu Azzam's men. Still, he acknowledged that Nassir was "a lot more competent than most Iraqi officers", adding: "I really believe that under the right leadership he could be a great officer. I think he's getting some bad guidance from above. Maybe he's not dirty. Maybe he's that loyal".