Mr Ahmed, 60, who goes by the name Abu Hiba, used to be a football coach and sports club manager. Now he is in charge of 51 militiamen in the Diyala river valley – a detachment of the Sons of Iraq, the Sunni militia set up and paid for by the US military to kill or capture al-Qaeda militants.

General David Petraeus, the US commander who oversaw President Bush’s troop surge strategy, has been given much of the credit for quelling the violence in Iraq. As far as Abu Hiba is concerned, however, he and his men are responsible for peace in Diyala. “You couldn’t even come to this area if it wasn’t for us, the Sons of Iraq,” he told The Times.

It is a grand claim, but not one that is disputed by the US military. Until yesterday America paid and advised the 99,000 Sons of Iraq – members of what is also known as the Sunni Awakening. According to US officials, as many as 95 per cent of the Sons of Iraq have been involved in al-Qaeda and a large number fought against US troops, giving the militia an invaluable insight into how the enemy operates.

Their familiarity with the methods, hideouts and key players of al-Qaeda puts the group at odds with the Shia-dominated Government however, which today is supposed to begin paying and integrating the force into the police, army and Government.

The Americans may be happy to forgive and forget their insurgent past, but the Shia-dominated Iraqi regime is less willing to turn a blind eye to the largely Sunni force, which it holds responsible for the sectarian violence that nearly caused a civil war.

The group has, however, been remarkably successful. According to US intelligence, in the six months that it has been operating, Abu Hiba’s group has helped to kill at least 35 al-Qaeda fighters, losing ten of their own men in the same period. Undoubtedly, the improved security is also due to the increased aggressiveness of US troops from the 2nd Stryker Cavalry Regiment, who arrived in May, but the Sunni Awakening has played a big part. In and around Mukhisa, 40 Americans have been killed in the past two years, but only one since the Sons of Iraq have been operating.

In Diyala – a microcosm of Iraq and its problems, with a mixed Sunni, Shia and Kurdish population – the problem of what will happen if the militia are left in limbo is already becoming apparent. In the town of Waji-hiyah, a former al-Qaeda stronghold, 324 police positions recently became available. It was the hope of Lieuten-ant-Colonel Robert McAleer, the soldier in charge of the area, that Sons of Iraq would fill the vacancies. Instead the Iraqi police gave the jobs to Shia Muslims from outside the town.

“We don’t know if it was cronyism or a sectarian action . . . but there is no greater source of anger – which could push the Sons of Iraq towards al-Qaeda – than the Government failing to show they are fair,” Lieutenant-Colonel McAleer told The Times.

The Sunni fighters are eager to take positions in the official security services, where life is more secure and pay, conditions and equipment are better. The starting salary for a police officer is $470 (£261) a month, while a Son of Iraq gets $300, though most take home between $130 and $150. The police also receive life insurance.

Senior US military sources said that America would pay the salaries of any members of the force who did not find alternative employment. “It is a cheap price to pay in the interests of peace in Iraq,” one officer said.

Jalaluddin Al-Sagheer, a Shia MP of the United Iraqi Alliance, said that the Sons of Iraq were no more than a temporary measure. “It is believed that the situation which required the Sahwas [Sons of Iraq] to be formed has now, to a large extent, gone,” he added.

For many of the Sons of Iraq all they have ever known is military life.

Shakir Naji, 38, was a captain in the Iraqi army during the invasion of 2003. “If they stop the Sons of Iraq and don’t let me rejoin the army, who knows what I will do?” he said. The US military hopes the group will be incorporated into the security services. General Ray Odierno. coalition commander, is aware of the consequences if this does not happen: 99,000 armed, trained and unemployed men on the loose – rich pickings for an insurgency considered to be on the ropes.

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