Recent attacks on fighters in Iraq's Sunni Sahwa militia could drive some back into insurgency despite the militia playing a key role in reducing violence across Iraq since 2006, its leaders have told Newsnight's Gabriel Gatehouse.
Khalid Khodeir is short and round and his smile is eager to please. His banter is that of any second-hand car salesman anywhere in the world. As he took me round his showroom on the outskirts of the city of Baquba, he seemed an unlikely militia leader.
But when he is not flogging used cars, Khalid Khodeir is in charge of nearly 8,000 armed men.
He is the local Sahwa leader. The Sahwa - the word means awakening - is a Sunni militia force. Many of its members are former insurgents.
Baquba is the capital of Iraq's eastern Diyala province. It is still one of the country's most unstable regions - a melting point of different militias and insurgent groups where sectarian tensions can run high. Bombings and shootings are a daily occurrence.
As well as al-Qaeda, we're targeted by certain political parties, foreign terrorist groups, as well as the militias
Khalid Khodeir Militia leader
But the buildings pockmarked with bullet scars bear testament to an even more troubling past.
In the chaotic aftermath of the 2003 invasion, parts of Iraq came under the control of al-Qaeda. Initially they received support from much of the local population - in Sunni neighbourhoods in the capital, in Anbar province to the west, as well as Diyala to the east.
Al-Qaeda and local insurgents fought side by side against the invading forces, but when al-Qaeda started killing Iraqis as well as Americans that changed.
Local Sunni fighters turned against their former allies. They became the Sahwa, and they are credited with helping to turn the tide of the war.
Around 100,000-strong, they were initially paid by the Americans. But now the force is administered by the Shia-dominated Iraqi government and their loyalty is being tested.
Salaries are often not paid on time - if at all.
Khalid's men range from hardened veterans of the insurgency and the fight against al-Qaeda, to teenagers who are not even old enough to vote in Iraq's new democracy, but who have been handling Kalashnikov rifles for several years already.
Today these fighters live in fear of assassination. Khalid's predecessor was murdered, killed by a suicide bomber at a reconciliation conference.
"We are targeted by different sides," Khalid said. "As well as al-Qaeda, we're targeted by certain political parties, foreign terrorist groups, as well as the militias."
Iraq's former prime minister Iyad Allawi fears the Sahwa could return to fighting
This is not mere paranoia. In just one incident in July, a suicide bomber killed more than 40 people as Sahwa members were queuing up to receive their salaries. The attack was claimed by al-Qaeda.
Iraq's political stalemate is making matters more tense. It is more than five months since a general election returned a hung parliament.
Khalid and his men complain about what they say is a campaign of intimidation and arrest by certain elements in the current caretaker government who they believe are intent on dismantling their movement.
"The Sahwa is capable of fighting its enemy face to face, but if the enemy comes with an official uniform - in a government uniform - then, of course, you can't overcome him," Khalid said.
If Khalid is anything to go by, the mood of the Sahwa is defiant.
"If I am arrested," he said, "a thousand more like me would emerge. Even if I am killed, a thousand more like me would come forward."
In the election in March, Sunni voters generally and Sahwa members in particular overwhelming backed the former prime minister, Iyad Allawi.
But with political factions still deadlocked over a power-sharing agreement, it is far from clear what role - if any - he will have in the next government.
He says that if the pressure on the Sahwa does not let up there is a danger that these fighters could start slipping back into insurgency.
If we find one that we do not believe is still involved in the insurgency we will work very closely with the government of Iraq to get them released
Gen Raymond Odierno
"Of course they can and they will ultimately if their situation is not addressed. They can't be killed every day and be sitting like ducks waiting to be shot at. We have to do something urgently," Mr Allawi said.
Mr Allawi has a political interest in portraying himself as the man who can keep the Sahwa in line.
But even the US military - who were instrumental in setting up the movement in the first place - agree with Mr Allawi's assessment. However, they also agree with the Baghdad government, which believes that some of these militiamen never renounced the insurgency at all.
Speaking of the arrests of Sahwa members, Gen Raymond Odierno, the commander of US forces in Iraq, told Newsnight: "I think it's a combination of those who are still tied to the insurgency and those who should not be arrested.
"If we find one that we do not believe is still involved in the insurgency we will work very closely with the government of Iraq to get them released."
But the Americans are leaving. By the end of August they will end their combat mission in Iraq. By the end of next year they plan to withdraw all together.
The Sahwa have been promised jobs in the police and in the military, but so far little has happened.
Today the Sahwa find themselves caught between militants who want to kill them and a government that perhaps rightly does not trust them.
They say they want nothing more than to be accepted into the mainstream, but clearly they are still willing and able to fight to defend their interests.
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