DIYALA PROVINCE // In the sparse communal living room of his family home, Omar is skilfully checking his assault rifle, his hands familiar with the shape and workings of the weapon as he lifts it to shoulder height and looks through the sights.
"If the Shia or the Mahdi Army come here to take revenge on us for things we never did, I'll hunt them like I hunt birds," he said.
Omar is 15 years old, and a Sunni. His comment about Shiites and the Mahdi Army, a powerful Shitte militia, draws smiles of agreement from three younger brothers, aged 13, 11 and 10, while his father, watching, nods.
They live in a small farming community, on the southern edge of Diyala province, where Iraq borders Iran. These sparsely populated hinterlands are also the point at which Sunni tribal areas butt against Shiite dominated territories in Wasit province to their south.
The rhythms of agricultural work, and the ebb and flow of murder, have dominated Omar's life since before he was 10 years old. The circle of violence shows no sign of being broken.
A low-level conflict - a complex mix of tribal and sectarian war - has been waged here for years, killings and counter killings grinding away at Sunnis and Shiites alike. In the last year and a half, 17 men from both sects have been murdered, according to local residents.
Shiite vigilantes have carried out raids into rural zones around Omar's home, killing Sunnis in vengeance for earlier Al Qaeda attacks against them.
The Shiites - also tribesmen, also farmers - blame their Sunni neighbours to the north of supporting Al Qaeda in the dark days of Iraq's civil war, and they say that support has never stopped.
Sunnis meanwhile insist the Mahdi Army, which fought against Al Qaeda, as well as Iraqi government and US forces, before being disbanded in 2008, is responsible for the killings. Like Al Qaeda, the Mahdi Army has been heavily implicated in sectarian bloodshed.
Abu Omar, Omar's father, admits that after the US-led invasion of 2003 he and other local Sunni farmers had backed Al Qaeda fighters who were killing Shiites in Wasit. "There was a sectarian war, Al Qaeda was here and they insisted we support them," he explained. "I was never involved in their murders, but I gave them money. That was the easiest way of getting them to leave my family alone.
"I knew they were attacking the Shiite families but how could we stop it," he said. "I feel bad that it happened and I know the Shia blame us and that is why they make these revenge attacks."
In rural Iraq it is common for households to have weapons, and boys often learn to shoot at an early age.
In Abu Omar's case however, that father-to-son transfer of field craft has gone beyond the usual target practice and bird hunting.
Abu Omar - he asked not to be fully identified - is a former sharpshooter in Saddam Hussein's elite Republican Guard.
As well as teaching his sons to fire rifles, he has taught them some basic infantry techniques, skills he believes could save their lives if Shiite gunmen find them in the open as they graze the family's goats.
With US forces set to withdraw or dramatically scale back by the end of the year, and with tribal Sahwa militia forces being dismantled, Abu Omar said villagers would have to rely on themselves for protection.
He predicted sectarian conflict would worsen in the coming months and in 2012, when US troops have left.
"We must be realistic," he said. "The Mahdi Army is returning and the [Iraqi] government is very sectarian against Sunnis so it will do nothing to help us. For that reason, we teach our children to defend themselves and to help us defend our homes." Abu Omar's village has seen little benefit from Iraq's experiment with democracy. Made up of about 100 simple houses, it has a school but no medical clinic, people scrape a living from the soil but have little to spare. A foreign NGO came in after the 2003 invasion and dug a well.
There is no permanent police presence in the area, and the nearest Iraqi army base is more than 10 kilometres away.
Close to the Iranian border, weapons are easily smuggled across the frontier. Police officials responsible for Diyala's southern zone admitted weapons smuggling was taking place but say the close-knit tribal networks prevent them from stopping it. "This problem is there," said one officer, who spoke on condition of anonymity because he was not authorised to talk to the media. "Villages are stocking up on weapons but we can never find them or catch the smugglers."
Officials in the area insist the conflict is more about tribal custom and traditions of revenge than a sectarian struggle, but some acknowledge there is a sectarian dimension.
Serhan, a shepherd in Abu Omar's village, said all residents were preparing for a bleak future.
"We expect the Mahdi Army will make a big attack this year and we will be ready for it," he said. "No one can really spare money to buy weapons but we must, if we don't have them we will all be killed."
As well as keeping a small flock of animals, Serhan smuggles guns from the frontier supplying them to his fellow Sunni villagers.
"Everyone is preparing for a big battle," he said. "We are certain it is coming, we just don't know when."