KEY POINTS:
As David Matsuda tells it, he's probably the last person you'd expect to see in a US military uniform climbing out of an armoured vehicle in Iraq.
An anthropology professor from California State University near San Francisco, he's a self-described peacenik who opposed the war in Iraq and
never carries a gun.
"I'm a liberal. I'm a Democrat," he says. "My impetus is to come here and help end this thing."
Dr Matsuda is part of the US military "Human Terrain Team" (HTT) programme, which embeds anthropologists with combat brigades in Iraq and Afghanistan in the hope of helping commanders in the field understand local cultures.
The programme is controversial: the American Anthropological Association has denounced it, saying it could lead to ethics being compromised, damage the profession's reputation and, worst of all, to research subjects becoming targets.
Dr Matsuda says the concern is based on a misunderstanding. "There's been a knee-jerk reaction in the anthropology community, that you've been co-opted, that you're a warmonger ... I came here to save lives, to make friends out of enemies."
Soldiers in northeast Baghdad - an area transformed in the past year from one of the most violent parts of Iraq to one of the best illustrations of the security improvements of late 2007 - are grateful for his expertise as they make the transition from fighting to peacemaking.
"It's a huge asset," said Staff Sergeant Dustin "Boogie" Brueggemann who, as a tactical psychological operations specialist, has spent the past year trying to win hearts and minds in Adhamiya, until a few months ago one of the most violent strongholds of Sunni Arab militants in Iraq.
"The guys who were out with him were saying: 'Dr Matsuda's so smart!' Soldiers even on the lowest level now, we see the big picture just by listening to him talk. He gave me so much information that had I known it a year ago I could have done things differently."
Dr Matsuda says he arrived at exactly the right time, when a sudden sharp decline in violence opened new opportunities for engagement.
The brigade is a classic example of last year's new US strategy in Iraq that saw greater numbers of troops deployed to Iraq and more emphasis on interaction with civilians.
In the past six months violence plummeted, as Sunni tribal leaders in the Adhamiya district turned against al Qaeda militants, and Moqtada al Sadr, the Shiite cleric whose Mehdi Army militia controls Sadr City, declared a ceasefire.
In December 2006, there were 450 killings in the area, mostly by sectarian death squads trying to drive rival groups out of their neighbourhoods. There were just 15 last month, mainly by ordinary criminals.
At the weekend, Dr Matsuda - in uniform but unarmed - spent two hours with soldiers from the 7th Cavalry lingering on a street in Adhamiya where a few months ago Americans would have had to fight their way in or out.
They meandered in and out of shops, bought falafel sandwiches and ate them on a street corner while playing with local children who already seemed to know their names. Periodically they knocked on doors and asked permission to come inside homes for a chat. They never turned down an offer of tea.
Dr Matsuda said he had learned a lot that day - about who was moving into vacant houses and who was renting them out, how a local clinic got its medicines, how shop owners were getting the money to reopen their stores.
"We have a window of opportunity here to make a difference for these people. We have to take it."
- REUTERS