Baghdad: They were strangers in a strange land: the American soldier in Iraq and the Sunni army captain in a Shiite neighbourhood.

The Iraqi intelligence officer had recently arrived in east Baghdad with his unit from outside Fallujah. The American platoon leader had come to Iraq months before, but now as the US was building up its troops, he found himself with a new mission to protect the people of the Zaphraniya neighbourhood.

Both men were just starting to understand Zaphraniya. What they did not know was whether they could trust each other.

But Iraqi army Capt. Ali Hussain offered US Army Lt. Clay Hanna a chance to meet with the most important asset an intelligence officer has: a source.

The gamble worked. Hanna and his platoon used the information Hussain's source provided, along with their own intelligence, to capture eight local members of the Mahdi army, the Shiite militia that has become US forces' prime enemy in east Baghdad.

When the US launched its new counterinsurgency strategy in Baghdad at the beginning of the year, this was how it was supposed to work: Iraqis and Americans working together to develop the kind of street-level intelligence needed to go after the militias and insurgents in Iraqi neighbourhoods.

Hanna's partnership with Hussain shows the potential of the strategy in the hands of bright, creative and motivated troops. But his experience also signals how difficult it will be for the United States to build on those small victories.

Baghdad, with its mix of ethnicities, political parties and weak traditional leaders, may well be the most complex counterinsurgency the US has faced. And the Mahdi militia, led by radical cleric Moqtada Al Sadr, is a far more influential enemy than the insurgents who have been the focus of US efforts in years past.

Cornerstone of success

And, at the height of Hanna and Hussain's success in chasing down the Mahdi militia in Zaphraniya, Al Sadr loyalists at the top of the Iraqi government would make their move.

One cornerstone of Hanna's success is his ability to assess with just a look whether an Iraqi is the type who might help him out with a tidbit. Then he patiently works to make that Iraqi his friend.

"This is a platoon leader's war," said Lt. Andrew Aiken, the intelligence officer for Hanna's headquarters who introduced Hanna and Hussain. "To be successful you have to be clever, you have to take the initiative, and above all you have to be patient. Lt. Hanna has done just that."

The breakthrough in Hanna and Hussain's relationship came on the soccer field. When, after a day of talking, a soccer game was proposed, Hanna made sure he and Hussain ended up on the same team.

In the days after the game, Hanna began offering Hussain the support of his platoon for any raids the Iraqis were planning.

"I would continue to bring this up every time he mentioned bad guys he was tracking,'" Hanna said. "One day he told me that he was bringing in a source that knew exact locations of several important [militia] fighters."

The eight Mahdi army members netted in the raid included several cell leaders and men who had planted roadside bombs. After a celebratory feast, Hanna (29) and Hussain began sharing information regularly.

Hussain found that his bosses at the brigade and division above him, many of them Shiite, were hesitant to go after some of the targets he had evidence against. But the Americans did not share that reluctance and wanted to dismantle the Mahdi army from the ground up.

"He feels, to go about his job, he can't go through his higher headquarters," Hanna said. But Hanna remains hopeful that despite the obstacles, he and Hossein will continue to be able to round up the militia members in Zaphraniya. "I want," he said, "to win this fight."

- Los Angeles Times-Washington Post News Service