Each day the 35-year-old man pulls open the metal shutter to his small sundry shop in Muqtadiya's Aruba shopping district, sets out some goods on the sidewalk and then waits – long hours, alone – hoping for customers who only appear at a rate of about 10 per day.

"It's been like this a long time now," he said. "There are no people shopping. I don't know why no one comes."

The reason is not hard to understand. Aruba is a victim of sectarian violence that wracked Muqtadiya after the fall of Saddam Hussein, and a stark legacy of al-Qaida in Iraq (AQI), which came to dominate the town until about six months ago when U.S. and Iraqi security forces drove them out into the nearby Diyala River Valley area known as the "bread basket."

With its Sunni populace, narrow winding side streets and alleys, and double-storied buildings just meters from expansive, dense palm groves for moving stealthily into and out of the city, the Aruba district was made the group's headquarters area. And its hundreds of shops and shoppers became ready sources of income for them.

"Anybody going to the market in Aruba could be stopped and asked for money," said Hugo, an Iraqi interpreter for U.S. troops who lived in Muqtadiya. Shop owners had to regularly pay "feadea" – extortion.

(Hugo, like other interpreters for coalition forces, uses a pseudonym and wears a mask when in public to avoid recognition and retribution against his family by insurgent supporters.)

Hugo said Muqtadiya – with a population of 100,000 including surrounding villages, down by half – was a bustling but quiet trading town of mixed Sunni and Shiite residents until 2004, when Sunnis fleeing coalition and insurgent gun battles in Fallujah began flooding the city. With them also came the gunmen, al-Qaida among them. Soon Shiite militias formed to protect co-religionists and the battle lines were drawn.

Sporadic clashes escalated, Shiites were pushed or fled from the neighborhoods they had shared with Sunnis and visa versa. When al-Qaida later destroyed the Shiite Husseineyah mosque the fighting escalated, with AQI spreading its control and harsh dictates over much of the western part of the city.

Iraqi security forces and coalition troops have driven most AQI from Muqtadiya, but at a cost. In Aruba's residential areas near the palm groves are scores of abandoned houses; in the traffic circle shopping precinct there's nary a wall without bullet holes. Partially burned out store fronts and piles of rubble are everywhere. What shops there are, are located inside the residential areas themselves – corner stores that have sprung up – to meet basic needs of people who avoid the commercial district.

"Only about 20 percent of the people who used to live in Aruba are still left," said U.S. Amy Lt. John Borders of Hawaii. "And those who are left are afraid of AQI suicide vest bombers [who infiltrate the city] so they stay close to home."

Lt. Casey Campbell, who leads another U.S. army company that patrols Muqtadiya added another reason. Over the years many shops were looted and owners who would want to reopen would have to not only buy new stock but also pay to repair their former premises, gambling that business would eventually return. It's cheaper to open for business elsewhere, and many have.

In the Muleema district, for example, vendors line the main, crowded street, hawking everything from clothing to meat. Two AQI suicide bombings there in February have left people nervous – and very attentive to who is around them – but has not stopped people from going about their business.

Borders and Campbell are with the 3rd Squadron, 2nd Stryker Cavalry Regiment, and patrol the Aruba district regularly. Like other U.S. troops based near the city, they show coalition presence and to back up Iraqi soldiers and Iraqi Police. They also regularly check the neighborhood headquarters of the Sons of Iraq (SOI), the armed neighborhood watch group once called Concerned Local Citizens.

A part of those visits to SOI units is to check their duty rosters and ensure rules applying to carrying of weapons and duties are strictly followed. Of particular concern is SOI members not carrying those weapons off-duty and not patrolling beyond their own neighborhood checkpoints. The idea is to help keep the SOI members, whether in their own Shiite or Sunni neighborhoods or in mixed ones, from becoming a de facto militia.

The U.S. troops also keep a close eye on the Iraqi Police in Muqtadiya, who are mainly Shiite Muslims. Many of Muqtadiya's IPs, as they are called, are thought to be members of the Jaish al-Mahdi militia of Moqtada al-Sadr or to have links to the group or other Shiite militias.

Besides the danger of AQI sending suicide vest bombers into the city to terrify its citizens and destabilize what security achievements have been gained is the very real danger of IP members engaging in sectarian-motivated crime or crime that would feed sectarianism.

U.S. officials say there have been a number of incidents of Sunnis on nearby highways being kidnapped and held for ransom, and in some cases IP members are believed to have been involved.

"What we are seeing now from the insurgent security point of view is cleaning up sectarian behavior in the police," said Lt. Col. Rod Coffey, commander of the Stryer Squadron. "If that were to get out of hand, Muqtadiya could end up with people saying, 'we'd better arm ourselves again.'"