BAGHDAD, Iraq -- The plan was simple: Iraqi troops would block escape routes while U.S. soldiers searched for weapons house-by-house. But the Iraqi troops didn't show up on time.
When they finally did appear, the Iraqis ignored U.S. orders and let dozens of cars pass through checkpoints in eastern Baghdad -- including an ambulance full of armed militiamen, American soldiers said in recent interviews.
It wasn't an isolated incident, they added.
Senior U.S. commanders have hailed the performance of Iraqi troops in the crackdown on militias and insurgents in Baghdad. But some U.S. soldiers say the Iraqis serving alongside them are among the worst they've ever seen -- seeming more loyal to militias than the government.
That raises doubts whether the Iraqis can maintain order once the security operation is over and the Americans have left. It also raises broader questions about the training, reliability and loyalty of Iraqi troops -- who must be competent, U.S. officials say, before America can begin pulling out of Iraq.
Last week, for example, Sgt. 1st Class Eric Sheehan could barely contain his frustration when he discovered that barriers and concertina wire that were supposed to bolster defensive positions had been dragged away -- again -- under the noses of nearby Iraqi soldiers.
"(I) suggest we fire these IAs and get them out of the way," Sheehan, of Jennerstown, Pa., reported to senior officers, referring to Iraqi army troops. "There's nothing we can do," came the reply.
U.S. soldiers from the 4th Squadron, 14th Cavalry Regiment eventually blocked the road again while Iraqi troops watched from a distance.
Some Americans speculated the missing barriers were dragged off to strengthen militia defenses in nearby Sadr City, a sprawling Shiite neighborhood that is a stronghold of anti-U.S. cleric Muqtada al-Sadr.
"They've been doing this all week. They're working against us," said Sheehan, who resorted to waking up the senior Iraqi officer at the checkpoint to complain -- futilely.
During another mission, Iraqi soldiers were suspected of looting the house of a wealthy resident, U.S. troops said.
Some Americans said they had seen much better Iraqi troops in the northern cities of Mosul and Tal Afar, which have more Kurdish soldiers. They have been disappointed by the performance of units committed to the Baghdad fight.
U.S. officers believe the problem has political and sectarian roots: Many of the Iraqi soldiers here are Shiites recruited from the Baghdad area.
As the security crackdown focuses on Shiite neighborhoods, Iraqi troops come in contact with fellow Shiites from some of the 23 known militias. That puts great stress on the soldiers, who grew up in a society where respect for religion runs far deeper than for government institutions.
"From my perspective, you can't make a distinction between Iraq army Shiites and the religious militias. You have a lot of soldiers and family members swayed and persuaded by the religious leadership," said Col. Greg Watt, who advises one of two Iraqi divisions in the city.
He then pointed to the nearby guards of an Iraqi army division commander.
"There's no doubt in my mind that he has soldiers who are followers of religious leaders," Watt said. "Are they loyal to the division commander? Yes. But they may be loyal to both."
Watt expressed confidence the Iraqi army could win if it came to a pitched battle with militias.
"But what the Iraqi army can't do is protect soldiers when they go home, or protect their families," he added. "It's very, very difficult. That's why a solution has to be a political one and not a military one."
U.S. military leaders have repeatedly called on Iraqi Prime Minister Nouri al-Maliki, a Shiite, to aggressively disband the predominantly Shiite militias, but so far little progress is seen on Baghdad's streets.
Most if not all the Shiite militias have ties to the government. Most prominent is the Mahdi Army militia led by al-Sadr, who controls 30 of the 275 parliament seats and five Cabinet posts.
"All the militias we have are represented in parliament and government. We hope they're going to try to find a solution between themselves," said Maj. Gen. Abid Amir Rasheed, commander of the Iraqi army's 6th Division.
One immediate solution would be to bring in more units from outside Baghdad. Although many of those units are largely Shiite, too, the soldiers would be less likely to have family living under militia control.
But many Iraqi troops refuse to serve away from home. The commander of U.S. forces in Baghdad, Maj. Gen. James Thurman, said his requests for 3,000 more Iraqi soldiers have been refused because the troops won't leave their home areas.
That attitude frustrates American soldiers.
"They have to step up, make sacrifices. We've made thousands of sacrifices for our own country's freedom," said Staff Sgt. Jeremy Chinnis, 30, of Richmond, Va. "I think they think the Iraqi people don't support them."