The still night air is shattered by the deep thump of an exploding rocket-propelled grenade. For the six soldiers with Apache Company, 1st battalion 34th Armor regiment staked out on the roof of a derelict building beside the Khaldiyah river bridge, the elusive "RPG guy" has struck again.
"Let's go. Move," orders Sgt. Spencer Hill, from Bremerton, Wash. A Bradley Fighting Vehicle clatters down the highway, halting briefly to pick up the soldiers.
Moments later, as the Bradley approaches the scene of the RPG attack in the center of this ramshackle town, the intercom crackles, "There are two people running down the alley. Go get them."
The Bradley lurches to a stop, the rear ramp is lowered and the soldiers spill out. They move swiftly but cautiously down the gloomy alley, guns raised, eyes scanning the shadow- dappled houses on either side.
Hours earlier, soldiers from Apache Company were patrolling the same dusty streets, handing out copies of "Freedom," the coalition's Arabic-language magazine, smiling and waving at passersby and listening sympathetically to the grumbles of local residents.
Combat troops one moment, peacekeepers the next - such is the complicated nature of soldiering in the Sunni triangle, the name given to the flatlands north and west of Baghdad that is the locus of the Iraqi insurgency.
"After we get shot at the night before, we go out in the day handing out MREs [Army field rations known as Meals Ready to Eat], bottles of water, and pens," says Capt. Ben Miller, from Marshalltown, Iowa, Apache Company's commander. "It's hard, but I guess that's what we get paid for."
And it appears to be working. Attacks have declined considerably since the 800-strong battalion arrived in Iraq in September and settled into the old British air base at Habbaniyeh on the eastern edge of Khaldiyah.
"When we arrived we couldn't leave the base without getting shot at," says Lieut. Lonnie Moore, from Wichita Falls, Kansas. "They were hitting us 15 to 20 times a day. Now it's more like one attack a day."
Better training and weapons ensure that US troops generally gain the upper hand in a head on clash with insurgents, all of whom are locals, Miller says.
"The claim that foreigners are involved is bull, at least in Khaldiyah," he says. Improvements in intelligence-gathering - key to a successful counter-insurgency campaign - has also helped.
"John," the battalion's Arabic-speaking intelligence officer, stands in the open hatch of a M-113 armored personnel carrier (APC) as it trundles along a dusty country road, passing green fields, ditches, and palm tree plantations.
The APC is accompanied by a Bradley and an M1 Abrams tank, the gun barrel of which swings menacingly from side to side.
Sitting inside the APC is a detainee arrested days earlier who agreed during interrogation to point out the homes of several insurgents. He wears a military jacket and floppy hat; his face is hidden by sunglasses and a scarf.
But the prisoner seems hesitant to identify the houses, incurring John's anger. Having passed the house of one suspect, John scolds the prisoner in Arabic and slaps him lightly on the mouth.
"Why didn't you say when we passed the house?" he asks angrily. The detainee shrugs his shoulders apologetically and mumbles excuses.
The armored convoy pulls over and the soldiers emerge to begin a patrol of a side track. Children run up, their hands outstretched. "Give me, give me," they clamor in English, pointing at watches, pens, cameras, and any other potential gift.
One youngster who has a cut in his scalp has his head bandaged by a medic while other soldiers hand out MREs and bottles of water.
The soldiers scout one of the buildings indicated by the detainee. The map coordinates are recorded and the patrol moves on.
"We'll give them a couple of days to think we're not coming back. Then we'll return at night. We usually catch them asleep in bed," Miller says.
It's the hottest day of the year so far. The soldiers sweat beneath their heavy flak jackets, burdened by weapons and equipment. More children come out. The youngsters laugh in delight when Miller joins them in an impromptu game of soccer.
"You like us now, but wait until we come back and arrest your brothers," mutters one soldier.
Further down the remote dirt track, residents stay by their homes, apparently reluctant to approach the patrol. Miller's alarm bells begin ringing and he orders the soldiers to return to the main road.
"It was getting kind of eerie out there," he says later. "After a while, you tend to pick up on these things."
The return journey to the base takes the three-vehicle convoy through Khaldiyah. The median running down the center of the highway in the town is often planted with roadside bombs, usually artillery shells encased in concrete to resemble curbstones.
Miller's Abrams tank grinds slowly between the median and the APC, crushing several suspiciously loose concrete blocks, its massive bulk affording protection to the smaller vehicle in case one of them turns out to be a bomb.
The battalion recently contracted a local builder to fill in the median with cement to prevent insurgents burying the bombs in the dirt. However, the Americans discovered that the road laborers had been hired by local insurgents to plant bombs in the fresh cement for later detonation. The 12 workers were arrested and the planted bombs dismantled.
The battalion is midway through its yearlong tour and the soldiers look for ward to returning home. For many of them, the hardest task is being mobbed by dozens of wide-eyed and noisy children while patrolling Khaldiyah. This is when the language and culture gap becomes most apparent.
"They drive me insane in the city," Lieutenant Moore says. "The kids surround you, saying 'Gimme, gimme.' " But the reception is generally cordial.
"The worst we have is people refusing to shake our hands, but that's OK," Lieutenant Moore says. "We tell them that the sooner they stop shooting at us, the sooner we can go home to our families and they can rebuild their country."
The full moon bathes the countryside in a ghostly silver light as the six soldiers lie hidden in the shadows of the derelict building outside Khaldiyah. The squad is on observation duty, monitoring the neighborhood for an insurgent known as "RPG guy" who has a habit of firing a rocket at US troops every other day.
Other than the distant bark of dogs and the buzz of insects, nothing stirs for nearly three hours. Then comes the blast from the RPG a few hundred yards up the road.
In the alley in Khaldiyah, the soldiers glance beneath parked cars for "RPG guy," and check around corners for possible gunmen.
"There's a guy in a white man-dress," one soldier calls out, referring to the full-length dishdash worn by Iraqi men. The patrol breaks into a sprint as two men dart into the entrance of a house, slamming the white metal gate behind them. Two hefty kicks and the gate springs open. Two soldiers cover the back of the building while others burst through the front door, rifles pointed before them. Out of one room come two men, three girls, and an older woman, looking dazed and frightened at the late-night intrusion. The two men are lined up against the wall. But the man in the white dishdash has disappeared.
"Man, it's like we're fighting ghosts," says Spec. Nick Moorehead from Harrisburg, Pa.
Three men from a neighboring house are pulled into the road. One of them has a white dishdash. All three claim to be policemen, but their identification cards carry no names.
The Bradley, commanded by Sgt. Tyler Doughty from Newark, N.J., pulls up outside the house. As the soldiers interrogate the suspects via an interpreter, there is a second, closer RPG explosion, followed by the crackle of small-arms fire.
"Tight security, people," yells Sergeant Spencer as the Bradley roars off down the narrow alley to investigate, striking a parked vehicle and a wall in its haste.
"Shoot anybody coming through the back door," Sergeant Spencer orders, as the terrified old woman sobs on the floor.
The second RPG round was fired at a civilian truck but missed - apparently the insurgent mistook it for a military vehicle.
The Bradley returns, and three men from the neighboring house are handcuffed and pushed into the back. Two of them are positively identified by the police at the nearby station and released. The third man, whose plea of innocence fails to impress the soldiers, is taken back to the camp for interrogation.
The incident emphasizes the difficulties faced by US troops confronting a low-grade guerrilla war. Any goodwill gained during the day through giving out food and water, and the friendly approach of the US soldiers stands to be lost at night when troops are forced to react to an attack.
"It's difficult," says Sergeant Doughty. "We see people running away after an attack and we can't tell if they are the guys that did it or someone just getting out of the way. That's the hard part of what we do. But we still have to check it out."