Mixed emotions are written on Iraqi faces, as Sgt. Mindo Estrella leads a dusty foot patrol of US Marines in Fallujah. Smiles and furtive waves - even handshakes and shouts of "Good! Good!" - blend with angry, sullen stares.
One year after marines launched the most ferocious urban assault since the Vietnam War - emptying the city in order to root out entrenched insurgents - the Battle for Fallujah has yet to be won.
Last February, US commanders declared Fallujah the "safest" city in Iraq. Yet, despite a constant US and Iraqi military presence and the strictest security measures of any Iraqi city, insurgents have begun filtering back, and the prevailing calm veneer of a city on the mend can disappear in a flash. US forces here are often confronted with street-level decisions about how best to build the trust of residents while maintaining security - and their own safety. Though attacks are limited, roadside bombs are increasingly common; marines say teenagers are being paid to throw grenades.
Sergeant Estrella turns a final corner, just 50 meters from the base of Fox Company, and describes recent grenade attacks - one bounced off a marine's armored vest a couple of nights back, before going off.
"We have not been hit yet; maybe we are a hard target," Estrella, from Eire, Pa., says of his squad. "Or maybe it is not our time yet."
That was Saturday morning. A few hours later, at the same place, in darkness at the end of another patrol, Estrella was hit.
His squad passed a small knot of young men on a street corner, and someone hurled a grenade.
Estrella was struck with a dozen pieces of shrapnel. He has since been flown to a US military hospital in Germany and is expected to fully recover.
The plan in Fallujah is for the Iraqi Army to eventually withdraw, and then US forces, leaving security to budding Iraqi police units. But to those marines of the 2nd Battalion 6th Marines, the loss of the sergeant is another reminder of how dangerous the city remains.
When more than 10,000 US troops and several thousand Iraqis launched "Operation Phantom Fury" on Nov. 8 last year, marine top brass promised a "decisive victory" against "mugs, thugs, murderers, and terrorists" that controlled Fallujah.
Today, the sound of rebuilding is everywhere: the scrape of shovels lifting sand, the tap of trowel on brick, as Fallujans haul away mountains of rubble and rebuild, often from scratch. But there is also a tension that did not exist earlier this year, when only a trickle of residents had come home - and attacks were negligible.
The insurgency is persistent enough that marines on Monday morning launched a large operation with several hundred US and Iraqi troops against Zaidon and other nearby targets south of Fallujah, using helicopters to insert units. Officers believe Zaidon has been a base for training insurgents to infiltrate into Fallujah.
"The citizens of Fallujah, not the security forces, will have to decide if they want to keep the insurgency here or not," says Maj. Andrew Warren, the 2/6 battalion operations officer.
"I think they have made a decision, but there is a difference between deciding and acting," says Major Warren, from Charlottesville, Va. "When an IED [improvised explosive device] is placed on any one of these roads, they know about it.... They may not like it, and may not support it, but it's a whole new ballgame to turn him in."
After Estrella was hit with the grenade, marine units raided 60 nearby houses. Often clearly frightened, families were hustled into a single room during each house search. No one said they had heard or seen a thing. Young men and those with US dollars received the most questions.
US officers say they are not surprised that insurgent activity has increased with the return of an estimated 175,000 people - some 60 percent of the pre-war population - and the constant flow of construction materials into Fallujah.
"We haven't lost the city to insurgents," says Warren. "We've given it back to the people, and with that is some risk."
Marines speak with pleasant surprise at the lack of violence here during the Oct. 15 constitutional referendum. Under tight guard, Fallujah proved to be the most politically active city in all of insurgency-riddled Anbar Province, with a 93 percent turnout that accounted for more than half the ballots cast in the province. Voters roundly rejected the new constitution.
Unlike any other city in Iraq, Fallujah is sealed off, with six entry checkpoints; only residents are given identity cards that allow them to pass. The restrictions mean that insurgents can't draw upon an unlimited supply of recruits in the city, or easily replace discovered weapons caches.
But local tip-offs have been few.
"They don't like foreign armies in Fallujah," says resident Abdusalem al-Duleimi, referring to US and Iraqi forces. "The Iraqi Army here from the south, is no good." There is deep mistrust between Sunni Fallujans and Iraqi Army units, made up primarily of Shiites that control parts of the city.
Iraqi police in Fallujah have a different problem: Many are from Fallujah itself, and so are more vulnerable to intimidation.
"It's difficult to make a split with the bad guys, when your family is right there," says Capt. William Grube, the Fox Company commander. "Insurgents pay visits to people, and we can't be everywhere. They can't either, but it only has to happen one or two times for people to get the message."
"If we lose Fallujah, then we look like a bunch of yahoos who can't control one city. But we won't," says Captain Grube, from Emmaus, Pa. "It's a winnable war, if we make the right decisions."
Among those decisions is an "escalation of force" policy for stopping oncoming cars before using lethal force - an eight-step protocol meant to save lives of civilians, while still protecting them from car bombs.
Other decisions are made on the streets, too. As Estrella's morning patrol passed, a small boy showed a scratch on his knee. "If it were fresh, or bigger, I would have the doc look at it and clean it up - you know, the hearts and minds thing," said Estrella. "It works for some people. But there is still that 10 or 15 percent who want the insurgency, who want to hurt us."
If anything shows how US Marines in Fallujah view their "battlespace" one year after retaking the city, it is a speech this past weekend by Lt. Col. Scott Aiken, commanding officer of the 2nd Battalion 6th Marine Regiment, to his Fox Company.
Colonel Aiken, from Nashville, Tenn., had just awarded three Purple Hearts to wounded marines who had rejoined the unit. He thanked them for the calm that prevailed on Oct. 15 - when Iraqis voted to approve a constitution - and reminded them that violence can erupt "at the drop of a hat."
What follows are excerpts:
"You have taken numerous weapons caches off the street in the past week; some of you were involved in finding the 'Mother of all Caches' just down the road here - suicide vest [and] SA-7 surface-to-air missiles ... that made the airmen really, really happy.
"The insurgents have lost a [lot] of stuff, and I think they are going to have retribution towards us - it's something we need to be ready for, be alert for. But if we are lucky, they will tip their hand, and come into the open, and we get to [kill] them.
"Sometimes a guy says 'screw it, I am no longer an insurgent,' and at that point in time he becomes a part of society, and it is up to us to reinforce that, and keep that going. If you say, 'This guy was a Muj ten years ago, let's take him down and send him to Abu Ghraib,' [then] let's just take everyone to Abu Ghraib, because this place would just be an empty shell.
"I have to applaud you all. You are right now dealing with a tactical situation that none of your forefathers have ever dealt with. Your dad who fought in Vietnam never had to deal with 'escalation of force.' Your granddad, who fought in World War II, never had to deal with 'escalation of force.'
"They were never thrust into a sea of half-innocent people, with a few knuckleheads running around. They did not have to face a suicide vehicle-borne IED threat."