The troops call it Route Barracuda, a patch of terrorist territory in the northern Iraqi town of Tall 'Afar, where thousands of U.S. and Iraqi forces have converged for the biggest battle in nearly a year. On this sweaty September afternoon, the neighborhood is living up to its name. A squad of U.S. commandos enters an abandoned house and clambers up to the roof. The 2-foot lip doesn't give much cover from the bullets raining down on them from insurgent gunmen firing from a building 200 yards to the north. Rounds flying at supersonic speed crack inches from the troops' ears. "Get down, goddammit," a Green Beret hollers to his Iraqi counterparts. On their bellies, two weapons sergeants start loading an 84-mm M-3 antitank recoilless rifle. "They got guns," says a commando shouldering a rocket launcher. "Let's f_______ do this." He kneels, exposing himself without any choice, takes aim and fires. Whump. The top of the insurgents' building blossoms black smoke. Over the cacophony of machine-gun fire and explosions, the leader of the commando team bellows to his men that the insurgents have spotted them. "Displace, displace--they got our position!" he yells, as the troops vacate the open rooftop in a stooped sprint.

The offensive in Tall 'Afar, which wound down last week, was this year's Fallujah--a mass assault involving 7,000 U.S. and Iraqi soldiers and hundreds of Bradleys, battle tanks, artillery pieces, all combined with AC-130 Spectre gunships, F-16 fighter jets and attack helicopters. Unlike the Fallujah battle, Tall 'Afar raged mostly unseen, with accounts of the fighting limited largely to the reports of U.S. and Iraqi officials in Baghdad, who declared that the onslaught had succeeded in driving out the bands of rebels--local units commanded by al-Qaeda kingpin Abu Mousab al-Zarqawi--from their latest safe haven. But almost as soon as the offensive ended, the cycle of mayhem started anew: two days after the capture of al-Qaeda's stronghold in Tall 'Afar, al-Zarqawi unleashed a retaliatory wave of 11 suicide bombings in Baghdad, killing more than 150 people in the deadliest day of attacks in the capital since the start of the war. Iraq's Defense Minister, Sadoun Dulaimi, responded to the attacks by telling reporters, "I think what is happening is the last breath of the terrorists"--an assessment that even some U.S. commanders found unduly upbeat after yet another bloody week. "We have not broken the back of the insurgency," says a high-ranking U.S. officer. "The insurgency is like a cell-phone system. You shut down one node, another somewhere else comes online to replace it."

Two and a half years since the U.S. invasion, nine months after the election of a government in Baghdad and weeks before millions of Iraqis will vote on a constitution that threatens to further split the country, this is the reality of the beleaguered U.S. mission in Iraq: a never-ending fight against a seemingly inexhaustible enemy emboldened by the U.S. presence, the measure of success as elusive as the insurgents themselves. For months, the intractability of the fighting and Iraq's momentum toward civil war have caused a gradual but still manageable erosion in public support for the Bush Administration's stick-it-out strategy, which depends on training Iraqis in sufficient numbers to take over combat duties and allow U.S. troops to begin pulling out. Senior U.S. officials say it could take a decade to quell the insurgency, with successful withdrawal years away. But the devastation caused by Hurricane Katrina and the massive price tag for rebuilding the Gulf Coast have ratcheted up the sense of urgency among lawmakers and some Administration officials about finding an exit strategy. In a TIME poll taken 10 days after the hurricane, 57% said they disapproved of President Bush's handling of the war; 61% said they supported cutting Iraq spending to pay for hurricane relief. Pentagon spokesman Larry DiRita downplays those figures, asking, "What is it worth to avoid another 9/11?" But privately, Pentagon officials acknowledge that the reservoir of public faith in the war effort is running dangerously low. "The issue of American staying power is forefront in our minds," says a military officer. "Everything has costs."

With the public increasingly unwilling to pay those costs, the U.S. faces hard questions. Can political success still be salvaged from an unwinnable military fight after the series of failures (see following story) that have marked the U.S. enterprise in Iraq? How can the U.S. extract itself without compounding the damage done to U.S. interests in the region? After a month in the al-Qaeda-dominated Syrian border region, TIME spent 10 days on the front lines of the war, having lived with U.S. and Iraqi troops as they prepared for the battle of Tall 'Afar, one of al-Zarqawi's biggest strongholds and, intelligence officers say, a place where he was detected in recent weeks. Waiting for the Americans were hundreds of hardened local fighters, small bands of foreign zealots and, in the notorious Sarai quarter of the city, a labyrinth of medieval alleyways laced with booby traps and roadside bombs. Two weeks after the start of the offensive, the military claimed more than 200 insurgents killed. But field commanders and top intelligence officers acknowledge that the U.S. is no closer to subduing the insurgents and the threat they pose to Iraq's stability. Although dozens of al-Zarqawi's fighters may have died in Tall 'Afar, the U.S. and Iraqi forces were unable to prevent others from getting away. In its tempo, ferocity and politically compromised outcome, the story of Tall 'Afar stands as a parable of the dangers, dilemmas and frustrations that still haunt the U.S. in Iraq. Despite the temporary tactical gains made by the U.S.'s 3rd Armored Cavalry Regiment, the battle refreshes doubts about whether anything resembling victory in this war can still be achieved.

Nestled close to Syria, Tall 'Afar is at the center of a vast border region rife with smuggling and anti-American sentiment. After the U.S. invasion, it became a gateway for foreign fighters entering Iraq. In time, homegrown insurgent cells came under the control of al-Zarqawi's al-Qaeda in Mesopotamia organization, which transformed the city into a training and command base for foreign jihadis and a hideout for al-Zarqawi and his deputies. After the fall of Fallujah, the town became a propaganda tool for the resistance, with attacks on U.S. forces in the city featured heavily in the "top 10 attacks" videos circulated among insurgent groups. For civilians, especially the Shi'ite minority, the city became a prison under insurgent rule. Al-Zarqawi's shock troops commandeered buses, schools and businesses for military purposes, evicting uncooperative families and selling their furniture. Insurgent videos and residents' accounts detail how anyone deemed to be collaborating with U.S. forces was executed, often publicly. "The enemy has taken good people who have worked with us out into the street and cut their heads off," armored reconnaissance troop commander Captain Jesse Sellars told his replacements coming into western Tall 'Afar.

Although U.S. officers had known for months about the atrocities taking place in Tall 'Afar, they were powerless to do anything about them. Stretched thin fighting rebels in places like al-Qaim and Mosul, the military dedicated just a single infantry battalion to an area twice the size of Connecticut. In May, however, more than 4,000 troops of the 3rd Armored Cavalry Regiment, a unit with a unique combination of tanks, Bradleys and helicopters that is back for its second tour in Iraq, were hastily rerouted from the south to the Tall 'Afar region, where they began disrupting the insurgents' supply lines and safe havens. They paid a price: two platoons alone saw a third of their 50-odd soldiers killed or wounded in less than four months, and hardy Abrams tanks and Bradley vehicles burned in the streets. "A day can go from good to bad in a heartbeat in there," says reconnaissance helicopter pilot Captain Matthew Junko. And so last month the regiment's commander, Colonel H.R. McMaster, told his troops what he had been itching to say all along: it was time to take back Tall 'Afar.

The order for the main force to move comes on Sept. 2. That day, in an armored squadron pushing into the city from the north and the south, Grim Troop's Blue Platoon, dubbed the Dragoons, enters from the southeast along an artery code-named Route Corvette, into a predominantly Shi'ite neighborhood. Within 30 minutes, they come under sniper fire. A three-man sniper team from the élite Iraqi Counterterrorism Task Force (akin to the U.S. Delta Force), with a pair of U.S. special-forces liaisons, takes positions in front of the platoon, scanning for muzzle flashes, as an Abrams tank 50 yards up Corvette fires its 120-mm cannon at an insurgent mortar team, followed by a burst of .50-cal. machine-gun fire. A helicopter swoops ahead, firing a Hellfire missile at the insurgent position to help clear Blue Platoon's path. The helicopters kill at least a dozen insurgents by firing missiles into safe houses. At day's end Blue Platoon pulls out of the city to a rendezvous point in the desert, but fresh intelligence suggests the insurgents are displaying their mettle and have fallen back into well-defended positions. This enemy is not a rabble.

The Dragoons re-enter Tall 'Afar at 6 a.m. the next day, linking up with two Iraqi army infantry companies of Kurdish peshmerga and the U.S. special-force teams attached to them. The mission is to begin "draining the pond," as U.S. officers call it--clearing civilians from what is about to become a battlefield so that the insurgents could not blend back into the fold. The scenes are heart wrenching: the Kurds burst into houses as families gather for breakfast, ordering them at gunpoint onto the street with only the possessions and provisions they can grab in a few seconds. Women wail, and children cling to their mothers' sides, as they head to temporary camps on the city's fringe. Although explosions can be heard in the distance, the town takes on an eerie silence. "The city has never been this quiet," says a U.S. special-forces officer. "They're either getting ready, or they've left." Captain Brian Oman, the leader of the Dragoons, wonders if the homegrown "bad guys" are going to put down their weapons and sneak out with the civilians. "We'll be fighting them again in a week," he says.

It doesn't take that long. In the morning, the U.S. and Kurdish special forces begin moving north, toward Sarai, through the stone-paved alleyways. Within minutes, they are ambushed. The U.S. commanders rush machine-gun teams to the rooftops to pour out suppressing fire as the others advance below, clearing houses as they go. Anguished families come rushing out, caught in the cross fire and herded by the soldiers to the relative safety of the edge of town. A little girl cups her ears with her hands and wails each time firing breaks out. A 5-year-old boy gingerly waves a white flag. Insurgents duck and weave across housetops a few blocks away, trading fire as they withdraw back into their nest in the Sarai neighborhood.

The Green Berets pursue them onto Route Barracuda. Fire fights rage from one side of the street to the other, the combatants as close as 55 yards apart. Bradleys from Red Platoon pull forward, pounding the enemy firing positions; then the insurgents shift buildings and fire from new locations. Only after an Apache attack helicopter sends missiles into two insurgent buildings does the firing stop.

But the next day begins with a blistering fire fight. With the insurgents sniping at the soldiers on the front lines, the U.S. troops blast the area with cannon fire, obliterating nearby shops and houses from where gunmen had been shooting just moments before. The fighting is so close, you could throw rocks and hit the man trying to kill you. Buildings erupt in smoke and flames. F-16 fighter jets roar overhead. "We got people moving around on rooftops in the vicinity of the mosque," the Green Beret team sergeant reports on radio. Six Hellfire missiles come barreling in, detonating 80 yards away and showering rubble onto the troops' helmets. Pulling out, the Renegade Troop Apache pilot calls merrily to the team sergeant on the ground, "Stay safe, and kill some bad guys."

The insurgents withdraw, only to resurface in a flanking movement from the west, trying to snipe at Green Berets looking to the east, sparking another long fire fight. When things quiet down, it isn't for long. Although the U.S. inflicts heavy punishment on al-Zarqawi's men, the Americans also absorb losses. During a raid by Delta Force operators of Task Force 145 in western Tall 'Afar, insurgents put up fierce resistance at a house believed to be sheltering one of the city's top al-Qaeda operatives. Eight Delta men are wounded, two so seriously that an AC-130 Spectre gunship has to give a medevac covering fire to get the wounded to a combat-hospital operating theater in time to save them. Elsewhere, an improvised explosive device detonates under a Bradley fighting vehicle, blowing off its lid and killing a young medic who, though based in the rear, had volunteered to enter the fighting fray. A few feet forward, the toll would have been worse, killing the Bradley commander and his gunner. "This is a war of inches," says a shaken U.S. officer.

Across Iraq, the prize for the U.S. remains a clear-cut outcome, some indication that the U.S. is doing anything more than playing whack-a-mole with the insurgents. In Tall 'Afar, the U.S. and Iraqi troops awake on the morning of Sept. 6 to the sound of messages being broadcast over loudspeakers instructing civilians to leave. At mid-morning, families begin to emerge across Route Barracuda waving sad little white flags. As a family shuffles past, a Green Beret weapons sergeant bellows for them to be stopped. "Who's that red-headed guy?" he asks. The men are sifted out, five identified as suspicious. Flashes of defiance and anger raise suspicions. "Hey, flex-cuff 'em," orders a Green Beret. Chemical swabs read positive for explosives on two of the men. Masked informants identify three--all brothers--as snipers, the other two as a rocket-propelled-grenade team. Across the battlefield, insurgents attempting to slip out of Sarai mix with civilians. Five dressed as women are snared, one with fake breasts. Others force children to hold their hands as though they are family. Some are caught; others are not. An intelligence officer says al-Qaeda is slipping to the east and behind them to the south, and "somehow--we don't know how"--cutting through the screen line to deploy to the west.

The two-day grace for civilians to evacuate stretches to a four-day standstill, as Iraqi Prime Minister Ibrahim al-Jafaari orders a tactical "pause." With his nation divided along sectarian lines over the Tall 'Afar operation, al-Jafaari insists on assurances from military commanders that the battle will be a decisive success. The wait leaves the troops embittered, their momentum lost to what they see as political calculations. "This is turning into a goat f___," bemoans an angry Green Beret. By the time al-Jaafari approves the dreaded assault into al-Qaeda's heartland, it fizzles. Not a hostile shot is fired, not a single enemy fighter is found. Safe houses and weapons caches are empty, cleansed like an operating room. Only one blackened corpse, left rotting for days, is found. "They've even removed their dead," said a Green Beret, not really believing it himself.

What did Tall 'Afar accomplish? At best, the picture is mixed. McMaster did succeed in driving the insurgents out, denying al-Qaeda its Tall 'Afar base and disrupting its networks. Intelligence picked up in Tall 'Afar led to the arrest last week of Abu Fatima, al-Qaeda's military emir in Mosul. The cost in U.S. lives was minimal: only four died in the two weeks of fighting since Sept. 2. At the same time, many of the insurgents who had holed up in the city got away because of the indecision of Iraqi political leaders. And while the Pentagon hailed the operation for displaying the improved mettle of the U.S.-backed Iraqi forces, the operation showed that deep sectarian and ethnic schisms still exist among the Iraqi troops. It's not hard to find commanders who fear they are training troops for a civil war. "I don't know if we're going to be able to prevent what's coming," says a front-line U.S. lieutenant colonel.

With the war wrapped into so many political knots in Baghdad and Washington and the insurgents proving so resilient, the fight in Tall 'Afar, as in Iraq, is far from over. On the ground in the deserted city, the U.S. is pouring money into reconstruction in a bid to win local opinion. But there is every reason to believe the violence will return and the U.S. will be forced to fight there again--with the insurgents betting that the Americans will lose a bit more of their will and support each time they go back. In a house overrun during the battle, a newspaper sits in a living room, its pages brimming with pictures of a U.S. assault in the city. Dated Sept. 2-10, the report could have been an account of this month's battle, but it isn't. It is already a year old. --With reporting by Sally B. Donnelly/Washington

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