At dawn, the sky over Baghdad turns red for a few minutes before sunlight breaks through the dust. Combat engineers have been clearing IEDs from the streets of Amiriyah since 3 a.m., but the 500 American soldiers about to descend on the western Baghdad neighborhood wait for the sun. Just as it rises, Apache helicopter gunships arrive overhead, and, in the blinding light above them, two F-15 attack aircraft begin circling in a wide arc.

[...]

As a U.S. foot patrol navigates its way through garbage-filled alleys, the residents of Amiriyah, which has become a dumping ground for headless bodies, emerge from their houses to plead for the soldiers to stay. Without the Americans, they say, it's too dangerous even to take out their trash.

[...]

Gunners swivel their turrets as the column passes a corner lot strewn with junk and, eerily, a rusted Ferris wheel. A flare dropped from an Apache floats down beside it like a Roman candle. American soldiers have died in its shadow, and, tomorrow, an IED planted here will wound several more. Tonight, American snipers return under cover of darkness to the Ferris wheel, where, after a short wait, they kill two men planting more bombs.

[...]

As its sense of ownership grows deeper with each year it spends here, the Army has created its own universe in Iraq--an ecosystem with its own values, requirements, and purposes. The din of politicians speechifying about the war, the faux moral posturing of opinion-makers who claim to speak in the name of "the troops," everything that Iraq has come to represent in the American imagination--it all melts away in the 115-degree heat. What's left is the machinery of a war that, having been called into being by civilians, no longer bears a relation to anything they say.

[...] The anatomy of this universe, as much as anything that happens in it, points to an essential truth about the Iraq war: It has a momentum of its own. This much becomes clear even in Kuwait, where, at a desert air base, hundreds of soldiers line up in front of signs announcing flights to Speicher, Q-West, and other bases in Iraq. It is after midnight, but, from the other side of the base, the golden arches of McDonald's still glow in the sky. "When it gets built up like this, it's the surest sign you're going to lose," a contractor who served in Vietnam tells me, alluding to the wasted years that must elapse before this sort of infrastructure can come into being.

[...] Outside, hundreds of them idle in the noonday heat, their South Asian drivers sleeping in bullet-raked cabs. In convoys of 30, they will head north to the border, crossing near the Iraqi town of Safwan for the 400-mile run up Main Supply Route (MSR) Tampa to Baghdad. Safwan, whose residents welcome the trucks with volleys of rocks, offers a fitting portal into Iraq. In response, the military has contracted to build an entry point farther to the west, at a site called K Crossing, and a new highway through the Iraqi desert to go with it. Whatever guides the invisible hand behind all this, it isn't the logic of withdrawal.

[...] After flying from Kuwait to Baghdad, I head to Camp Liberty, where 1-10 Mtn's supply battalion prepares to head into the city with a load of concrete barriers for a checkpoint. The barriers come not from Kuwait but from the base itself, where the Americans have opened their own cement plant. Baghdad is rapidly disappearing behind a maze of blast walls, and the cement keeps coming: In the heat, men from the battalion clean the guns on their Humvees and swat away mosquitoes before delivering more of it.

[...] A Goodyear-sized blimp with instruments to monitor the area floats above it, tethered to Baghdad Airport. The blimp, an essential part of the Baghdad landscape, has had its share of problems. Army helicopters keep clipping its ground wire, and it once floated as far as the Iranian border, where U.S. forces shot it down.

[...]

Liberty was constructed on the grounds of one of Saddam Hussein's hunting preserves, and the base's most notable landmark, "Signal Hill"--a huge dirt rise with antennae and counter-fire radar at the top--was his shooting platform. Among the hunting aficionados here, word spreads whenever one of the dictator's imported African deer ambles by. He also stocked the man-made lakes from which Signal Hill was dredged, and, according to a contractor wearing a fly-fishing vest, Saddam chose fish poorly (carp won't respond to his lures). The lakes do serve a function, however. The Army just opened a water-bottling plant here, which can turn muck into half a million liters of drinkable water per day.

[...] Officers at Liberty estimate that, for every soldier who leaves the gate regularly, seven do not. At FOB Sykes, one who does, Sergeant Frank Lucciarini, says, "The guys in the city hate the guys on the FOB. It's two different mentalities: You have the war fighter and the people who say, 'I gotta play softball tomorrow.'"

[...] After the February bombing of the Shia mosque in Samarra, the number of U.S. patrols quadrupled in Baghdad. On a recent week, the Army sent 1,100 of them into the capital. It did so for a simple reason: Letting go has become the whole point of American policy, but officers know that, every time they let go of a sector, it comes apart at the seams.

The most important thing to understand about the way maneuver units fight the war is that no two of them fight the same way. 1-10 Mtn patrols constantly, but officers who served alongside it claim the National Guard brigade that preceded 1-10 Mtn rarely left the gate at all. Its sister brigade, 2-10 Mtn, which I visited last year, operated differently from both of them. The various operating styles derive, in part, from a philosophy of command in the Army that assigns nearly as much authority to the officer on the front line as the general back at division headquarters. Mostly, though, the brigades operate in a vacuum, with no strategy to guide them because no strategy has been offered.

[...] But the junior officers who patrol the streets daily will tell you that the most important condition--neighborhoods able to function without the Americans--won't be met for some time. The Iraqis who live there say the same thing. From the crumbling entryway to his house, a man in a tracksuit greets Snow. "We feel secure when we see the Americans," he says. "If you leave, every people here will kill each other." The patrol winds its way onto a block of large homes. On the porch of one, a middle-aged man named Nazar Al Jibouri introduces himself as a lawyer. He turns out to be a former Baathist, and, to judge by his palatial surroundings, the regime was good to him. None of this prevents him from submitting his own plea. "Until there is a correct army, the U.S. must not leave," he warns. "Or else we will have a disaster."

[...] After 1-10 Mtn returned, says Snow, "the violence tapered back to pre-Samarra levels." Views of the Americans changed, too--one of the metrics tracked by Iraqi pollsters who conduct opinion surveys for 1-10 Mtn. The percentage of residents who said they felt secure spiked from 25 percent to 57 percent, while 88 percent said they felt safest in the presence of U.S. forces. Hence the logic behind the unit's return: "If people don't feel secure, what do you do?" Snow asks. "You put forces back into Baghdad."

[...] Equal parts Lord Sauron and Dom DeLuise in a beard and white robes, the Sunni sheik can't stop laughing--about the fact that his wife, guessing he would be meeting with a female journalist, has gone on a jealous rampage upstairs; about the wisdom of Captain Jeremy Gwinn, a bright young officer who, having dealt with the sheik month after month, clearly doesn't believe a word he says; about the Shia, whom he insists account for a tiny minority of Iraq's population. And, when the conversation turns to the police, he keeps on laughing. "The good ones just take bribes," he says. "The bad ones rip off your head."

[...] Nor, with the exception of its senior leaders, does the officer corps seem that much more attuned to debates at home. The borders of the sectors where they work 20-hour days define their horizons. Even the brightest among them, explains one company commander, avoid broader discussions about the war--in many cases a conscious choice, he adds, for even to entertain doubts risks "taking a step into nowhere."

[...] The Army may have created its own universe in Iraq, but the outside world does intrude. [...] In the Pentagon's desire to hold up the deployment of additional brigades, he says, one may glimpse the future of the country the Army now calls home. There is none.