Most of the mud-brick stalls that line the street in this sweltering town on the Helmand River closed down a year ago when Taliban fighters began swaggering through the bazaar, levying taxes on merchants and seeding the roads with homemade bombs. Shopkeepers placed their wares behind padlocked tin doors, teachers shuttered the school, the doctor abandoned the health clinic and residents with means fled to other parts of southern Afghanistan. This town does not merit a dot on most maps of Afghanistan. But U.S. civilian and military officials believe what happens to the chockablock market here will be a key indicator of whether President Barack Obama can salvage a war the United States has been losing. About 4,000 troops -- most of them U.S. Marines -- descended upon Nawa and other towns along the lower Helmand River valley 10 days ago in a massive operation to root out the Taliban. Their aim is to combat the insurgency in a new way: Instead of targeting extremist strongholds, they will aim to protect communities from the Taliban. In Nawa, that means getting life back to normal. If that occurs, military commanders reason, it will be much more difficult for the insurgents to hold sway here. 'We'll be successful when we can walk up and down that street and most shops will be open, there will be a flow of commerce, there will be a recognizable and functioning government, there will be kids in school and doctors in the clinic,' said Capt. Frank 'Gus' Biggio, a Marine Reservist who is on leave from the Washington law firm Patton Boggs to lead a civil-affairs unit in Nawa. But employing U.S. forces to restore a sense of normalcy in a country ravaged by 30 years of war involves a series of assumptions and a set of challenges that are already proving more complicated than mounting hunt-and-kill missions against the Taliban. Will residents want the Marines to stick around? Will those who do be convinced that the Americans will stay until security improves? Will residents trust the local leaders -- including the police chief, whom one Marine officer calls 'the Tony Soprano of Nawa' -- to run the town better than the Taliban? An affirmative answer to those questions is not at all certain, and it will not just require the Marines to wage a different sort of war. The United States will have to spend billions more dollars to expand training for Afghanistan's army and police forces. Ineffective development programs will have to be overhauled. State Department diplomats and Agriculture Department specialists will need to deploy in larger numbers. And if the approach being employed in the Helmand River valley is extended to other areas under Taliban control, it could well result in the need for thousands more U.S. troops. Marines have been heartened by the initial indications in Nawa. A dozen stalls have reopened in the market. People have approached patrols to express support for the troop presence. And perhaps most significantly, the Taliban appears to have retreated -- for now. 'Thirty days from now, the people will say: `Okay. Great. You've cleared the Taliban out. Now what's in it for me?' ' said Brig. Gen. Lawrence D. Nicholson, the commander of Marine forces in southern Afghanistan. 'We have a very narrow window to bring about change.' From his plywood-paneled office at Camp Leatherneck, a sprawling and dusty base in the desert northwest of here, Nicholson understands that the same urgency applies to Washington. Nicholson's superiors -- including national security adviser James Jones, who recently visited Leatherneck -- are making clear that the clock is ticking: The Obama White House wants results within a year. Lessons From Anbar Helmand, Marines here are fond of noting, is the Afghan equivalent of Anbar, the once-lawless province west of Baghdad that was the focus of Marine operations in Iraq. Both are vast desert regions bisected by a river. The populations are tribal and religiously conservative. Criminal activity -- smuggling in Iraq and drug-trafficking in Afghanistan -- is rampant. Cross-border infiltration of fighters and munitions from Syria was a massive problem in Anbar; Pakistan plays that role with Helmand. Nicholson, a short, solid man with a weathered face and an intense gaze, gained his seminal military experience in Anbar. He was nearly killed there in 2004, when a rocket landed in his base near Fallujah. He returned in 2006 as a regimental commander and helped to implement a tribal outreach strategy that helped quell the violence. Although he is now in a different country, with different traditions and a different insurgency, he nonetheless sees lessons from Anbar that can be applied to Helmand. At the top of his list is the need for more indigenous security forces. Nicholson had wanted his troops to conduct every patrol and man every checkpoint with members of the Afghan National Army, largely because people here take less umbrage at being searched by fellow Afghans, and Afghan soldiers have a keener sense of who ought to be searched. But plans to partner with the Afghan army have been scaled back because the Marines have been allotted only about 400 Afghan soldiers instead of the several thousand Nicholson had sought. He has been promised more troops, but they will not start rolling in until next year. In the interim, he has asked his superiors for permission to arm young men and train them to serve as a local protection force. It is similar to the Sons of Iraq initiative the Marines created in Anbar that resulted in locals turning against foreign fighters in the group al-Qaida in Iraq. But senior commanders have shown no sign of approving the request. They feel Helmand has too many overlapping tribal rivalries. Arming groups of young men could exacerbate tensions and lead some factions to turn to the Taliban for protection. With that option closing, Nicholson has turned to wringing out as many soldiers from the Afghan army as possible. When he heard that a new battalion would be deployed to the south -- but not to his part of Helmand -- he flew to the NATO base near Kandahar five days before the operation began to ask a senior Afghan general for 30 of the soldiers. Nicholson promised to train them to be commandos. The general refused to commit and told Nicholson to talk to a lower-ranking general whose base adjoins Camp Leatherneck. So the next day, Nicholson dispatched three colonels to see the general for a lunch of goat stew and rice. 'General Nicholson wants to make sure we have an ANA (Afghan National Army) face wherever we go,' Col. Barry Neulen said. 'I wish the same thing, but I cannot promise them to you right now,' said Brig. Gen. Muhayadin Ghori, commander of the Afghan army's 3rd Brigade, 205th Corps. The men then began to negotiate. Ghori wanted to send two of his officers to the United States for training. 'They have to see the U.S.A., what it's all about,' he said. And the 30 troops? Ghori promised an answer. That was a week ago. The Marines still had not received any men. `Consolidating Our Gains' The Marine headquarters in Nawa is a half-finished government office next to the market that looked like the bombed-out shell of a brick building. The window openings are covered with ammunition tins and sand bags. Pit latrines have been dug in the back. Marines sleep in the open, on cots or directly on the floor. A mangy dog named Izzy scampers about. Within hours of the Marine landing, the town turned eerily quiet. Taliban attacks on the government office, which had been an almost nightly occurrence, ceased. So, too, did militant activity in other parts of town. Marines would later apprehend vehicles full of young men driving out of the district. In one car was a letter with instructions from a local Taliban leader to regroup in the town of Marjah, to the northwest. Lt. Col. William McCollough, commander of the Marine battalion here, professes little concern that many insurgents have simply moved away. 'While they're regrouping, we'll be consolidating our gains,' he said. 'By working with people here, we're seeing poison in the water. Every day they're away, it'll be harder for them to come back.' Because many Taliban fighters are disaffected Afghans who sign up in exchange for daily payments of $5 to $10, the Marines hope to lure some away with economic development projects. The Marines plan to offer day-labor work cleaning irrigation canals that snake along the farmland here, many of them built under a U.S. government program in the 1950s. The Marines are drawing on the advice of a British civilian stabilization adviser who lives with them at the government office, and the assistance of a large reconstruction team in Helmand's capital. Experts from the State Department and the U.S. Agency for International Development will arrive in Nawa this summer to assist with longer-term reconstruction and governance initiatives, including a $300 million program to provide agricultural aid to 125,000 farmers through vouchers to purchase seeds and farm equipment. That program will also seek to employ 166,000 young men in projects for six months. State and AID plan to have 20 Americans, and many more Afghans, working in Helmand by the fall. 'The numbers may not look big when you compare them to the Marines ... but it's not a (surge) that just goes in and leaves,' said Valerie Fowler, head of the local governance office at the U.S. Embassy in Kabul. 'It will be a sustained presence. We expect these positions to be filled year after year.' For now, the Marines are concentrating their efforts on helping the newly appointed district governor get to work and encouraging police chief Nafaz Khan to deploy his men, who typically loiter at the station, on key roads leading into town. The chief grudgingly agreed, but not before hectoring one of McCollough's officers for more uniforms and guns. 'I'm in the same clothes I've been wearing for the last 15 days,' Capt. Brian Huysman replied. 'Shall we kill the Taliban with our arms?' Khan retorted. 'We'll take weapons from the Taliban and give them to you,' Huysman said. 'You've only given us one gun,' Khan said. 'We have to kill more Taliban,' Huysman said. Thirty minutes later, a loud boom almost knocked Huysman off his feet. When he went outside to investigate, he saw Khan's men lowering a Soviet-era antiaircraft gun from the roof of the schoolhouse, where they had been living. The chief ordered that the massive gun, which spits out bullets the size of Magic Markers, be taken to one of the checkpoints. 'This is crazy, but what can we do?' Huysman said. 'He's the chief.' Marine commanders believe that working with police and local government officials will help their credibility among the residents of Nawa. But some in town do not share that view. 'We cannot trust the government or the Taliban,' Zary Sahib, the leader of the town's mosque, told McCollough. 'We can only trust you.' The Marines had stopped to talk to Zary the day after the operation began. The following day, he said, his brother was approached by insurgents who demanded 50,000 Pakistani rupees -- about $610 -- or the imam would be killed. McCollough reassured him. 'I think those are the guys we saw running away,' he said. The Marines are hoping memories of U.S. development efforts here a half-century ago will result in a degree of goodwill toward their mission. For years, Afghans referred to Lashkar Gah, the capital of Helmand, as Little America. And many older residents still remember the American teachers who worked in schools along the river valley. As a Marine patrol walked through the bazaar on a recent morning, its presence prompted a group of men sipping tea in front of a motorcycle repair shop to voice concern -- not that the Americans had arrived but that they might depart before the Taliban had been vanquished. 'If you leave, everything will be the same,' a middle-aged man who called himself Sayed Gul told McCollough. 'If you guys stay for a long time, everything will be fine.' 