As I buckled my seat belt, it struck me that flights to war-torn Darfur sure had improved since my last visit. In April of 2004 I'd flown to the overrun cities of Nyala, El Fasher, and Geneina, Sudan, in a rickety, propeller-driven Russian transport plane. The preflight checklist seemed to consist of the pilot and copilot barking at each other before throttling up. ("No fire!" "No smoke!" "Hit it!") Those were the early days of the world's largest humanitarian crisis.

Now the flight had a touch of civility to it. A Kenyan crew served water to the doctors, nurses, and other aid workers as they labored feverishly on their laptops. Flying with aid workers is always a lesson in efficiency. Every single person on the flight had either a computer open or papers stacked on the tray table. In front of me sat a breathtakingly beautiful Dutch volunteer physician, Petra, one of the 15,000 humanitarian aid workers now in Darfur. Two years ago, only a couple hundred of the toughest were here to help. Now a small army of determined professionals like Petra had answered the call, and their determination reminded me of my early humanitarian experiences in Africa.

When I was a young medical student in Sierra Leone in 1974, I lost patients every day to diseases that could have been treated with a course of antibiotics or antimalarials back in the States. Meanwhile, near my quarters lived a 75-year-old Peace Corps volunteer who went out every few days to put in a new drinking well in some needy village. With my training, I could only comfort the sick as they died. By seeing the larger threat, this volunteer was saving scores of lives with each well he installed.

Since then I've tried to see things as that 75-year-old did. Stepping in at the right point can make all the difference, and I wanted to try to do that here in Sudan. After Rwanda, President Clinton apologized on behalf of the international community for not acting quickly enough to protect the refugee camps. Sudan is looking like another apology in the making. I was filming a television show with cameraman Kevin Broad, and I'd set my sights on telling the story of Darfur and its people through the eyes of International Medical Corps (IMC), a group of physicians who race to provide medical care and training during international disasters. IMC began in 1984 when an American ER doc sold his house to start an emergency medical program in Afghanistan, and today it enjoys the favor of the U.S. State Department because it's less politically outspoken and more technically accomplished than comparable groups. The IMC doctors are nothing if not devoted. In 1992, in Somalia, I witnessed an IMC physician roll up her sleeve and take a pint of blood out of her own arm to save a little girl's life.

The town of Geneina, on Sudan's western border with Chad, is within a few hundred miles of the Sahara, and as we descended toward the dirt runway the small details came into focus: brown buildings and scattered single trees amid an endless landscape of rock and dust. We emerged into a breathtaking blast of bright sky and dry heat. Beyond the waiting jeeps encircling the plane, the place was still firmly in the 15th century. I watched two men ride donkeys past a smattering of low whitewashed buildings at the runway's edge as passengers marched off the plane to extricate their bags from the pile on the ground where they'd been thrown.

At its core, the Darfur conflict is based on an ethnic division. In 2003 two local rebel groups, the Sudanese Liberation Army (SLA) and the Justice and Equality Movement (JEM), both composed of African Sudanese, began a bloody rebellion against the Arab-dominated Sudanese government. The government allowed militia groups to sweep through Darfurian villages in search of SLA and JEM rebels, and indiscriminate murder became common on both sides – 50,000 to 80,000 dead by the summer of 2004, an estimated 200,000 dead today. As the UN prepares to send in a peacekeeping force, against the protests of the Sudanese government, Darfur is pocked by random violence: government troops and government-backed militias fighting multiple rebel groups, Chadian rebels and Sudanese rebels and bandits on cross-border raids against Chadian government troops, rebels and bandits sacking aid convoys for supplies, and unaffiliated thieves stealing NGO vehicles and equipment. Geneina is a melting pot of aid organizations, military personnel, and profiteers, and it takes a practiced eye to identify the various jeeps full of khaki-clad armed men flashing through town.

A peace treaty between one rebel group and the government went into effect this past May, but several other groups refused to sign, so the region is teetering on the brink of all-out warfare again. The African Union force, some 7,000 soldiers from various countries, is stretched too thin to handle it and, shortly after my trip, announced its intention to withdraw. Geneina sits squarely within the danger zone, and when we got there the UN had imposed a stage-four alert status for foreigners on the ground. Stage five is immediate evacuation. When I arrived, my name, along with the names of every aid worker and foreign official in Geneina, was attached to a particular seat on a particular plane, ready at all times to get us the hell out of there.

The scene at the airport was like Saturday night at a drive-in: a fleet of Land Cruisers idled near the plane with their drivers and greeters, each with a large logo on the door: imc, msf, save the children, wfp, un. As passengers disembarked, old hands hugged one another and newcomers looked around anxiously for their rides. Meanwhile, we got into brief trouble with a group of government officials who'd spied Kevin's photo equipment. For months, reporters had been barred from Darfur; most were stuck in the capital, waiting for permission to come here. My application had been expedited because I'm a physician, but letting us loose with a camera seemed to the officials a sure way of losing their jobs; we would have to return to Khartoum. Then I opened my laptop and revealed a shot of myself with the casually dressed and unusually cheerful-looking president of Sudan, Omar Hassan al-Bashir, at his house in 2001. The official in charge broke into a desperate smile, bid us a sudden welcome, and ushered us politely out the door.

Geneina is a collection of compounds, each protected by head-high stone walls, owned by well-to-do farmers and businessmen and rented to various aid organizations. They reminded me, inside and out, of the Alamo. We walked through the gates of the IMC compound, our base for this visit, as the midday sun began to slide toward afternoon. A Kenyan nurse gave us a tour of the spartan camp, clean and well-swept but coated with windblown dust at the end of each day. A single, low building stood at the center, with sandbags piled high to afford ready protection from any attack. Linens hung on clotheslines, and piles of supplies were stacked all around.

In Geneina thieves are the primary threat: rebels with a side business trafficking in stolen goods, Arab militias, or organized bands of unaffiliated robbers. IMC's crates of medications had been moved inside the lone building to protect them. NGOs were losing vehicles and supplies to armed bands at an alarming rate. Even high-level diplomats were arriving only to find their cars had been stolen and more than a dozen aid workers, mostly Sudanese, had been killed since May. Transporting anything overland, an aid worker told me, was a guaranteed way of losing it. As a result NGOs were moving food and supplies by air.

Settling down in my small bedroom, I worked through a typical Darfur evening routine: kill bugs, set up mosquito net, stare at ceiling, kill bugs, wait for temperature to drop to 105. The faint sounds of fighting – the familiar pop-pop of AK-47 fire, the occasional soft boom of an RPG round – lulled me to sleep, despite the thick evening air. Two years earlier I'd slept in an iron shipping container. At least this time I had windows.The next morning we squeezed into Land Cruisers with the aid workers and a few bodyguards cradling machine guns in their laps and set off down the slope into a shallow valley at the far side of town. A green trestle bridge took us across a dry riverbed and then, atop a plateau at the other side, we came to the Riyadh, a camp for tens of thousands of displaced Darfurians. Tents and shacks stretched away out of sight, the closest put in place by IMC, the rest constructed haphazardly out of sticks and blue tarps by the residents themselves. In all nearly 2 million internally displaced people (IDP) are adrift in Darfur, typically driven from their homes by scorched-earth military campaigns intended to burn rebels out of their hiding places in rural villages. Many were innocents who had simply gotten caught in the crossfire. The people I was looking at were lucky to be alive.

We walked slowly into the camp, and curious children rushed to surround us, gently touching our clothes and laughing. It was quickly apparent that aside from a few small groups sitting together in the shade of single trees, the conflict had stolen or killed all the men, leaving this encampment of widows and orphans to fend for themselves. Women foraged for firewood at the edge of the camp and tended cooking pots within their tents, while the children spent their days pretty happily: drawing pictures with crayons in one tent, learning to read Arabic in another, or playing volleyball outside. But the upbeat feeling evaporated when I sat down with them.

"Antum mabsoot or hazeen?" I asked. Are you happy or sad?

The shy smiles disappeared. "Hazeen," they said in chorus. Sad.

They began to show me drawings of the horrors they'd witnessed. A mother and father lay on the ground next to a small house, blood coming out of their bellies. A machine gun sprayed bullets at a group of stick figures. Helicopter gunships swooped above a crayon village.

A few children took us to the camp's edge and pointed down at the plain below. Death – "mout" – awaits us there, one said quietly. Anyone who walks out of the camp is at the mercy of marauding rebels. Viewed one way, these children were safe. Viewed another way, they were trapped.

In the medical tent I watched Dr. Ali Dowelbait, IMC's physician on the scene, as he examined each in a long line of patients. A young, meticulous Sudanese doctor, he looked into eyes, felt skin, and listened to hearts and breathing as if each patient were the day's only appointment. Many found it unsettling to have a stranger touch them. But his friendly manner and murmured assurances broke through their fear, and by the end of the examination, emerging from the tent with medicine in hand, or, better yet, a clean bill of health, each smiled with relief.

After a few hours of touring the camp and speaking to residents, I asked how malnutrition had been affecting the camps, and we were taken to the therapeutic feeding ward at Geneina's hospital. It's set apart from the other buildings, and as we entered the ward one child, Yahia Abdullah, stuck out immediately.

For better or for worse, I have an eye for starvation. I've been present at terrible famines, and I could tell instantly that Yahia had true marasmus, a severe wasting of the muscles – the worst kind of malnutrition. You've seen it in photos of Ethiopia, circa 1984. His stomach was distended, his arms thin as my thumb, his smile a grimace. His mother Miriam had to help him sit up.

Starvation affects a child's personality in several ways, and most doctors will tell you that it's more tolerable to look at the emotional transformation as a physiological symptom. Like any starving child, Yahia was terrified. As his body began to shut down, he had grown edgy and miserable, as if he were being tortured. I'd rather see a child react strongly to that feeling – meaning there's fight left in him – than be listless, as Yahia was. He was beyond fighting. His eyes were dull as he watched me go, and I left the tent with his hopeless face burned into my mind.

In the past two years, I was relieved to learn, the UN World Food Program (WFP) estimated that the rate of acute malnutrition in Darfur had dropped from 3.9 percent to 1.4 percent, a miracle for a region at war. But now that I'd seen Yahia and the rest of the feeding ward, it was obvious that if the pace of development slackened or stopped – because of donor fatigue, or, worse, all-out war – the already desperate situation would be a disaster. As it was, the conflict was keeping the WFP from reaching nearly half a million people. Even if peace is kept and aid workers stay on, the region's infrastructure is gutted; it will cost millions to reestablish homes, schools, water systems, electricity, and community police forces. The camp's children looked healthy, but throughout the region supply routes were being pinched off as rebel factions, too many to negotiate with as a unified entity, took control of new territory and dug in for the long-awaited conflict with the government. Violence might cause the UN to pull out of the area, and everything would unravel. As I walked back to the IMC compound I thought about Yahia. If international aid were cut off, it would be the end of him, and of Darfur's prospects as a whole.

The next morning we followed Dr. Jill John-Kall, IMC's medical director for Darfur, back across the bridge to a camp called Abu Zar, a few miles beyond the Riyadh. A hard-charging New Yorker, perhaps five feet tall, Jill's passion shone through immediately. Although latrines were backed up and there was a two-day wait for water, she gushed about her job as the children swarmed around her. "I love this work," she said, wiping her brow in the 114-degree heat. "I can make so much more of an impact here than I can at home."

She quickly examined the children around her, handing them off to aid workers with the efficiency of a doctor obviously accustomed to quick and decisive triage. "Conjunctivitis," she said, pointing at one child's eye. She listened to another's chest. "Pneumonia." She instantly diagnosed more than a dozen cases as the children (and I) looked at her with the same mix of affection and awe. "They like me because I'm their size," she said with a humble smile. The rest of the afternoon was like a game of hide-and-seek as she darted with her stethoscope among the kids, several of whom stood taller than she did.

Just as we prepared to leave I noticed a young boy hiding in the crowd. I couldn't miss him. He was horribly disfigured by a cleft top lip that tore all the way to his nostrils, exposing his jumbled upper teeth. While these camps are adept at treating acute problems like dysentery or dehydration, kids with chronic conditions like heart trouble or, in this case, a cleft lip, have no chance in Sudan. "What can we do?" I asked Jill. Her pragmatism rose to the surface. "Nothing," she shrugged sadly. For the cost of his surgery, countless children could be rehydrated and saved from diarrhea. In Iraq I had started an organization called Operation Lifeline Iraq to help treat children with cancer by transporting them to hospitals in Jordan. There had to be a way to do something similar here. I couldn't imagine this poor child living his life as badly deformed as he was, unable to even close his mouth. He looked at me and I looked away, embarrassed.

Sudan is on the state department's list of terrorist nations (Osama Bin Laden got his start here between 1991 and 1996), and Darfur's future will be determined by whether security can be established, not just in a military sense but also on a community level by local police. Traditionally Sudan has been policed from garrison-style fortifications from which the police make only occasional forays. The country is now trying to make a transition to Western-style police work with community-level presence. I'd asked before arriving to be introduced to the regional commander, and that afternoon at the IMC compound a messenger arrived, inviting me to dinner.

As an NBC correspondent in the '90s I'd heard lurid stories from rebel leaders here about the devils who ran the northern Islamic state – how government soldiers looked like vampires, with yellow eyes. So it was with some trepidation that, a little before curfew, I crossed the colonial courtyard of the police guesthouse in Geneina and stepped inside. A group of tall, fierce soldiers turned my way, tea in hand, guns propped in a corner. In the middle of them stood an enormous man with a mustache, Major General Abdulbagi Mustafa Ahmed, the most senior police officer in the region.

Of all armed entities in Darfur, the police have the greatest interest in peace and the toughest challenge maintaining it. They're charged with holding together the fabric of society by establishing patrols, quelling everyday crime, and earning local trust, even as the Sudanese government that pays their salaries prepares for war, and as the communities they patrol give rise to rebels bent on violence. With their weather-beaten skin and hard features, they had the bearing of ancient warriors. Newsprint covered the floor between us, and as I removed my shoes and stepped forward onto it to greet them they made alarmed gestures. I stopped. One of them knelt down to reveal our dinner staying warm beneath the paper, and everyone burst into laughter. "Salaam al-laykem," one of them said. ("Peace unto you.") "Al-laykem a salaam," I answered with relief, offering a handshake. "Ismik manha?" ("And also to you. What's your name?")

Despite years of warfare, Sudan is one of the friendliest countries I've ever visited. "Kellam Arabee!" they marveled. ("He speaks Arabic!") As a reporter I had tried for eight years to embed with Sudanese security forces, with no luck; policemen, soldiers, and security personnel had been strictly off-limits to the press. Sitting down to dinner with the police I felt triumphant. I listened and nodded and interjected politely as they discussed their plans to make the region safe by establishing no-go zones around rebel fortifications and by developing a reliable framework of security everywhere else. We spent four long hours discussing these issues in Sudanese Arabic, which stretched my vocabulary to the limit. At the end of the evening they agreed that I could accompany a patrol to the border of Chad, where we'd heard gunfire the night before.

The next morning, we met our appointed guide, Dr. Salim Salim, an English-speaking Sudanese doctor who would drive us, with a police patrol, to the border. Dr. Salim trained at the London School of Hygiene and Tropical Medicine and was here to set up a police hospital. Darfur is the size of France and impossible to patrol completely, with armed factions ready to shoot anyone who threatens their control of livestock or crops. But the police were trying to establish regular patrols across the region, because without secure trade corridors towns like Geneina would be cut off. Halfway to the border we saw police fanned out, standing guard over a crossroads, one of thousands used over the centuries by nomads arriving from the Sahara and now a favorite spot for ambushing supply columns. Trucks returning from Chad rolled into sight, carrying supplies for Geneina. Passengers were sprawled across the cargo, and on the hood of each truck sat one or two policemen carrying AK-47s to defend the loads. This stretch of Darfur is one of the least secure. We watched as the overloaded truck rolled by, its police escorts tensed for gunfire.

We proceeded into Asunga, a small town directly on the border with Chad. It's an outpost of trade caught between Chad's military on the far side and rebels in Darfur. A lone flag waved above a one-room house for the Sudanese border guards, the most permanent-looking structure among the smattering of thatched huts along the road. Because of the intense military and police presence, there was commerce in this unlikely place, with knockoff T-shirts, tea, grain, and fresh meat for sale. Salim pointed out that with regular policing, the whole country could be this way.

"There are massive amounts of oil on either side of the border, plus substantial deposits of uranium," he said, waving away flies as he steered. "This could be one of the most prosperous parts in all of Africa if we could just establish security." But they aren't even close yet. With the sun setting, we sped back to Geneina to avoid getting caught out after dark.Leaving a disaster site by plane is the most stressful kind of travel. Miss our appointed spots on this flight and we'd be stranded in Darfur: the ultimate nonrefundable ticket. And so, on our last day there, even after we'd packed our bags, we were feeling understandably rushed. We walked briskly to the hospital to check on Yahia. Entering the feeding center, we couldn't see him in his bed; the concrete room was practically empty. My heart fell. Then Kevin, my cameraman, whispered, "Over here!" There was Yahia, dozing. I looked at his chart and roused him gently to examine him. The good news was that his malnutrition had improved, from phase one (life-threatening) to phase two. He was gaining weight. Then came the bad news. As I listened, his chest rattled with the sound of lobar pneumonia. Worse still, the hospital was out of antibiotics. One of his doctors showed me a slide of his sputum. It revealed the culprit: big, dangerous, hospital-acquired bacteria, a Gram-negative infection that would without question kill him off if untreated.

And here, as I'd hoped when I arrived, I discovered myself at the intersection of supply and demand, putting disconnected pieces together. Dr. Salim, assigned to the police, would, I knew, have access to the proper antibiotics. We should have been at the airport by now but instead we hopped in a jeep and drove like mad to the police hospital to explain the situation. Without a word the doctor led us on a sprint to his store of gentamicin, precisely the antibiotic Yahia needed, then returned with us to the hospital. I reassured Yahia's mother Miriam in Arabic, explaining that this medicine would save her son's life, and Yahia began wailing. He was fighting back. I glanced at my watch while I stood with Miriam for a moment as she held Yahia in her arms to comfort him. She nodded thanks, and I nodded back before walking away.

Jill joined us as we got back in the jeep, and I turned to Dr. Salim. "We met a poor boy with a cleft lip," I told him. He tut-tutted with sad understanding. "There must be something we can do for him," I went on.

"The police hospital in Khartoum could perform the surgery," Salim volunteered.

"IMC could fly him out," Jill added.

"And if all else fails, I'll pay his way," I said.

We had only 15 minutes until the plane left. Sliding into a four-wheel drift around the last corner, our Land Cruiser skidded to a halt outside the Abu Zar camp. With the clock ticking in my mind we hurried into the courtyard. My shoulders slumped at the sight of a yard full of kids. "This is going to be impossible," I said, surveying them, when suddenly Jill, in spite of being the shortest among us, spied him.

I walked up and gently asked that he get his mother. He returned in a few moments with a young woman holding a baby in her arms. "Would it be okay to send you and your child to Khartoum in a few weeks' time?" I asked her, grasping for the proper Arabic. "We will pay for surgery to fix his mouth." Women in Sudan age quickly; this woman of 20 or 21 had the weary face of someone 10 years older. She gave me a hard look at first, then burst into a smile. Suddenly she was a beautiful young woman. She looked at her son, then at me. "Na'am!" she nodded.

In spite of the urgency, we had to follow protocol. I led the boy to the village elders, who were gathered under an enormous shade tree. Even here, robbed of their livelihood and their independence, they still commanded respect and allegiance. After the long traditional greeting I launched into my pitch, trying not to sound rushed. "May I have permission to take this boy to Khartoum?" I asked in Arabic, explaining how we planned to help him. They talked among themselves, and then smiled. "Na'am," they said, with a gesture of agreement. I touched the boy's shoulder good-bye – Salim would make the arrangements from here – and trotted back to the jeep. We hit the runway as the ancient 727 started its engines; as we boarded, the flight attendants were preparing for takeoff by reinstalling the emergency exits and doors, which had been left off in an attempt to cool the sweltering plane.

I sat down, breathing and sweating hard, just as the engines surged. As we accelerated, my mind kept racing with the details of our morning. Would the antibiotic keep Yahia alive long enough to attain a healthy weight? And what about the other boy: How would someone who'd never been in a plane feel about being whisked to Khartoum for surgery? And then, as the plane rose and banked, the landscape stretched out in front of me, revealing Chad, and the Sahara, and the constellation of needs and difficulties I'd encountered on the ground expanded into the larger problems. I pictured Dr. Dowelbait and Dr. Salim, and then imagined the thousands more like them – the will of a whole nation, determined to enact a better future. What would happen if UN forces couldn't take control of the territory? How would the camps survive if supplies were cut off by all-out warfare? And then, as Kevin ran through his photographs next to me, I thought of the aid workers on the flight here. They hadn't been staring out the window, ruminating on the larger picture. They'd been focused on what was in front of them, on doing their part.

The Conflict

Who's Involved

In 2003 Darfurian rebels attacked a government base in El Fasher. The Sudan government responded by asking Arab militias to purge villages of rebel groups, such as the Sudanese Liberation Army (SLA) and the Justice and Equality Movement (JEM). Hundreds of thousands died as a result.

Why They Fight

As grazing lands are swallowed by desert, pressure on the land has inflamed tensions in a region already divided between Arab herders and African farmers. The rebels want a share of potential oil wealth.