In Sudan, the Pull of Peace and Oil

Violence has since subsided, and Salva Kiir Mayardit, Garang's longtime deputy in the rebel Sudan People's Liberation Army, has taken his place as the nation's vice president.

Even so, some harried returnees, including Thian, have made contingency plans to go back to the United States. But for now, he said, "I will stay and see how it plays out."

Thian and his friends from the diaspora often stroll the rutted, red-dirt paths around Rumbek. They have learned a local joke about riding home on "Bus 11." To explain, Thian slapped each of his long legs.

"One plus one equals 11," he said with a rueful laugh. "My legs are the only transport in South Sudan."

There are, in fact, no buses in Rumbek, the south's interim capital. Nor is there a bonded banking system, a newspaper, a civil administration or even a motorbike service to carry villagers to and from town.

Still, Rumbek is flourishing compared with places less than 100 miles away. In rural Aweil County, feeding centers are filled with malnourished children at rates even higher than in Niger, according to James Lorenz, a spokesman for Doctors Without Borders here.

The food crisis has been caused by a combination of factors, Lorenz said, including wartime land mines that impede farming, a surge of about 78,000 returnees from Khartoum, and several thousand refugees from Sudan's separate war in the western region of Darfur.

The region's land is so fertile that, once developed, it could feed the entire Middle East, a recent U.N. study found. But the war, which took 2 million lives and displaced 4 million people, has kept southern Sudan in a primitive state, with antiquated farm tools, no running water and women more likely to die in childbirth than finish primary school.

To build a modern society and retain public support, leaders must make the transition from guerrilla movement to government, unite fractious militia groups and quickly develop services and infrastructure.

Most people here see the discovery of oil as the best chance for prosperity. But they also fear it could bring nepotism, corruption and chaotic fighting, as has happened in neighboring Congo, where thuggish militias battle for control over gold and diamond resources.

"The enormity of the task is numbing," said Steven Weindu, the former rebel group's representative in Washington, who was visiting Rumbek. "We have a lot of sharp edges to smooth out. Anyone who returns has to have faith."

Sipping mango juice and smoking cigarettes, a group of Thian's friends crowded into an office set up to interview professionals for jobs.