For nearly 14 years, rebels have clawed their way across the vast, empty plains of southern Sudan.
Their mood is buoyant. They are winning - for now, at least - and at a military camp between two silty rivers, troops of the Sudan People's Liberation Army wake up singing."Open the road. We are coming," they chant.
The rebels have gained a strip of land along Sudan's eastern border in an offensive that began last March and are pressing toward a dam straddling the Blue Nile that provides most of the electricity in Khartoum, the capital, 290 miles northwest.
The rebels say they are fighting for survival, equality, freedom of religion and respect.
For the Sudanese government, the conflict is a "jihad," a holy war, as it seeks to force Islam on the Christian and animist south of the country. Its weapons are conversions, either forced or bought - the going price is the cost of a shirt - famine, political repression, torture of dissidents and outright slaughter.
Since becoming the first sub-Saharan African country to gain independence 38 years ago, Sudan has been at war for nearly 28 years. Cmdr. Malik Agar, a 47-year-old rebel, says his side is making gains now because it finally overcame a crippling split in its ranks.
Still, he said, the war "will go on for quite a time."
Malik said fighting is the only option: Negotiations won't work because the government insists on forcing Christians to obey Islamic laws.
He said he was "peacefully forced" to convert to Islam; if he hadn't, he wouldn't have been allowed to go to school.
While teaching Arabic in Khartoum, he realized he was still an unequal citizen: At the mosque, he said, he had to pray behind Sudanese of Arab descent.
"You are a second-class Muslim and a fourth-class Arab. So why not be a first-class Malik?" he said.
Recent rebel advances in southeastern Sudan included a claim, published today, that nearly 1,000 Sudanese government soldiers had surrendered to the rebels after rejecting government orders to fight.
"We will not stop the war before the regime falls . . . As for the army, most of them refuse to fight their people," rebel leader John Garang told the Egyptian weekly al-Mussawar.
The U.S.-educated Garang founded the Sudan People's Liberation Army in 1983, attracting followers like Cmdr. Peter Parnyang Daniel, who quit his teaching job to join.
Like many others, Peter was angered by a government plan to build a 225-mile canal that would have deprived the south of water.
The project was one of the rebel's first targets, but since then, the battle has expanded. More than a decade in the bush has cost Peter a chance at higher education, a wife who wearied of his years-long absences, and many friends killed in battle or lost after breaking off into rival factions.
"It is too late to give up," said Peter, 43. "I have to finish this."
His men's uniforms are a mix of pants and shirts often scavenged from dead government fighters. Many are barefoot. Some have thongs. Few wear boots. Their weapons are whatever can be bought on the black market.
With guns slung over their shoulders instead of traditional spears, they lope gracefully over long distances as they patrol their newly captured land.