independent

The uneasy peace that has kept the two disparate halves of Africa's biggest nation together is under threat

As Sudan approaches its fifth anniversary of peace, the fragile accord which has held the north and the south together is unravelling and Africa's biggest country is sliding back dangerously towards what was the continent's longest war. Momentous elections are due in a matter of months, a referendum on separation looms and Sudan's complex ceasefire is in open crisis.

All over the south there are soldiers in new uniforms; the army was paid for the first time in six months last week. Around 2,000 people have died in violence there this year and the government of southern Sudan says small arms are pouring across the border. In the north, which is led by Omar al-Bashir, the president wanted for war crimes, opposition leaders have been jailed after protests over democratic reforms and crisis talks in Khartoum have failed to halt public demonstrations.

"Now we're seeing the crunch," says Sudan analyst John Ashworth. The "endgame" of the historic Comprehensive Peace Agreement (CPA) has arrived, he explains, and the fact that "the north gave away more than it could afford" to get the ceasefire means new conflict is almost inevitable.

Tunguer Kueigong is among those who think that 2009 will be the last year of peace. In Bentiu, the dusty capital of Unity State, the paramount chief of the Nuer, southern Sudan's second largest tribe, holds court in his "office" under the shade of a mahogany tree. "You know the north will not just let the south separate like this," he says, matter-of-factly. "If it happens, the people must fight."

The traditional leader understands better than most that the biggest obstacle to peace is oil. Unity State produces half of Sudan's oil. His time as chief has coincided with the discovery of the first sign of Sudan's huge oil wealth, here in the state 33 years ago.

Tunguer's playful garb, sunglasses and a Manchester United cap pulled tight over his head, belie his status. Southerners from ministers to herders come to his "office". Gesturing occasionally to his unopened briefcase perched on a plastic stool, he explains the benefits that oil has brought to Unity State. "When we didn't know we had oil we built schools and clinics," he says. "Because of the oil there is nothing."

Since the discovery of crude, the preferred method of extraction has been to clear the local population by force and meet any opposition with overwhelming military power. For much of the last three decades this has meant war. The fighting in Unity State, Tunguer recounts, has seen people being bombed in their villages, burnt alive in their huts and children rounded up and marched north to become slaves. "When we tried to fight them we had only small guns; they had bombs," he says.

The reality of Unity State sits uncomfortably with its name. A super-hot expanse on the western fringe of the great Sudd Swamp, it sits on the northern border of what may become South Sudan under the terms of the deal that ended the civil war. For now it looks politically to the south but its economic wealth is pumped north to the Arab-led government in Khartoum.

Its oil fields are guarded by army units dominated by northern security forces, with two of them outright occupied by the northern-controlled Sudan Army. The state infrastructure has been built in spite of its people for the purpose of extraction, not development. Its countless miles of straight roads were built to transport oil, not to connect communities.

Unity is home to the cattle-herding Nuer and Dinka, southern Sudan's two largest tribes. With its rich resources, impoverished people, tribal tensions, history of violence and predatory extractive industries, the state is a microcosm of this troubled country.

While the Darfur crisis in the west of Sudan dominated world headlines, the tortuous negotiations that led to the CPA, which marks its fifth anniversary next month, commanded greater interest in the country itself. The deal ended a conflict that claimed 2 million lives and left Sudan with a generation born into war. The fighting, which pitched the primarily Christian and animist south in a guerrilla campaign against the Arab-led north, registered strongly in the US where the Christian lobby led by Billy Graham pushed Washington to take sides.

Diplomats are concerned that a new round of fighting could see a proxy conflict between Khartoum's main sponsor, China, and the Western allies of the south, including the US. Under the terms of the ceasefire between the military government of President Bashir and the Sudan People's Liberation Movement (SPLM), the south has governed itself for an interim period before nationwide elections are held in 2010, followed by a southern referendum on self-determination in 2011.

With the country's first national poll in a quarter of a century coming, the south is wracked by violence. Medical group Doctors Without Borders said this week that 2,000 people had been killed and another 250,000 displaced during 2009. Legislation supposed to define how April's elections and then the 2011 referendum would work remains unsigned in Khartoum ahead of next week's deadline. A partial deal on Sunday was hailed by both sides as a "breakthrough" but many in the south remain sceptical about whether elections will be held at all.

The question of who would control Sudan's oil revenues after a potential split in to two countries is completely absent from the CPA. A newly created South Sudan would contain as much as 87 per cent of Sudanese oil, much of it in Unity State, Upper Nile, Jonglei and the contested Abyei area, which is also due to vote on joining the south. "These are the states the north cannot afford to lose," says Mr Ashworth, an analyst with the Dutch-based Pax Christi peace institute.

For the vast majority of southerners long-cherished independence is on the horizon and with it, freedom from decades of misrule and the imposition of unwanted Sharia law. For the north, there is the prospect of losing half the country and two-thirds of its income.

Khartoum points to the mounting death toll as evidence that the south is ungovernable. President Bashir's opponents accuse the government of funnelling arms and money into the south to destabilise it and delay a vote on separation. "The north relies on the principle of divide and rule," says Taban Deng Gai, governor of Unity State. "They will not allow the south to be a feasible state." He accuses Khartoum of recruiting militias again, a tactic which was used to devastating effect during the civil war.

In the last four years of the 22-year war, Unity State saw a reign of terror led by the militia of Paulino Matip, a Nuer warlord who defected to the northern camp. President Bashir was indicted by the International Criminal Court for crimes against humanity after using similar militia tactics in Darfur.

There is disagreement over the origins of violence in the south but the prolonged civil war undoubtedly incubated rivalries between major ethnic groups. Much of this year's fighting, however, has broken the mould of previous cattle raids and skirmishes with large-scale massacres occurring.

Even on the political level there are deep divisions. The SPLM is dominated by the Dinka and led by Salva Kiir Maryadit, the president of southern Sudan. Power struggles between the president and his Nuer vice-president, Riek Machar, have almost paralysed the movement, which would rather skip the April elections and move straight to a vote on secession from the north.

In the meantime, much of the meagre oil revenues that have gone south have been absorbed by corruption – a fact acknowledged by Washington which recently cut aid to the administration in the south's capital, Juba.

While President Bashir denies interfering in the south, analysts suspect that Khartoum will seek to contrast a peaceful vote in the north in April with predicted unrest in the south. This could then be used with the international community to argue for a delay in holding a referendum. However, any stalling over a vote on secession could also see the south declare independence unilaterally.

If the referendum bill is not agreed before parliament is dissolved on 23 December "then war is imminent", said a senior foreign intelligence source. He added that any attempts to delay the historic referendum, pencilled in for 9 January 2011, would provoke a violent response from the south: "On the 9th expect a referendum or a bloodbath."