By Alex Dziadosz
KHARTOUM (Reuters) - North Sudan has sent in the army along the vaguely-defined border area between north and south to stamp its authority there and eke out concessions before the south splits away with most of the nation's oil.
Khartoum sent tanks into the disputed Abyei region on May 21 and two weeks later sent troops to crush southern-aligned fighters in Southern Kordofan, which has the most productive oilfields that will be left in the north after July 9.
The north Sudanese government seems to be betting the south, which voted to split in January, will be reluctant to challenge the north's mightier army and risk a war that could threaten its goal of recognition from Khartoum as a new African state.
But Khartoum's strategy has already angered Western powers, whose goodwill may prove vital in securing up to $38 billion in debt relief. It also fuels tensions in areas that produce oil, the lifeblood of both the northern and southern economies.
"(Northerners) are underdogs from the economic side. They are going to be more affected by the secession than the south. They want to offset that by being the 'upper dogs' on the security side," said Fouad Hikmat from the International Crisis Group think tank.
Asserting military strength along the border could give the north leverage as the two sides hammer out unresolved questions like how to manage the country's oil proceeds and divide debt.
"They are trying to corner the SPLM (the south's ruling Sudan People's Liberation Movement). They are putting the SPLM in a very difficult situation in Abyei, Southern Kordofan and Blue Nile," said Hikmat.
Sudan's vast area and webs of ethnic and tribal loyalties have defied easy division, leaving flashpoints in border states like Abyei, Southern Kordofan and Blue Nile.
DIVIDING A NATION
Khartoum's specific goals differ in each region.
In Abyei, with its valuable pasture land and some modest oil production, the north wants concessions, analysts say. The area is claimed by both sides. But a plebiscite on its fate has not happened because of disputes over who should be allowed to vote.
In Southern Kordofan, the north wants to crush a well-armed and seasoned group of fighters, many from the ethnic Nuba group who sided with the SPLM's military wing in two decades of civil war that ended with the 2005 peace treaty. The north fears a resurgence by the group could threaten a vital oil area.
The 2005 treaty led to the referendum on secession, when Southerners overwhelmingly backed a split. It set the stage for Africa's largest nation to be divided. But, until now, that had proceeded with far less violence than many had predicted.
Even when divided, the two nations will depend on each other. About 75 percent of Sudan's total 500,000 bpd of crude output lies in the south. But exports depend on a pipeline that passes through the north.
Southern President Salva Kiir, speaking in May when the Abyei conflict flared, said the south would not strike back.
"We thought that as neighbors we would be the best friends. We need them and they need us," he told a news conference.
But, as the deadline to separation approaches, analysts said Khartoum is determined to show it is the more powerful partner.
"Khartoum's view of the July 9 date for Southern independence is rather different from Juba's," Eric Reeves, a researcher at Smith College and activist on Sudan issues, said.
"It wishes to settle various issues by military force, to change the facts on the ground as of July 9," he said.
In Southern Kordofan, the north said it would not tolerate an armed group within its boundaries and demanded the Nuba fighters disarm or leave. Juba says it cannot ask the fighters to go south because they are northerners and not part of its army.
The result could be a long guerilla war pitting the north against fighters who are familiar with the area's hilly terrain. That would disrupt trade and transport with the south and also open up Sudan's President Omar Hassan al-Bashir to more international criticism.
Bashir is already wanted by the International Criminal Court on charges of masterminding genocide and war crimes in Darfur, another area that will stay in the north and where rebels have fought with Khartoum accusing it of neglect.
"I don't think it's really possible for the Sudanese armed forces to achieve complete victory in Southern Kordofan," said Aly Verjee, researcher at the Rift Valley Institute think tank.
"They can drive the opposition into the mountains and weaken their classic military capabilities but they won't fully defeat them," he said.
Humanitarian groups fear a mounting death toll in Southern Kordofan. Over 60,000 people have fled, the United Nations says. Human rights groups have accused Khartoum of waging a campaign of "ethnic cleansing" against the Nuba.
Khartoum rejects this, saying it is fighting an armed rebellion and the army is there to protect civilians.
More than 100,000 have also fled violence in Abyei. The two sides signed a deal on June 20 to pull troops out and bring in Ethiopian peacekeepers after talks in Addis Ababa. But analysts say conflict could flare up again without a long-term solution.
Talks on Southern Kordofan have made less progress, officials say, with the north telling the south that it is an internal issue and they should not interfere. Even if a deal is reached it might not carry weight with Nuba groups who felt left out of the 2005 deal that left Southern Kordofan with the north.
"We might see, politically speaking, a de facto division of the state (Southern Kordofan)," analysts Verjee said.
"Not one with a nice, neat boundary, but one where pockets of the SPLM and associated elements are able to survive and exert control," he said, comparing it to the pockets of resistance that have held out against Khartoum in Darfur.