Leading article: Sudan's biggest test is yet to come

An oil-rich state riven by confessional and ethnic divisions, poisoned by the legacy of two civil wars, is about to do something remarkable.

Tomorrow Sudan will allow its southern half to break away using the ballot box. What makes the vote by citizens of Southern Sudan even more remarkable is that most of the country's oil will end up to the south of the new borders. This alone has prompted many to wonder if splitting Africa's biggest country would trigger a new civil war. So far it hasn't.

But whatever Southern Sudan's politicians tell their people, the new country will not enjoy the lion's share of oil revenues. Independence for the south has been bought at great expense and much of the new state's potential income will transfer to Khartoum in the form of contractual fees for the transport of oil. These payments are the price the north is exacting for letting go.

On the ground, little will change as northern-controlled security forces will police the oil fields on the new borders and the only pipelines will still head north. This is the "shared destiny" that pragmatists argued was essential for an amicable divorce. It will do little to satisfy the influential Darfur lobby that seethes at the deals being struck with the government of the alleged war criminal Omar al-Bashir. If the week-long referendum achieves separation without unleashing renewed conflict, the pragmatists can rightly claim victory.

However, the legacy of secession will be a Southern Sudan with supersized expectations and no money to meet them. The vision of a new infrastructure springing up that allows Juba to shun Khartoum is a pipe dream. The challenge for the international community is to find a way to support a new state whose citizens believe it is richer than it is. This will need a more sophisticated approach than bankrolling rampant corruption and patronage which has so far been used to hold the fractious south together. The real test for the state builders starts now.