Registration opened in Southern Sudan on Monday for a vote that could split Africa's largest country. Some fear it could reignite the continent's longest-running civil war, but the United States is trying to prevent that.
U.S. Sen. John Kerry traveled to the Sudanese capital Khartoum twice in the past several weeks to persuade the government to honor the coming votes on secession. So far, it has not been an easy sell.
Western diplomats in Khartoum worry that violence could flare along the country's volatile North-South border.
"In the civil wars that have happened here, 2 million people died -- that is a horrific humanitarian crisis," says retired U.S. Ambassador Princeton Lyman. "If the war comes again, it will happen again."
Lyman, who is helping lead North-South talks on a host of issues, says another war in Sudan would be costly in many ways.
"The United States should not only be concerned from a humanitarian point of view -- quite frankly, we'll be spending billions of dollars on relief," Lyman adds.
The North and South battled each other for two decades over various issues, including resources, religion and ideology. Most of the civil war's victims died of starvation and disease.
As part of a peace agreement the U.S. helped broker in 2005, South Sudan will vote Jan. 9 on whether to break away from the North.
But the road to the referendum is a minefield of volatile issues, including how to divide oil money and even the waters of the Nile.
On his latest trip, Sen. Kerry (D-MA) offered Khartoum a deal on behalf of the Obama administration: Support the referendum and resolve control over a disputed area called Abyei, and in exchange, the U.S. would take Sudan off the list of countries that sponsor terrorism by this summer.
The response so far?
"Obviously, they always like to hear more," Lyman says.
In fact, Sudanese officials disparaged the offer in print interviews.
Former Sudanese Finance Minister Abdul Rahim Hamdi doesn't speak for the country's ruling National Congress Party, but he is a member, and his words reflect the thoughts of many in the Sudanese capital.
"Let me be very candid with you," he says. "We look to this as a joke."
Hamdi says if the South votes to leave -- as expected -- Sudan will give up a huge chunk of land and, with it, the majority of its oil. He says the government wants more than just the removal of its name from a list.
"We want actually a normal political and economic relationship with the United States," Hamdi says.
Washington and Khartoum have been at odds for years. Sudan supported the 1990 Iraqi invasion of Kuwait and also played host to Osama bin Laden during that decade.
Hamdi says full diplomatic relations would have many benefits, including U.S. investment and technology.
"American technology is far superior to others, especially in oil and telecom," he says.
Khartoum also is looking for help in other areas, including relieving its $39 billion in debt and lifting the indictment of President Omar al-Bashir. Last year, the International Criminal Court issued a warrant for the arrest of al-Bashir on charges of war crimes related to the killings in Western Sudan's Darfur region by the government-backed Janjaweed militias.
"But we don't control that," Lyman adds, "and we've said that."
Lyman says he worries about violence next year but a little less so than he did a few months back. He says that's because the South looks increasingly determined to hold the referendum and probably vote for secession.
And the North is struggling to come to grips with that.