Rebels trying to overthrow Sudan's Islamic regime are posing one of the biggest challenges in 13 years of civil war, thanks to new ties with the northern opposition and some apparent help from outside friends.
In the last three weeks, the rebels have swept through more than 10 towns. Wednesday, they reported they had captured two towns less than 20 miles from the strategic Roseires Dam, although the report couldn't be independently confirmed.
The gains appear to be fruits of an alliance formed last year between Arab northern opposition groups and the black Sudan People's Liberation Army (SPLA), which since 1983 has been fighting to keep Khartoum from clamping the hand of Islam on the animist and Christian south.
Analysts in the region believe that what has also helped the rebel onslaught is the military aid from Sudan's hostile neighbors Eritrea, Ethiopia, and Uganda.
"Reports indicate that foreign aid is vital," says Norman Aphane, assistant editor of the Pretoria-based quarterly Africa Inside.
The 30 million people of Sudan - which is about the size of the United States east of the Mississippi - have been at war with each other on and off since independence from Britain in 1956. Sudan is composed of about 550 ethnic groups that speak 100 languages. Culturally, it is almost two separate countries: the Islamic north and the black south. The southern SPLA rebels, led by John Garang, are fighting for more autonomy from the Islamic north and for potential oil revenue to remain in the impoverished south, rather than being diverted to the north.
The new fighting, which is spreading quickly along a 390-mile front, poses the biggest challenge yet to the Islamic government, which seized power from an elected one in 1989.
Most of new offensive, which began on Jan. 12, has been in the east near the Eritrean and Ethiopian borders. But Sunday, Sudan said it had attacked a rebel base near the southern border with Uganda. While analysts believe another front may be opening, the rebels deny it.
Eritrea, Uganda, and Ethiopia deny claims by Khartoum that they are taking part in the fighting. But the trio make no secret of its enmity toward the Islamic extremist government of Sudan's President Omar Bashir, which the US considers to be a sponsor of international terrorism.
Eritrea and Ethiopia have accused Sudan of sending commandos across the border to attack on their soil. Uganda has repeatedly complained about Sudan giving support to Ugandan rebels.
Ugandan President Yoweri Museveni, in a recent interview with The Financial Times, made clear his animosity toward the Khartoum regime by calling for Sudan's civil war to be declared a colonial conflict by the Organization of African Unity so that other African countries could provide military support to the rebels.
Regional analysts believe that Washington is anxious to bolster the three so-called front-line states to serve as its proxy against Khartoum. They point to plans revealed late last year to provide $20 million in surplus "nonlethal" military equipment to the three.
A spokesman at the US State Department says the aid has not yet been delivered.
The equipment, which analysts believe would trickle down to the Sudanese rebels, was to include materials such as tents and radio communications, which are vital when waging guerrilla warfare.
However, while apparently wanting to strengthen the front-line states, the Clinton administration is quietly allowing US oil deals in a country that it accuses of supporting terrorism.
The US has exempted Sudan from the 1996 terrorism act that bars transactions between American corporations and countries it deems pariahs.
While the rebels now advance, the Khartoum regime is reportedly finding it hard to muster the popular support necessary to recruit more volunteers for the front.
The war-drained economy is in terrible shape. Hardships are only going to get worse with a hike in gasoline prices due to the increased demand to truck new volunteer soldiers to the front.
These volunteers are not among the country's best-armed or trained forces. The the regime runs the risk that if body bags come back in large numbers from the front, already low popular support will be eroded even further.
Calls by Sudan on Islamic countries for help have so far apparently not produced the needed support. The one loyal ally is Iran, whom the rebels accuse of providing military aid to Khartoum.
The regime is unlikely to get help from nearby, as it is deeply unpopular with most of its nine neighbors. Among its detractors is Egypt, which is still angry over Sudan's presumed involvement in an assassination attempt on President Hosni Mubarak in June 1995 and Khartoum's subsequent refusal to hand over three men accused of being involved in the act.
Egyptian Foreign Minister Amr Moussa implicity warned Iran on Sunday, saying his country would "not stand idle" if foreign powers intervened in the Sudan conflict.