The African Union has played dual roles in the Darfur conflict: chief mediator for talks between Sudan's government and Darfur's rebel groups, and overseer of an April 2004 cease-fire signed by rebel forces and the government.

But because of its small size and stretched resources, the 7,000-member force was unable to halt the mass murder, rape and other violence that aid groups and international observers contend has characterized the Darfur crisis since it began in 2003.

In July 2007, the U.N. Security Council unanimously adopted a resolution authorizing a joint United Nations and African Union peacekeeping force of up to 26,000 troops and police to the western Sudan region of Darfur. But as of June 2008, just under 10,000 peacekeepers had been deployed.

A number of factors contributed to the delay, including the reluctance of the international community to supply equipment such as helicopters, stalling by the Sudanese government, and a lack of basic infrastructure such as roads, accommodations and clean water for the influx of troops, said former U.N. special envoy to Darfur Jan Eliasson in a Feb. 8, 2008 NewsHour interview.

The African Union's role in the Darfur crisis stems from an October 2004 AU Peace and Security Council mandate authorizing troops in the region to monitor the cease-fire.

The mandate may have marked the first mistake in the organization's planning for the Darfur mission, according to observers.

Rather than follow the recommendations of its own assessment team to enter Darfur in the role of protector, the AU's mandate called only for troops to serve as monitors of the crumbling cease-fire, a concession insisted upon by the Sudanese government. The government has been accused of financing and supplying the militia responsible for much of the violence in the crisis. It has fought to keep interference from outside the country and continent at a minimum.

"The initial idea of operations for the AU force was deeply flawed from the outset," according to the ICG's John Prendergast, who visited Darfur on three separate occasions in 2005 and 2006. "By authorizing a mandate that only was focused on cease-fire observation rather than protection of civilians, it minimized the objective of the force and rendered it largely irrelevant."

The AU mandate calls for troops to "monitor and verify" cease-fire violations and for troops to protect civilians only under "imminent threat," but leaves the main protection of civilians to the government that is accused of terrorizing them.

"AMIS shall ... perform the following tasks ... protect civilians whom it encounters under imminent threat and in the immediate vicinity, within resources and capability, it being understood that the protection of the civilian population is the responsibility of the [Government of Sudan]," the Oct. 20, 2004 mandate read.

According to Prendergast, by failing to stand up to the Khartoum government, the AU gave up responsibility to quell the violence, which has led to an estimated 200,000 deaths.

Originally numbering only about 150 in 2004, AU forces in Darfur grew to about 7,000 by early 2006. The soldiers were dispersed throughout the region in small units at the displacement camps that house Darfur's more than 2 million refugees.

Despite not having the authority to go out of their way to protect civilians, aid groups in the region cited instances of AU troops voluntarily defending women and children at the camps, where reports of militias gang raping those who leave the camps for food and water are common.

A lack of resources -- money, weapons, even vehicles to get them into the field -- has hindered their mission, and at times, peacekeepers were outnumbered and overcome by militia forces.

The African Union's efforts to broker peace talks in the Darfur crisis in 2004 and 2005 also hit roadblocks. Union mediators were unable to overcome infighting among the two main rebel groups negotiating with the government.

While some critics blamed the AU's inability to end the crisis on its failure to stand up to the Sudanese government, others said growing pains were to blame.

"The truth is this crisis happened before the African Union was ready. They're new in the sense that they're successors to the Organization of African Unity. They had developed a five-year peacekeeping program that would have peacekeeping brigades available to move into an African crisis ... one in the east, one in the west and so on, but they were probably 12 months into a five-year plan when [the Darfur crisis] happened," Charles Snyder, the senior representative on Sudan for the State Department said, in a September 2005 interview.

Founded in 1999, the AU serves as the continent's mini United Nations. It is made up of 53 African nations.

-- By Kristina Nwazota, Online NewsHour