On the ground in Sudan

It has been nearly two years since fighting broke out in the Darfur region of the East African country of Sudan, killing tens of thousands, and the death toll continues to rise. The United Nations estimates that approximately 1.6 million people have been left homeless. Three weeks ago, the Arab-dominated Sudanese government and predominately Black rebel fighters agreed to a cease-fire, but tensions remain high and fighting continues. What are the roots of the conflict, and what can be done to staunch the bloodshed?