Why Sudan's civil war is so intractable three years on

Today marks three years since the start of Sudan's civil war. Thousands are believed to have died and as many as 14 million have been forced to flee. In Berlin Wednesday, an international conference hoped to encourage peace talks - though neither side had representatives present. The World's Host Carolyn Beeler learned more from Alex de Waal, the executive director of the World Peace Foundation at the Fletcher School of Law and Diplomacy at Tufts University.