In late February 2004, Janjaweed militias and Sudanese government forces waged a three-day, coordinated assault on Tawila, a village in northern Darfur. Government aircrafts destroyed buildings, while the Janjaweed broke into a girls’ boarding school, forced the students to strip naked at gunpoint, and then gang-raped and abducted many of them. Video footage shows fly-covered corpses strewn among the village's smoldering ruins. And giving orders and distributing weapons during the siege, eyewitnesses say, was Sheikh Musa Hilal.

Saviors and Survivors: Darfur, Politics, and the War on Terror

By Mahmood Mamdani

(Pantheon, 398 pp., $26.95)

The Responsibility to Protect: Ending Mass Atrocity Crimes Once and For All

By Gareth Evans

(Brookings, 349 pp., $24.95)

I.

In the summer of 2007 , Mahmood Mamdani found himself at a meeting of activists and politicians, listening to sentiments that had by then become quite common among a certain class of politically active Americans. The speakers were calling on the United Nations to send peacekeepers to Darfur. Fed up with the inability of African Union troops--who were already on the ground in western Sudan--to stop the ongoing bloodshed, they insisted that U.N. forces could do better. The United Nations, explained one politician, echoing a view you could have heard on any number of college campuses at the time, would grant "mercy" to the people of Darfur.

On Wednesday, Barack Obama appointed retired Air Force Major General J. Scott Gration as his special envoy to Sudan. In 2001, when the envoy position was first created, the job entailed brokering a peace deal between Khartoum and rebel groups in the south. It subsequently mutated to include halting Darfur's genocide and reversing President Bashir's expulsion of humanitarian aid workers. So, what does Gration's appointment mean for Darfur policy now?