Khartoum, Sudan
FLANKED BY 18TH-CENTURY CANNONS, Sudan's presidential palace stands impressively on the bank of the Nile. At the main entrance, elaborately decorated soldiers stand sentry, toting AK-47s fitted with razor-sharp bayonets. Entering the main hall, you walk under two enormous elephant tusks and between two vintage five-barrel machine guns aimed directly at you. Welcome to Khartoum.

Here at the palace, Deputy Secretary of State Robert Zoellick sat down with the most powerful man in Sudan, First Vice President Ali Osman Taha. After their meeting on April 14 Taha took Zoellick on a palace tour, eager to show him the location of the most famous event ever to happen in that building: the killing and beheading of the British general Charles "Chinese" Gordon.

As the colonial governor in the 1870s, Gordon heroically fought to end the trade of black slaves by Sudan's Arab minority. A decade later, the British sent Gordon back to Khartoum to deal with an Islamic rebellion led by an ally of the slave traders who proclaimed himself the Mahdi, which is Arabic for the "expected one." The Mahdi's holy warriors overwhelmed the British, slaughtering Gordon in the palace. Although the precise circumstances of Gordon's death are disputed, Taha showed Zoellick the version depicted in the classic movie Khartoum, with Charlton Heston and Laurence Olivier. In the movie, Gordon stood, unarmed, atop a stone staircase as one of the Mahdi's holy warriors thrust a spear into his heart. Gordon's head was paraded around Khartoum atop a stake, a gruesome symbol of

Robert Zoellick managed to get out of Sudan with his head, but Sudan poses one of the most perplexing challenges to President Bush's inaugural vow to oppose tyranny around the world. For the past two years, Sudan's western Darfur region has been the setting of an orchestrated campaign of murder and pillage. Last fall, Colin Powell called the killings in Darfur "genocide." Estimates of the number killed vary from 70,000 to over 300,000. So many villages have been torched and plundered that it seems as if everyone in Darfur has taken shelter in refugee camps. Of 2.6 million people in all of Darfur, an arid region the size of Texas, more than 2 million live in the camps. This is one of the largest humanitarian crises of modern times.

In the best-equipped camps, survivors have sufficient food and safe water, but that's about it. Most people are afraid to return to their destroyed villages. After his meetings in Khartoum, Zoellick flew to the El Fasher airport in Darfur and visited a camp of nearly 100,000 refugees called Abu Shouk. Everyone I spoke to there told a similar story of military aircraft bombing their villages from the sky and "Janjaweed" attacking on the ground. Janjaweed--which means, literally, devil on a horse--is what the villagers call the tribal militiamen.

LAST YEAR, the African Union sent a small force of monitors to Darfur. About 2,000 African Union troops are now there to watch and document the killing, but not to stop it. African Union monitors have seen the destruction firsthand and have compiled thousands of photographs and witness testimony. Their files are overflowing with evidence backing up the endless stories of villages being bombed from the air by Sudanese military aircraft and pillaged from the ground by marauders on horseback. These photos, together with thousands of pages of testimony from refugees, have been shipped off to the International Criminal Court in anticipation of future war crimes trials. Some of the most graphic photos were taken by a former U.S. Marine captain named Brian Steidle who went to work in Darfur for six months as a contractor for the African Union.