Drawing on dramatic footage, previously confidential cables and interviews with U.N. and U.S. officials, FRONTLINE investigates how months earlier the U.S. and U.N. had been warned by a key Rwandan informant about the coming slaughter. Despite the warning, the West didn't try to prevent it. And once the genocide started, didn't try to halt it. In just 100 days, the Hutu majority of Rwanda murdered an estimated 800,000 of their Tutsi countrymen--a rate of killing that was faster than the Nazis.

In its indictment of the West's failure to act, "The Triumph of Evil" chronicles significant points in the unfolding genocide. It shows how a U.N. peacekeeping force of over 2,500 was unable to protect Tutsis seeking sanctuary. How, as the massacres spread, the U.N. withdrew its force, abandoning Tutsi refugees. And, at a point when Rwanda was literally overflowing with corpses, the program shows how U.S. and U.N. officials still refrained from calling it genocide so they wouldn't have to get involved.

In candid, on-the-record interviews U.S. officials detail how the U.S. held many inter-agency meetings and struggled with a response to the slaughter. In the end, the Clinton administration hesitated to act because of the so-called Somalia Syndrome; a few months earlier a U.N./U.S. peacekeeping mission in Somalia ended with the deaths of 18 U.S. Rangers. The Clinton administration didn't want to be dragged into another African quagmire.

As Philip Gourevitch, an expert on the Rwanda genocide, bitterly notes at the conclusion of this report, the Clinton administration's failure to intervene in Rwanda "wasn't a failure to act. The decision was not to act. And at that, we succeeded greatly."