April 7 marked the sixth anniversary of the Rwandan genocide, one of the most shameful acts of political cowardice in recent history. Many uncertainties still linger over the events that began that day, but what we know is enough to judge the behavior of the participants as evil, and the reaction of others as disgraceful.

On April 6, 1994, unknown individuals -- now suspected to have been Tutsi guerrillas -- shot down the plane carrying Rwandan President Juvenal Habyarimana. The next day, Hutus went on a rampage throughout the country, slaughtering between 500,000 and 800,000 Tutsis and moderate Hutus. Allegedly, the genocide had been planned months in advance.

The killings sparked international outrage, but the United Nations did not intervene. Indeed, foreign troops were withdrawn when the violence began. The extent of the U.N.'s knowledge of the situation in Rwanda is another subject of dispute. Reportedly, the organization had been warned several weeks before that a massacre was imminent. Eventually, a group of rebel Tutsis ousted the Hutu extremists and installed their own government.