FIVE WEEKS after Secretary of State Colin L. Powell described the killings in Sudan as "genocide," the slaughter continues unabated. Sudan's government, which is responsible for these crimes in the vast western province of Darfur, still sends its soldiers to attack civilians and has not reined in its murderous allies in the Janjaweed militia. On Oct. 4 U.N. Secretary General Kofi Annan declared that Sudan had made no progress in halting the killing and no progress in prosecuting killers either. A week later a U.N. official reported that 220,000 people had been driven from their homes over the past month, swelling the number of displaced people to something near 2 million.

The displaced people of Darfur have lost crops, livestock and tens of thousands of loved ones. Some subsist on berries in the countryside; the rest huddle in dirty camps, where between 6,000 and 10,000 people die monthly for lack of food, medicine and sanitation. The camps are encircled by the militia death squads, making them prisons without walls. Men who venture out are sometimes killed; women risk rape on their daily search for firewood. Nobody knows how many people have died so far, but the commonly cited number of 50,000 is certainly too low. The World Health Organization reported on Friday that 70,000 have died since March in the camps to which aid workers have access. That leaves out most deaths from malnutrition outside those camps, as well as most violent deaths. Eric Reeves, an independent Sudan watcher who has analyzed family death rates reported by displaced people, puts the total death count at 300,000.

In Rwanda's genocide 10 years ago, the West pretended it could not see what was at stake until after 800,000 had been massacred. In Sudan's slow-motion catastrophe, involving death by starvation as much as death by violence, the West has acknowledged what is going on yet refuses to respond with any urgency. Food has been trucked and airlifted to the camps for displaced people, but roughly a third of those in need still go hungry. A series of diplomatic efforts to rein in the violence has progressed at a snail's pace. The United Nations has passed two resolutions calling upon Sudan's government to end the killing, but neither involved credible threats of sanctions. British Prime Minister Tony Blair visited Sudan this month, but it isn't yet clear that the fresh promises he extracted from the government are worth more than previous ones.

The Bush administration and its allies need to look their responsibility in the eye. A genocide is occurring on their watch, and neither the United States nor any other powerful nation is managing to prevent it. It isn't enough to pass resolutions, issue condemnations and hope that history's judgment will be merciful; the test of the Bush administration and of European nations such as Britain and France will be whether they used their clout in the region to prevent genocide from happening. For weeks there has been talk of a deployment of African Union troops in Darfur, but the Bush administration has failed to exercise the leadership that might make this idea real. For weeks there has been talk of sanctions, but the Bush administration has not done everything it could to persuade the United Nations to get serious about them.

Meanwhile the killing continues.