Sudan’s complicity in the humanitarian disaster in Africa is beyond doubt. Khartoum has, according to United Nations observers, aid workers and human rights activists, armed and encouraged the Janjawid, the Arab militias now raping, murdering and terrorising black Muslim villagers in the western Sudanese province of Darfur. Ministers in Khartoum at first denied all reports of atrocities. Then they blamed uncontrolled local warlords while refusing entry to aid convoys for the refugees. Now they have at last agreed to start “peace talks”, but see these as merely a tactic to delay outside intervention and allow the government-backed militias to complete the “ethnic cleansing” of an area larger than France.

It is time to confront such lies and hypo-crisy more forcefully. Kofi Annan, the UN Secretary-General, has sent an envoy to Khartoum to see whether Sudan is living up to promises of intervention to curb the massacres and atrocities. By all accounts, virtually no action has been taken beyond the sentencing to a six-year jail term of ten token militia prisoners accused of looting. Amnesty is still daily alleging the abduction and gang-rape of women as young as 8 and as old as 80. Diana Abbott, the Labour MP, tells The Times today that the situation is “Ethiopia all over again”, with at least 2.2 million people directly affected by violence and “almost indescribable” human carnage.

Yet much of the world still looks away. Too many European leaders, normally so quick to take up the plight of groups they see as victims of globalisation or Western-backed dictators, have remained virtually silent. Britain, admittedly, has denounced the killings, worked to secure entry routes for aid and sent more emergency rations than any of its European Union partners. But Sudan’s neighbours have been culpably negligent. The Africa Union, called into being largely to prevent another Rwanda, has muttered about fresh talks with Sudanese government officials and Darfur rebels, but done little more than reflect the impotence and indifference of most African governments to what is amounting to another genocide.

It has been left to Washington to voice the world’s outrage and warn Sudan to halt its brutalities. Colin Powell, the US Secretary of State, has made clear America’s readiness to back moves in the United Nations to use military force to halt the attacks. Washington has called for a global arms embargo against the Janjawid and their allies, and would be ready to support calls by Human Rights Watch for sanctions against all Sudanese officials supporting the militias. Those who denounce the Bush Administration as the enemy of Islam have yet to admit that this same Administration now offers the best hope of halting the slaughter of defenceless African Muslims in Darfur.

Apologists for the repressive Islamist Government in Sudan try to explain the Darfur killings in terms of traditional enmities and competition between nomadic Arabs and village-dwelling Africans for scare pastures when overgrazing and the encroachment of the Sahara are threatening the lives of all. They point to the differentiation between tribes in the north of Darfur and those in the south, the shifting alliances and the political challenge of separatists demanding a better deal from Khartoum.

Such sociology is superfluous. Whatever the causes of conflict, the systematic violence and ethnic cleansing belie all explanation or excuse. Sudan claims that its accusers are “distorting Arab culture” and driving a wedge between ethnic groups. This is a mendacious irrelevance. What the world is belatedly trying to do is save a people from annihilation. There is little time left.