There can be no more delays. It is time to act over the slaughter in Sudan

Ten years ago, the world watched genocide in Rwanda unfold on our television screens. The international community stood by and did virtually nothing. In the months which followed - as the scale and brutality of the pitiless slaughter became clear - the air grew thick with "never agains". In October 2001, when Tony Blair sought to make the case for invading Iraq, he reminded us of Rwanda and the determination of the rest of the world that nothing like that must ever happen again.

Ten years ago, the world watched genocide in Rwanda unfold on our television screens. The international community stood by and did virtually nothing. In the months which followed - as the scale and brutality of the pitiless slaughter became clear - the air grew thick with "never agains". In October 2001, when Tony Blair sought to make the case for invading Iraq, he reminded us of Rwanda and the determination of the rest of the world that nothing like that must ever happen again.

So what has happened to the notion of liberal intervention? Cynics might suggest it has become mired in the quagmire that now is Iraq. But reports yesterday suggested that the Prime Minister has asked for officials to draw up plans for possible military intervention in Sudan where up to 30,000 people have been killed - and a million more driven from their homes - in a campaign of ethnic cleansing by Arab militias against the black population in Darfur in the remote west of the country. Perhaps, after all, there was more to liberal intervention than a mere fig-leaf to cover a decision not to alienate our allies in the United States.

Downing Street yesterday denied that military intervention was imminent. It may well be that the reality of British troops on the ground is premature, but the threat of it is timely enough. For the evidence is that the Janjaweed militia responsible for the campaign of murder and terror is backed by the unpleasant government in Khartoum.

Independent aid agencies and human rights groups have collected testimonies of the Sudanese army looking on as the militia torched village after village in Darfur and terrorised its people. Men in official army uniforms have taken part in the mass rapes of black girls and women - aged eight to 80 - in front of their defenceless menfolk. The Sudanese authorities have even allowed the Janjaweed to follow the hapless refugees across the border into neighbouring Chad to drive them from the ramshackle shelters of scrappy cloth they had erected in rapidly growing refugee camps there. The terror campaign has been going on for more than a year now.

The response by the rest of the world has, so far, been dilatory. The US Secretary of State Colin Powell went to Khartoum and wagged his finger a few weeks back; this week, he has added that the international community is "completely dissatisfied" with Sudan - a pretty lame response in the face of the blatancy of what is taking place. The United Nations secretary general, Kofi Annan, yesterday said that Sudan had made little progress in disarming the Janjaweed as was promised when he visited Khartoum a fortnight ago. It is clear, he said yesterday, that serious crimes have been committed, and there has been gross and systematic abuse of human rights.

None of this is enough. Faced with the characteristic intransigence of the Sudanese government, the civilised world must now act. The time has come to suspend certain lines of aid to Khartoum and to target the ruling élite with sanctions, including travel bans and the seizure of personal assets held abroad. Donor governments should negotiate with neighbouring countries like Libya and Chad to set up alternative routes for the humanitarian aid now needed by two million Sudanese people.

Through the UN Security Council, which is considering a draft resolution to impose sanctions if the violence continues, the rest of the world should impose a no-fly zone in Darfur where government planes have been bombing villages. It should authorise planning for military intervention, led by the states of the African Union, to create safe havens for internally displaced people, and to disarm the Arab militias. And the UN should set up a war crimes investigation unit to act as a deterrent to further atrocities.

For the 30,000 people who have died already, all this comes too late. But there is still time to stop terror from turning into full-blown genocide - and to prevent Darfur 2004 from joining Rwanda 1994 in the litany of international shame.