The United Nations is still reluctant to intervene with force in Darfur and a strategy of pressure on the government of Sudan is being tried first.
There are precedents of intervention to protect refugees
The Security Council passed a resolution on 30 July giving Sudan 30 days in which to disarm the Janjaweed militia and bring human rights violators to justice.
The resolution says that, if Sudan does not act, it will consider "further actions, including measures as provided for in Article 41 of the Charter of the United Nations on the Government of Sudan."
Article 41 does not authorise force but it does authorise economic measures such as the "complete or partial interruption of economic relations and of rail, sea, air, postal, telegraphic, radio, and other means of communication, and the severance of diplomatic relations."
Any armed intervention is much further down the road. And if it is ever authorised, it is likely to be aimed mainly at securing humanitarian aid.
And before any force was sent, the agreement of the Sudanese government would be sought first.
Only if things got much worse would intervention against the wishes of the government of Sudan be considered.
In the meantime, the African Union is now talking of sending a force of 2000 there (with troops from Nigeria and Rwanda), with the government's agreement, to oversee a shaky ceasefire between government and rebels.
It is unlikely that Western governments will react over Darfur as they did over Kosovo in 1999 when Nato planes bombed Serbia.
The two crises have some things in common - a humanitarian catastrophe, militias attacking the population, a central government unwilling or unable to rein them in and guerrilla actions against government forces.
But there are important differences.
The Darfur region is vaster and more remote than Kosovo, which sat conveniently not far from Nato air bases in Italy.
In addition, a crisis in Africa has to be of particularly large proportions before the outside world wants to get involved beyond providing aid.
That was evident in Rwanda, a crime on an even greater scale.
There is also considerable reluctance in Western capitals to get engaged in another direct confrontation with the government of a largely Muslim country.
There are precedents for using troops not to attack a central government but to provide security for refugees
Sudan itself is aware of that and is hinting at the potential for regional destabilisation if there is military aggression.
The basis for a limited intervention would be that international law now recognises the right of other countries to intervene somewhere on humanitarian grounds. The Security Council would probably be asked to approve such a mission.
If thousands more die and the government of Sudan does nothing or nothing effective, then limited action might become more extensive, though the idea of Western troops tackling the militias in the desert is not one which appeals to governments or military planners.
In the meantime, the strategy is one of getting aid to the distressed and dying and of putting pressure on the Sudan government by threatening sanctions.
Very few governments want to consider what to do if all this fails
There are precedents for using troops not to attack a central government but to provide security for refugees. After the Gulf War in 1991 the US, the UK and others set up safe areas for the Kurdish refugees from Iraq who flooded over the mountains into Turkey.
Planning is already under way. The UK is thinking about a joint civilian-military team, according to Foreign Secretary Jack Straw, who is going to Sudan soon.
Development Minister Hilary Benn, who has played a leading role for the British government over Sudan has outlined a multi-part plan - get money for aid, provide that aid, ensure security for it, pressure the Sudanese government to provide safety for the people and finally get a political settlement of the underlying rebellion.
The European Union as a whole has now added its voice to the warnings.
UN Secretary General Kofi Annan has also been to Sudan. The government there is in no doubt about world opinion.
In the background the US Congress has passed a non-binding resolution declaring that this is "genocide." If the US government agrees - and it has yet to - such a finding would set off action under the Genocide Convention, though exactly what is not certain.
"Those doing the killing need to understand that the world is changing. We have international courts to hold human rights criminals accountable. The days of impunity are ending," said Congressman Ed Royce, chairman of the House sub committee on Africa.
So there is plenty of pressure, with the threat of more to come.
Very few governments, however, want to consider what to do if all this fails.
It all goes to show that there is no clear way of dealing with such a crisis.