While no one knows for sure how many people have died in the conflict in Darfur, western Sudan, more than 2.6 million are suffering because of it and in urgent need of assistance, write Kofi Annan and Alpha Oumar Konare.
Villages have been burnt, crops uprooted, men murdered, women raped, children abducted.
Some 1.9 million people have been displaced from their homes within Sudanese territory. Others are still at home but prevented from planting the crops on which their lives depend. If food does not soon reach them, they too will be forced to go in search of it, swelling the already overcrowded camps.
For a period, crimes against civilians in Darfur were not on the front pages. But for well over a year they have been. That it took intensive coverage in the world media to prompt action is a reproach not only to Sudan, but to the whole world. Even today those who are trying to bring the crisis in Darfur to an end do not have the kind of support they need.
Our two organisations have come together to prevent further suffering.
The United Nations is in the lead in bringing relief to the victims, and in seeking to end impunity for those who have committed the most heinous crimes.
The African Union is in the lead in providing security on the ground, and in efforts to revive political negotiations which alone can bring lasting peace and which are now scheduled to resume on June 10th in Abuja, Nigeria.
In recent months the situation has stabilised, and fewer large-scale crimes have been reported. A massive UN-led humanitarian operation is under way, with over 10,000 humanitarian workers (mostly Sudanese) delivering food, water, shelter and other life-saving relief to up to 1.8 million people. In the areas where AU troops are on the ground their heroic efforts have made a real difference: people are less exposed to predatory violence, many have returned to their villages, and attacks have decreased.
The humanitarian situation is thus undoubtedly better in some areas than it was a year ago, but access remains limited, the harassment of humanitarian workers has increased, and insecurity remains unacceptably high.
Hundreds of thousands of war-affected people are still not receiving the help they need, and the AU troops are as yet far too few to deploy throughout the whole vast territory.
Relief workers are often harassed by local authorities, and sometimes even attacked, kidnapped or threatened with violence. Non-governmental relief workers from abroad find it increasingly hard to obtain visas.
And trucks delivering aid are hijacked, often by rebels. Early this month two drivers for the World Food Programme were killed in separate incidents. As a result, aid does not get through to many of those who most need it.
The international response is thus falling short in two lethal ways: another $350 million in aid is needed to help more than three million people survive the rest of this year, and more troops, police, aircraft and other transport, training and logistical support are needed to enable the AU to protect the population in much of Darfur.
As part of our efforts to address the crisis, we have jointly convened a donor conference in Addis Ababa: to give the rest of the world - especially the wealthy countries that have the means to contribute, and whose media and public opinion have been most vocal about the need to halt atrocities in Darfur - an opportunity to rally round and give practical support to the Africans who are actually doing something on the ground.
This conference will complement the one held in Oslo last month, at which $4.5 billion of aid was pledged to Sudan, mainly to support the fragile peace which has at last been achieved between north and south after a 21-year civil war.
Indeed, Darfur can only benefit if the rest of the Sudan is at peace, and if the new government of national unity (due to take office in July) leads the whole country in a new, more inclusive direction.
Thus the 10,000-strong peacekeeping force which the United Nations is now deploying in the south will help make peace viable throughout the country, including Darfur.
But action is urgently needed in Darfur itself, on three fronts: The humanitarian effort must be fully funded, and safe access for relief workers - both inter- and non-governmental - must be fully guaranteed by all parties.
The AU force must be expanded without delay, and bolstered by logistical and financial support, so that it can provide real security throughout Darfur, allowing the people to return to their homes and resume cultivating their crops.
African states that have promised troops must provide them promptly, and donors must provide the means needed for those troops to deploy. Both the government and the rebels must bring their forces and allied militias under full control, and ensure that they fully respect the ceasefire and humanitarian law.
And the parties to the conflict must negotiate a political agreement offering solid guarantees for lasting peace. The AU and the wider international community can and must help. But in the end peace will only be made, and kept, by the Sudanese people themselves.
Kofi Annan is secretary general of the United Nations; Alpha Oumar Konare is chairperson of the Commission of the African Union