The United Nations Security Council has passed a resolution to send a 26,000-strong peacekeeping force to Sudan's war-torn western region of Darfur.
Sudan's government and the pro-government Arab militias are accused of war crimes against the region's black African population, although the UN has stopped short of calling it genocide.
The hybrid UN-African Union force will boost the 7,000 AU force already in Darfur, who have failed to halt attacks on civilians which has led to some 2m people living in camps.
What is the difference between the new and old force?
Firstly, the hybrid force is much bigger, so it should be more capable of ending attacks.
However, Darfur is the size of France, with little infrastructure such as roads, railways or power. So critics say even 26,000 soldiers and police will be unable to cover the whole region.
Secondly, the hybrid force has a stronger mandate, so it will be able to intervene more forcefully to protect civilians under attack and to ensure that aid workers can operate safely.
However, the wording of the latest resolution is already being interpreted differently by different sides.
The resolution says the peacekeepers can use force "to protect civilians without prejudice to the responsibility of the government of Sudan".
Sudan's government seems to take this to mean the peacekeepers should not use force too often but western diplomats say it does not mean they need to ask the government's permission before intervening.
Thirdly, the involvement of the UN is expected to mean that the force is better equipped - in military terms, as well as transport such as planes and helicopters to move around such a large area.
It should also mean that the force is properly funded - some AU peacekeepers have complained that they were not being paid.
When will the force be deployed?
The first extra troops and police will be sent in October, but most troops will not arrive until next year.
So it will not change much on the ground very soon.
Most of the troops are set to come from African countries - to placate Sudan's concerns about Western interference in its territory.
It has always said the problems in Darfur have been exaggerated for political reasons, especially by the US.
But the resolution spells out that the UN is in charge of the force and there is a single chain of command.
Why has it taken such a long time for the UN to act?
Sudan's government strongly insisted that the AU force could do the job - although Sudan's critics say this was because it was happy for the peacekeepers to be so weak.
Sudan said that allowing a UN force would mean Western recolonisation, even though there are already UN peacekeepers in the south, following the end of a separate conflict.
China - a veto-wielding member of the Security Council with strong economic interests in Sudan - backed its ally.
Together, they ensured that the resolution was not as strong as it was in its original form. Haggling over the precise wording took many months before its was acceptable to all sides.
The US and others had wanted the force to be able to disarm militias and pursue and arrest suspected war criminals indicted by the International Criminal Court but these sections were removed.
Furthermore, the resolution does not threaten sanctions if Sudan does not comply with it.
So is this is end of the conflict?
Not yet, for sure, but it could be a major step forward.
Even after all 26,000 troops and police are deployed, they will not be able to stop the rebels, army and pro-government militias fighting if they really want to. There must be a peace for them to keep.
Further talks are being organised between the government and the various rebel groups.
But their internal division has made reaching an overall agreement extremely difficult, so the first step might be for them to reach a common position.