It may take another half century to get the country to the point of being functional and safe, as the conditions are atrocious and corrupt. But giving up would just mean that even more people will die and suffer. If other major players in the world, like China, step up and take a stand, maybe there will be progress.
The UN has been at this since before 1999. They were originally there to keep the peace after the second Congo war, but remained there to monitor several ethnic conflicts that arose since then. India is currently the largest contributor of peacekeeping forces, but they are scaling back their military commitments to the mission. There has also been several instance of corruption that have curtailed the UN's efforts as well.
I don't think a place like that could ever be stabilized, the culture kids grow up in, and the lifestyles they experience. Being a realistic person I don't think they can civilize themselves, mostly because of lack of resources. Also, the economic situation is horrible, and sometimes money can turn people into animals.
While I agree it is theoretically possible, I think we're too far gone here. The area has too long a history of it and its people being abused for resources, it's such a part of the culture there now that it's almost unfathomable how companies capitalizing on the area can withdraw at the same time that a stable governing body is put into place. There are so many things that could go wrong and it's an area that doesn't take a lot of provocation to get set off at this point, the scenario would have to play out too perfectly and everybody would have to play nice. It's almost an impossibility.