But many attempts to end Congo's conflict have failed, in part because wars that appear to be all about ethnicity are also about business. Hutu rebels claim to be taking refuge from a vengeful Rwandan President Paul Kagame, who blames them for the 1994 genocide of more than 800,000 Tutsis. But the rebels have built a militia by controlling the trade in tin, tungsten, and coltan.
The rebels "are not in any areas that don't have minerals," says Joseph Mukind Kakez, a top government official in eastern Congo. He also blames his own government for its inability to control armed groups as well as ordinary Congolese, who buy and sell minerals from the armed groups, giving them the money to feed and rearm themselves and keep Congo's long conflict brewing.
"People ask: Who supports the armed groups?" he says. "It is we Congolese ourselves."
Efforts to stem the crisis
Tens of thousands of displaced Congolese are continuing to stream into Goma as General Nkunda's forces remain on the edge of the city. British and French foreign ministers arrived in Goma over the weekend to appeal for calm and to pledge their support for a humanitarian response to the estimated 1.4 million people displaced by conflict.
An aid convoy, the first in a week, arrived on Monday to provide food for 250,000 of those people, as UN negotiators pleaded with both the Congolese government and Nkunda's forces to find a peaceful settlement to the crisis.
Nkunda says his men will disarm and integrate into the national Army, as soon as the government expels the Hutu-led Democratic Liberation Forces of Rwanda (FDLR) from Congolese soil. The government says Nkunda must disarm first.
"They [the FDLR] will not leave the Congo because they have access to minerals that they can buy and sell; it is a problem to stop them," says Juvenal Tembeze, provincial chief for the ministry of mines in South Kivu Province. "For the FDLR, it is a matter of life and death. If you forbid them access to the mines they are ready to kill, and they will take it out on the civilian population."
Congo's riches: a curse?
Given its immense natural resources, the Congo should be one of the richest countries on earth, with an estimated $300 billion worth of timber, gold, diamonds, cobalt, copper, tin, and coltan. Nearly 80 percent of the world's known reserves of coltan – a key metal used in cellphones and video games – come from Congo. Yet instead of a blessing, Congo's riches have become a bane.
The crisis – funded by the world's insatiable need for mineral resources – is not an easy conundrum to solve. US sanctions forbid high-tech companies from buying Congolese coltan, for instance, but sanctions don't affect coltan purchased in neighboring Rwanda. Rwanda is not a coltan-producing country, so its coltan mainly comes from Congo, illegally.
More targeted sanctions, proposed by the UN in a 2002 report, aimed at the armed groups themselves, are similarly problematic, government officials and private traders say.
"How can I tell who is legitimate?" asks Mark Patzelt, an exporter of minerals, based in Goma. "When it gets to me it's changed hands so many times, and the trader will tell me anything I want to hear, that he bought from legitimate sources. I've never seen a list of people I'm not supposed to buy from. I could cut out a complete region, but no one has told me where.
"Until the Congo government wakes up and starts paying people [especially government employees a decent wage, to remove the incentive in illegal mineral trading] – it will be impossible to separate the black sheep from the white."
Mr. Patzelt may have difficulty distinguishing where his minerals come from, but even individual traders like Olivier Mugaruka and Bashi Makala – who drive out to mining villages and buy directly from the miners – say it is difficult to tell who is a member of the FDLR.
Traders such as himself and Mr. Mugaruka say they rarely go into FDLR areas because of the risk, but when they do, they bring items such as salt and flour and cooking wares to sell in FDLR-controlled villages.
They pay a "tax" to the FDLR for the right to trade in FDLR areas, and they carry the constant fear that they might simply be looted of all their goods, including the minerals they have purchased to bring back to Bukavu.
"You have to understand that when the FDLR loot, they become wealthy, and the people who are looted become poorer," says Mr. Mugaruka. "We have no choice [but to trade in rebel-controlled areas]. It is up to the international community if they want to push them out."
A mining village caught in the middle
At the end of a drenching afternoon rainstorm, the miners in the tiny village of Luntukulu head back down into the flooded holes in the ground, scraping out chunks of casiterite, a kind of tin.
It's dangerous work – earning them about $30 a week – and risky not only because these holes in the ground have a tendency of collapsing. It's dangerous, too, because of the presence of armed groups who control the mining trade in North and South Kivu, and who keep the region one of the poorest, most war-torn spots on earth.
As the afternoon sun comes out, villagers point to the nearby village of Kakayi, just three kilometers away, an area under control of the FDLR. The Rwandan rebels used to raid Luntukulu, villagers say, but stopped after a short offensive by local Congolese Army commanders brought a truce in 2006.
Now, the FDLR are allowed to control the trade in minerals in Kakayi, and Congolese Army troops take a 500-franc- ($1)-per-person monthly fee to provide security to the miners in Luntukulu.
"The soldiers look after our security," says one of the miners, nervously eyeing the local Army checkpoint, where Congolese soldiers are becoming drunk on beer. Asked if the security fee is official, the miner shrugs. "It is abnormal to have money in hand, and the soldiers have nothing. That is why we give."