Congo has endured a near-constant state of war and chaos over the past 15 years. Its fate has been inextricably bound with its tiny neighbour, Rwanda, where in 1994 a Hutu extremist regime killed 800,000 Tutsis in the last genocide of the 20th century.
Tutsi rebels drove the extremists from power and sent more than a million Hutu refugees fleeing into Congo (then Zaire). The refugee camps in Congo became armed bases from which Hutu extremists could continue the war against the new Rwandan government.
In 1996, Rwanda moved against the camps and invaded Congo, eventually taking the capital, Kinshasa, and installing Laurent Kabila as president. But Kabila proved less compliant than Rwanda had hoped in the war against Hutu extremists.
Rwanda invaded again in 1998, leading to a prolonged war that drew in the Angolans and Zimbabweans on Congo's side, while Uganda and Burundi lined up with Rwanda.
A shaky peace agreement in 2002 saw the withdrawal of foreign armies from Congo, although local rebel groups tied to the Rwandan government continued to control much of the east of the country.
Hutu extremists there launched a new armed group, the Democratic Forces for the Liberation of Rwanda (FDLR), many of whose leaders had overseen the genocide in Rwanda.
A bulwark against them was warlord Laurent Nkunda, leader of a rebel faction, the National Congress for the Defence of the People (CNDP), its declared aim the protection of local Tutsis. But the Congolese government viewed Nkunda, who has been accused of war crimes, as a tool used by Rwanda to continue to destabilise eastern Congo.
Then came a change that caught many by surprise. A year ago an internal insurgency threatened not only Joseph Kabila, who had succeeded his father as president, but also Paul Kagame, the president of Rwanda. The pair overcame past enmity to announce a joint mission aimed at destroying the FDLR.
As part of the deal Nkunda was put under house arrest in Rwanda while his troops were "integrated" into Kabila's government army.
Controversially, this army is receiving the support of Monuc, the UN peacekeeping mission, in ongoing operations against the FDLR.
