But most analysts believe the origin of the rebellion is a fight over Congo's vast mineral wealth, a good chunk of which is found in the North Kivu province where Goma is the capital. Starting in April, the fighters seized a series of small towns and villages in North Kivu, culminating with the capture on Nov. 20 of Goma, a population hub of 1 million and a key, mineral trading post.
Months before taking Goma, the rebels steadily made their way down the road from Kibumba, and in the weeks just before the fall of the regional capital, that artery was swarming with rebel soldiers and punctuated by checkpoints. By contrast on Friday, that same road was remarkably empty, showing no signs of rebels retreating, as they had earlier promised when they agreed to the ultimatum issued the regional African bloc, the African Union and which is supported by United States Secretary of State Hillary Clinton and other western diplomats.
Although discreet, the M23 presence in Goma was still noticeable Friday. Political officers of the movement were going about their business Friday morning, giving no sign of packing up to leave the city.
"We are leaving Goma to give a chance to peace and to make (Congolese President Joseph) Kabila assume his responsibilities," assured Stanislas Baleke, an M23 political cadre.
Although several U.N. reports have clearly indicated Rwanda's role in propping up the rebels, the U.S. and others have so far not publicly called out Rwanda, with U.S. Secretary of State Clinton sidestepping a question on the issue at a press conference this week.
But on Friday the British government announced that it will not release its next payment of budget support to Rwanda. United Kingdom International Development Secretary Justine Greening said that the >21 million ($33.7 million) of general budget support, which was due in December, is not being disbursed as a result of Rwanda's role in the conflict in Congo.
"The government has already set out its concerns over credible and compelling reports of Rwandan involvement with M23 in DRC. This evidence constitutes a breach of (our) partnership principles," he said, "And as a result I have decided not to release the next payment of budget support to Rwanda."