The United Nations Secretary General Ban Ki-moon is due to attend a summit in the Kenyan capital, Nairobi, of African leaders to discuss solving the crisis in the Democratic Republic of Congo.
It is the latest effort by the international community to resolve the long-running conflict in DR Congo which has been described, because so many countries were involved at its height, as "Africa's First World War".
Ahead of the summit, the President of Rwanda, Paul Kagame, lambasted DR Congo and the international community for, in his words, failing to deal with what he said was the principal cause of the fighting around the eastern Congolese city of Goma.
Paul Kagame said that the "root cause" was the Hutu militia responsible for the genocide of Tutsis and moderate Hutus in 1994 in Rwanda - and still present in the forests around eastern DR Congo.
President Kagame laid out his tough stance, under questioning from the BBC, as his spokeswoman said he was committed to attending the Nairobi meeting - which now promises to be a tense and frank exchange.
DR Congo, which will also be at the meeting in Nairobi, meanwhile blames Rwanda for many of its problems.
I can assure you if this approach continues, six months down the road we will have another humanitarian catastrophe like this one
Paul Kagame, Rwandan President
On at least two occasions since the genocide in Rwanda in 1994 of Tutsis and moderate Hutus by an extremist Hutu regime, the Rwandan army, one of the toughest in Africa, has directly invaded DR Congo.
Rwanda's target, it says, was - and remains - the remnants of the Hutu extremists who were chased into DR Congo by a Tutsi-dominated military force headed by Paul Kagame.
This history is the key to what is happening in DR Congo today.
The Congolese Tutsi rebels led by Laurent Nkunda who went on the offensive around Goma, causing the current crisis, also say they are defending themselves - and Congolese Tutsis - against the Hutu militia in DR Congo.
At a press conference in the Rwandan capital Kigali, the president told the BBC that the ethnic Hutu militia in DR Congo were still at large.
They now go by the name Forces Democratiques pour la Liberation du Rwanda (FDLR) and are widely believed to be a well-organised group which exploits Congolese resources and attacks civilians.
President Kagame said the current unrest around Goma was fundamentally due to the continued existence of the FDLR.
"How can you deal with this urgent humanitarian problem", he asked, "without addressing that root cause?"
He blamed DR Congo's government under President Joseph Kabila, and the country's UN peacekeeping force, Monuc, for failing to address the problem.
It was the international community, he said, including the UN force, that had failed to act: "what have they been there doing? What solution have they brought to the problem? What is the result of the $1bn they are spending every year?"
And he accused various mediators of disingenuously covering up the problem by attempting to find a solution through direct talks between him and President Kabila:
He maintained that those arguing that talks between Rwanda and DR Congo would resolve the current crisis were simply evading their responsibilities.
"It is running away from the problem", he said. "I can assure you if this approach continues, six months down the road we will have another humanitarian catastrophe like this one."
The Congolese perspective is quite different.
In the DR Congo capital Kinshasa most people hate Rwanda. They say Rwanda - and more particularly President Kagame - has exploited and dominated DR Congo.
The Congolese Tutsi rebels led by Laurent Nkunda say they are defending themselves against the same Hutu militias targeted by Rwanda - the FDLR.
This has prompted many allegations that Rwanda is tacitly supporting Gen Nkunda's army. It's a charge Kigali has always denied.
Israel of Africa
And so tiny Rwanda, bordering giant, chaotic DR Congo, yet again finds itself at the heart of a much bigger problem. Rwanda is the Israel of Africa.
Rwanda's own genocide was in 1994 when some 800,000 Rwandan Tutsis were massacred by an extremist Hutu government.
But after the Tutsis won a military victory they, like the Israelis, felt they had to defend their territory with an iron fist. And they continue to do so.
Rwanda warns that unless the Hutus are disarmed, there will always be a need for the Congolese Tutsis to defend themselves - which, in turn, means more war and more streams of homeless civilian victims.
Rwanda's critics say it uses the presence of the FDLR as a pretext to plunder its vast, mineral-wealthy neighbour. Rwanda denies this, but says that even if that were the case - why not deal with the FDLR, thus removing the pretext?
That challenge by Rwanda could be a bluff - but if so, will the international community call Rwanda's bluff by neutralising the Hutu militia?
On past form, that seems unlikely. And in any case, many diplomats are deeply sceptical about Rwanda's claim that it does not back Gen Nkunda.
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