LONDON: There’s an upbeat narrative about Africa — growing middle class, thriving arts and digital culture, “Africa rising” on the cover of the Economist — that’s gaining currency. Such correctives to Afro-pessimism invariably meet their nemesis, however, in eastern Democratic Republic of the Congo.

The deadly militias are back. A mutiny led by war crimes suspect Bosco “The Terminator” Ntaganda has been slicing through the region with apparent ease, terrorising and displacing hundreds of thousands of people. It appears to be the most significantfighting in Congo for five years and has shattered two years of relative peace.

This is a tragedy that stems from ethnic and political wounds dating back to Rwanda's 1994 genocide, which sent a million Hutu refugees fleeing into what was then Zaire.

Later invasions of Congo by Rwandan forces, and Rwanda's backing of Congolese rebels, fuelled two successive wars that sucked in multiple nations, killed several million people and became known as Africa's first world war.

Nearly 18 years later after the genocide, Congo and Rwanda remain locked in a deadly embrace, even though a glance at a mapshows why they have been compared to an elephant and a mouse. Yet tiny Rwanda is the mouse that roared.

In a rare success for the UN, its Group of Experts recently came out with allegations of Rwandan meddling in the current “M23” mutiny against the Congolese government. Research by Human Rights Watch also found the Rwandan military providing hundreds of fighters and weapons across the border. Rwanda vehemently denies the claims.

Why now? Congo's president, Joseph Kabila, was re-elected late last year. With that out of the way, it appears he felt it was time to assert his authority on the east, nearly 1,000 miles from his seat of power, Kinshasa.

In particular, he would seek to rein in the former fighters of General Laurent Nkunda's CNDP (National Congress for the Defence of the People) rebel group, who in theory been incorporated into the Congolese army through a peace deal, but in practice had retained much of their own structure.

Two chains of command were no longer tolerable.

The fact that Ntaganda is wanted by the international criminal court, meaning that his arrest would score points for Kabila among his international backers, may not have done any harm.

But Kabila's push for greater stability has backfired horribly. His army, underpaid and badly treated, appear to lack stomach for the fight and have instead dropped weapons and rolled over, or even defected to rebel ranks.

Town after town has fallen, and now the mutineers almost have the gates of the provincial capital, Goma, within their sights, just as Nkunda did in 2008.

It is hugely embarrassing for the elephant (again). Goma is also the headquarters of the UN peacekeeping mission, the biggest in the world. Could the town fall? Anneke Van Woudenberg, senior researcher for Congo in Human Rights Watch's Africa division, says: “My head says no, but in the past few days the mutineers have taken areas that the UN and Congolese army had considered ‘red lines’ that they would do everything necessary to defend. So we cannot say that Goma is definitely not under threat.”

Such an outcome would surely force Kabila to the negotiating table, but with whom? He would face a Hobson's choice between a group of war crimes suspects with no democratic mandate, or a neighbouring state that denies the first premise of its own complicity.

Diplomatic relations between Kinshasa and Kigali are better than they were, but it is thought that some key Rwandan individuals have a big stake in eastern Congo, not least its lucrative mines.

Meanwhile there seems little prospect of international action against Rwandan president Paul Kagame, a darling of the west. Africa is rising for sure, but not here.

By arrangement with the Guardian