As they advance this week on the southern, mineral-rich provinces of Kasai and Shaba, threatening the diamond mines of Mbuji-Mayi which have served as Mr Mobutu's personal bank for three corrupt decades, the rebels appear to be changing forever the face of Africa's third largest country.
They enter peace talks in South Africa this weekend in a strong position; not bad for a force rubbished by Western diplomats as recently as February.
But the repercussions of the rebellion are being felt beyond Zaire's borders across a vast tract of Africa. It has affected the course of the civil war devastating Sudan to the north and nudged the Angolan peace process back on track tens of thousands of miles to the south by closing the supply routes through Zaire crucial to Unita rebels.
Whether a bigger game plan was envisaged in October when the Rwandan- backed Banyamulenge Tutsis began their revolt in eastern Zaire is a matter of debate. But the question has spawned a multitude of conspiracy theories implicating foreign powers, including the United States.
The most extreme conspiracies claim the US has a masterplan for the region. This view is most popular with the French, utterly wretched about their waning influence in Africa.
But African political analysts also give it credence. The existence of an overall US game plan is not an outlandish proposition, says Richard Cornwall of the Africa Institute of South Africa. He believes an American political "wish list" and US commercial interests have shaped events.
Although the world's attention has been fixed on Zaire and its border with Rwanda, Mr Cornwall places Sudan at the centre of a complex political web. The US's desire to see the overthrow of Sudan's Islamic government - which it accuses of sponsoring international terrorism - led it to provide $20m of non-lethal military aid to neighbouring Eritrea, Ethiopia and Uganda earlier this year.
Until the October uprising, the Ugandan Lord's Resistance Army, backed and sheltered by Sudan, was using north-eastern Zaire to launch raids into Uganda. The Banyamulenge rebellion conveniently allowed Uganda to shut down the LRA's attack route while its ally Rwanda eradicated the Hutu threat which had sat just on its border since the genocide of 800,000 Tutsis in 1994.
Mr Cornwall believes the US gave the nod to Ugandan President Yoweri Museveni and the Rwandans to back the Banyamulenge. Then Laurent Kabila, the rebel leader, was dismissed as frontman and few, if any, recognised the potential for a genuine Zairean rebellion or foresaw just how easily Zaire might fall.
Mr Cornwall places Mr Museveni at the centre of events. The Ugandan president is the role model for an emerging block of African countries - Eritrea, Ethiopia and Rwanda - all headed by second generation, post- independence leaders who have won power through the barrel of a gun, but whose leadership is characterised by good governance.
Eritreans, Ethiopians and Ugandans have all been reported fighting alongside Kabila.
Mr Museveni is a US favourite. But its support for Uganda and Rwanda has brought it into direct conflict with the French which have seen their influence plummet with the change in government in Rwanda and the demise of Mr Mobutu in Zaire.
When France recently tried to step in to save Mobutu's skin the US blocked it.
Of all the old European colonial powers the French alone stubbornly cling to the notion of empire in Africa and believe their influence there is inextricably linked with international standing.
Beyond vain strutting on the world stage Mr Cornwall believes French conflict with the US rests on competition for Africa's vast untapped reserves of minerals and oil. Zaire is rich in cobalt, copper and diamonds and substantial oil finds have been made recently in Angola and Sudan. "The French and Americans are battling it out over hydrocarbons," says Mr Cornwall, who sees parallels with the 19th-century Scramble for Africa during which European governments carved up the continent.
"The French are furious at the US. Their influence is collapsing like a house of cards. And who is responsible? These Yankie Johnny-Come-Latelys who never had an interest before," he says.
The animosity between the French and the US is obvious. Their diplomats in the region have fallen out publicly and quite spectacularly. But Professor Jack Spence, of the Royal Institute for International Affairs, in London, believes this owes more to French paranoia than US commercial or political competitiveness. "Africa really comes quite far down the US's list of priorities," he says. "I doubt President Clinton gives it much thought."
Crawford Young, an authority on Zaire based at the University of Wisconsin, similarly dismisses claims about a US masterplan. "How many times did Warren Christopher visit Africa?" he asks.
US policy in the area, he argues, is an example of preventative politics, driven by the fear that Zaire will fragment and its instability spill over into neighbouring countries. "The US interest is a negative interest. It is a keenness to avoid a humanitarian disaster that would call for an expensive international operation."
Many remain unconvinced. Just how much commercial interests are shaping events now may become clearer with time. What is certain now, however, is that a reborn Zaire, cleansed of corruption, could become the economic powerhouse for the entire region.
It has the potential to provide hydro-electric power for the whole of southern Africa. Mining experts say it is hard to exaggerate the wealth of its mineral reserves. Whether they have interfered or not, it is difficult to imagine that its commercial potential is going unnoticed by western and African governments.