The Angolan move was designed to save President Laurent Kabila from the rebel armies that had advanced to within 20 miles of his capital, Kinshasa. But the crisis has firmly placed one-time African allies in opposing military camps. The rebellion against Mr Kabila's 16-month-old regime has so far drawn at least six southern or central African countries into the conflict.
Three countries whose leaders have not broken the mould of the Marxist traditions that formed them - Angola, Zimbabwe and Namibia - find themselves lined up on the side of Mr Kabila against Uganda, which, while it has not embraced multi-party politics, has modernised in a way that finds favour with the west and its ally Rwanda, whose Tutsi-led regime has been trying to snuff out Hutu extremists based in eastern Congo since their genocide of 800,000 Rwandan Tutsis in 1994.
A South African-inspired ceasefire, designed to prevent the three-week- old, rebellion escalating into a regional war was shot down before it got off the ground yesterday as Angola's troops flooded into Congo from its oil rich Cabinda enclave.
South Africa warns that the rebellion in Congo puts Africa on the brink of unprecedented conflict. Yesterday African leaders, like Angolan president Eduardo dos Santos, took one step nearer the abyss, after refusing to join South African president Nelson Mandela for peace talks at the weekend.
The 14-member Southern African Development Community, chaired by Mr Mandela, was formulating a ceasefire proposal - "unanimously" passed despite the absence of Mr dos Santos and Zimbabwean president Robert Mugabe, who has also sent in troops to help Mr Kabila - as Angolans were making their first foray into south-west Congo.
They retook Kitona from the rebels cutting them off from their main western airbase and from where they began their assault on the Congloese capital Kinshasa. They also claim to have snatched other nearby towns from rebel control.
Outside military intervention - which has led to an acrimonious split between Mr Mugabe and Mr Mandela - has given breathing space to Mr Kabila whose days, even until the weekend, were numbered. But what is good news for Mr Kabila is bad news for the region as a whole. SADC was formed first of all as a group for economic co-operation among countries bordering South Africa, and then brought in South Africa once apartheid was overthrown. Now the group that was built to develop the common economic interests of African countries is split down the middle.
Yesterday the Congolese government was jubilant. Angolan and Zimbabwean planes, it said, were attacking the western rebel units from both sides. In rebel-held territory in eastern Congo, rebel spokesman Arthur Ngoma admitted his troops had been forced to make a "strategic pull-back" on the western front.
The horrific reality is that the Rwandan forces backing the rebellion will not just give up and go home. It was Rwanda and Uganda who ironically put Mr Kabila in power more than a year ago when they helped him oust Mobutu Sese Seko, Congo's (then Zaire) long-term dictator.
The deal was that Mr Kabila would secure Uganda's borders from anti-government forces and prevent Hutu extremists, responsible for the genocide of 800,000 Rwandan Tutsis in 1994, from using eastern Congo as a base from which to continue attacks into Rwanda. Mr Kabila not only failed to honour the bargain; he even got cosy with his former sponsors' enemies.
Foreign policy in Rwanda, where the minority Tutsis now govern the Hutu majority, is entirely centred on the security question. Rwanda's second invasion of Congo, like the first, is regarded pure and simple as a battle for ethnic survival. Analysts are now waiting for Uganda - which already has troops in eastern Congo - to send in soldiers to support its ally Rwanda on the western front.
Though Ugandan president Yoweri Museveni attended the SADC peace talks and, like Rwandan president Pasteur Bizimungu and the Congolese delegation sent in place of a "sick" Mr Kabila, gave public backing to a ceasefire call, he also said that Uganda would protect its interests with force if Zimbabwe and Angola did not withdraw their troops.
Congo's rebellion is already affecting events in its many neighbouring countries. Yesterday Angola was the first to feel the backdraft. For months the MPLA government and UNITA rebels have been inching back towards civil war. Yesterday UNITA announced it was cutting ties with peace observers, Portugal, the United States and Russia, effectively abandoning the peace accord between itself and the Angolan government.
The Congolese war has breathed new life into the Angolan rebel force. Just a year ago it, and its leader Jonas Savimbi, were written off when the ousting of Mobutu cut off its arms supply routes.
There are reports that UNITA has found a new role - and new allies - fighting on the side of the Rwandan-backed rebels. More crucial perhaps is the fact that involvement in Congo has weakened the Angolan government's military position at home, and UNITA may have grabbed a chance to take advantage.
The autocratic Mr Mugabe its said is supporting Mr Kabila to stop his own disgruntled population entertaining notions of rebellion. The saddest part is that the free-for-all promises to bring more havoc to countries whose prospects were just beginning to look brighter.
President Mandela had to scramble to convince SADC members to push for a negotiated settlement in Congo. Mr Mugabe's premature military intervention exposed deep divisions within the organisation. The contest between the two men reflects the choices facing Africa.
Mr Mandela preaches the negotiating table and talks. Mr Mugabe still goes for good old-fashioned African brute force.
If, as it looks at the moment, the gun wins, the region is facing a disaster in which many will die and many many more will suffer. And the African Renaissance, punted with such passion by Mr Mandela's successor Thabo Mbeki, will find itself on hold, perhaps indefinitely.Reuse content