When imperial powers carved up Africa's borders a century ago, they created artificial boundaries that have proved remarkably resilient.
Independence and civil wars have done little to change the map. But now these frontiers may be coming under assault as the nature of conflict changes on the continent from ideological to factional and ethnic confrontations.
The occupation of a large tract of eastern Zaire by Tutsi rebels backed by Rwanda has provoked a debate about whether borders should now be redrawn.
"There is a new crescent of Tutsi control in the Great Lakes" region in Central Africa, says one senior African diplomat. "Ultimately, this could mean a reshaping of Africa."
More than at any time since the end of the cold war, internal rebellions are seeping across borders.
Rwandan soldiers brazenly walk around eastern Zaire. Renegade Zairean militiamen, with alleged support from Sudan, attack positions within Uganda. Eritrea and Ethiopia complain that Sudan's Islamic fundamentalist rulers have sent fighters onto their soil to destabilize their governments.
In turn, Uganda - and reportedly Eritrea and Ethiopia, too - is aiding Sudanese rebels trying to topple the Khartoum regime.
With anarchic Zaire threatening to implode following the loss of most of its North and South Kivu provinces along its eastern border, Africa watchers are pondering the implications. They are divided over whether the trend toward disputes that do not respect the sovereignty of neighboring countries will actually reshape frontiers or simply increase cross-border raids.
"Instead of formally inventing new boundaries, we may see a situation like in the Middle East, where there are occupied territories," says one African diplomat.
The borders drawn up by European colonial powers have long been porous for ordinary Africans. Trade routes that existed centuries ago continue to be used in West Africa. Smugglers routinely ignore the formalities normally required to pass from one country to another.
All over Africa, people simply walk into the next country without passports at points in the bush where there is nothing to distinguish where one country ends and another begins.
But the situation in Central Africa has taken on a lethal dimension because of ethnic clashes. The rivalry between the Hutu and Tutsi ethnic groups involves five countries and the conflict spills across their borders.
The strife, like ethnic conflicts in Nigeria and Angola, is part of the legacy of misguided colonial policies that created borders ignoring tribal lands and favoring one group over another.
The Hutu-Tutsi slaughter over the past three years has claimed more than 1 million lives and sent 2 million into a diaspora in Tanzania, Uganda, and Zaire. At least 800,000 of these refugees have returned home, but the rest are still scattered around the region.
Borders ignore history
"Borders are somewhat irrelevant, with respect to the Central African region and especially the Great Lakes," says Adonis Hoffman, a senior fellow at the Carnegie Endowment for International Peace in Washington.
"Those borders were drawn after World War I, but they failed to take into account the ethnic and regional history and the alliances of the inhabitants crossing the borders. That is why we are now seeing Tutsis and Hutus cross between Rwanda and Burundi and eastern Zaire."
The new conflicts are different from more traditional disputes over frontier areas rich in natural resources. Tradition conflicts include Eritrea and Yemen, who have come to blows over the Hanish Islands in the Red Sea, believed to lie over oil deposits. Cameroon and Nigeria are also at odds over an oil-rich region.
Africa analysts attribute the new type of conflict to an increase in gun smuggling and the end of superpower interest in the region. International disengagement means that disputes become more local and community-based.
In the case of anarchic Zaire, the erosion of centralized power was also a factor. Borders can only be defended if there is effective central control - something severely lacking in Zaire.
A dangerous tit for tat
Once a country feels its sovereignty has been threatened, a dangerous spiral of counter-attacks begins, says George Ayittey, a Ghanaian economics professor at the American University in Washington.
"It is like a tit for tat," he says. "They say: 'If you support the rebels of my regime, then I'll support the rebels of your regime.' "
The 53-member Organization of African Unity (OAU), Africa's main political grouping, is opposed to redrawing any borders. One of the founding principles in its charter drawn up 30 years ago is the "respect for territorial integrity."
Lack of recognition from the OAU may appear to be a disincentive to countries thinking of redrawing borders. But the OAU is an cash-strapped body that has never been effective in defusing conflicts or imposing sanctions on recalcitrant members.
Rwandan officials have called for a review of the decisions made in Berlin in 1884-85 when colonial powers divided up the continent among themselves.
Many analysts, however, say that this is just rhetoric. They maintain that Rwanda's main aim in eastern Zaire is to establish a buffer zone and a proxy to oust the hostile government of Zaire.
And to aid their ethnic brethren. "It was not an assault on Zaire's borders. They went to the support of their brothers in Zaire," Professor Ayittey says.