Think of it as the old Africa and the new. In Mali, a military coup last week toppled an elected civilian government and soldiers went on a rampage of looting. Meanwhile a couple of hundred miles to the south, Ghana has launched a nationwide, biometric process to register every voter by fingerprints ahead of the December elections.

Ghana is an increasingly prosperous and stable democracy with a lively free press. Its economy is growing at close to 10 percent a year and it comes 63rd in the World Bank's ranking of countries on Ease of Doing Business, just behind Poland and just ahead of the Czech Republic. And last year, after a series of dramatic offshore oil finds the World Bank raised Ghana's ranking from a low-income to a middle-income country.

Ghana is a country that is doing almost everything right for its development. The mortality rate for children below the age of 5 has almost halved in the past 20 years and 99 percent of infants are vaccinated against tuberculosis. Only 3 percent of its under-5s are rated as severely underweight by the World Health Organization and 76 percent of its children go through primary school.

By contrast, Mali falls behind on each of these measures of health, education and prosperity. Unlike Ghana, which has a thriving cocoa and gold-mining industry, landlocked Mali has few natural resources and has been facing an armed insurgency from the nomadic Tuareg tribesmen of the vast Saharan desert in the north of the country.

Mali's military coup was triggered by accusations of a feeble government response to this insurgency by army Capt. Amadou Haya Sanogo, the coup leader who had received military training in the United States. But observers in the region claim that the coup followed a series of military setbacks for the army as the Tuaregs were reinforced by fellow tribesman joining their ranks after getting weapons, training and experience while fighting in Libya's civil war.

As so often in the Sahel region -- the borderlands between the Sahara and the more fertile regions that lead down to the West Africa coast -- the trouble has come through ethnic and religious differences between the nomadic Tuaregs of the desert and the settled farmers of the south.

Demanding independence for the northern half of the country, which they call Azawad, some of the Tuareg units have called the adoption of Shariah Islamic law throughout the country. Others have been linked, with little firm evidence, to al-Qaida. The U.S. Air Force was helping the Malian government by air-dropping supplies to beleaguered Malian troops, who have depended heavily on helicopter gunships flown by Ukrainian mercenaries.

The outcome of the coup, denounced by Mali's neighbors who seek to outlaw such coups against elected governments, remains uncertain. The U.N. Security Council called for the "immediate restoration of constitutional rule and the democratically elected government," The African Union issued a statement that "strongly condemns this act of rebellion, which seriously undermines constitutional legality and constitutes a significant setback for Mali. This rebellion has no justification whatsoever, more so given the existence, in Mali, of democratic institutions which provide a framework for free expression and for addressing any legitimate claims."

Meanwhile in Ghana, the election campaign is getting under way between the incumbent National Democratic Congress, led by President John Atta Mills, and the New Patriotic Party, which has a small lead in the polls, led by the fiery Nana Akufo-Addo. Both men are prosperous lawyers.

Broadly speaking, the NDC is center-left, believing in a strong role for the state in directing the economy and managing the exploitation of Ghana's new oil wealth, while the NPP is center-right, preferring the free market. But the NPP's last time in office ended with an exploding budget deficit that peaked at a quarter of the country's gross domestic product in 2008.

The NDC's economic stewardship has been controversial, particularly with a dubious $3 billion loan from the China Development Bank in return for oil from the Ghana National Petroleum Corp., whose revenues were supposed to be servicing an all-time high national debt of more than $18 billion. Both the national Parliament and the International Monetary Fund warned against the deal.

There are also regional and ethnic issues, with the NDC's main power base being in Volta region, dominated by the Ewe tribes, and the NPP strength predominant in the Ashanti region. Both tribal groups are mainly Christian, while the Dagomba of the north are Islamic, but despite recurrent disputes over land, grazing and water, Ghana has largely been spared ethnic and religious conflict.

The main issues seem be focused on the economy, corruption and how long before the oil wealth trickles down to the public. The state electricity company is a source of scandal, failing to collect debts of more than $200 million, much of it owed by some multinational companies and by the president's office.

But in African terms, Ghana counts as a success story, one of the stars of the economic revival which has seen sub-Saharan Africa growing steadily over the past decade. The contrast with the current woes of Mali emphasizes Ghana's achievements and Africa's potential. Mali's coup looks back to Africa's unhappy past.