Leading article: The unenviable task that faces the next leader in Abidjan

Ivory Coast's capital was the most sophisticated city of the region. How can it have fallen so terribly apart?

Economic prosperity brings stability and peace. That, at any rate, has been for years the premise behind aid to poverty-stricken and war-torn regions in Africa. It is a premise which appears gravely challenged by the recent weeks of chaos in Ivory Coast whose people once had the highest living standards anywhere in the continent but whose lives have now been torn about by bloody civil war.

Ivory Coast was once the economic powerhouse of West Africa. It produced almost half the world's cocoa and for 20 years maintained an annual economic growth rate of nearly 10 per cent, the highest of any African nation without oil. It contributed 40 per cent of the GDP of the West African Economic and Monetary Union and its people had an average annual income of $960 on a continent where many people live still on little more than $1 a day. Only South Africa and oil-rich Nigeria and Angola exported more. Its commercial capital, Abidjan, was the region's most sophisticated and cosmopolitan city. How can it all have fallen so terribly apart?

In fact, it is precisely because that strong economy came under pressure that chaos has ensued. The basis of the country's economic success in the four decades that followed independence was the production of cocoa, coffee and sugar. It also had sensible policies of economic diversification and it encouraged foreign investment, but commodities were what drove the success. The first problem came in the 1980s with a massive local drought which sent the economy into shock. World recession then brought big drops in commodity prices. Debts tripled. More recently it has faced further falls in commodity prices and increased competition, as the global recession tightened.

In the good times the nation welcomed large numbers of foreigners to work its huge plantations. Neighbouring countries, such as Mali and Burkina Faso, were among the world's poorest and yet their peoples had ethnic links with the people in northern Ivory Coast. They were all Muslims. But as times grew harder, the government abandoned its policy of striving to avoid ethnic conflicts and gave way to the temptation to exploit those differences. Politicians divided the nation between north and south, Muslim and Christian, cocoa "immigrants" and "true Ivorians". So pointed did this become that the then president, Laurent Gbagbo, tried to ban his main rival, Alassane Ouattara, from standing for the presidency on the grounds that his parents were originally from Burkina Faso.

The more the economy shrank, and the less there was to fight over, the more bitter the struggle became. When he lost the election last November, Mr Gbagbo refused to step down when Mr Ouattara was declared the clear winner by the West African regional body Ecowas, the African Union, the European Union and the United Nations. The ferocity of the resistance by the southern tribes which supported Mr Gbagbo was a measure of how much they expected to lose if a northerner took power.

Even when the conflict around the presidential residence is over, the problems will be far from solved. An end to the fighting is expected to see the price of cocoa fall further, as the Ivorian supply returns to the world market. At present it is thought to have 400,000 tonnes of cocoa, worth more around $1bn, stored in the country's warehouses.

So the economic prospects for Mr Ouattara look bleak as he gains the presidency. Against that background he has to bring reconciliation to a country divided by a civil war in which both sides have committed atrocities. And he has to find a way of reassuring the 46 per cent of the population who voted against him that he will govern in the interests of the whole nation. It is not an enviable task.