Leading article: President Bush's nuisance neighbours

The victory of Evo Morales in the Bolivian presidential elections is another blow to the Bush administration's ambitions to wield influence in South America. One of Mr Morales' first promises has been to increase the cultivation of coca in order to help small farmers. This is bound to antagonise Washington, which argues that Bolivian coca is the main ingredient of the illicit cocaine that reaches America.

And Bolivia is far from the only South American country prepared to defy the mighty US these days. Mr Morales' government will join a bloc of leftist administrations - which includes Brazil, Chile, Argentina, Uruguay and Venezuela - apparently united in antipathy to the 43rd President of the United States. This new mood was brought home to Mr Bush by the torrid reception he received at last month's Summit of the Americas in Argentina.

It all makes for quite a contrast with the situation five years ago. Immediately after his election in 2000, Mr Bush seemed intent on forging good relations with South America. The Mexican President Vicente Fox was the first foreign leader to visit Washington. And talk of a South American free-trade union was still live. So where did it all go wrong?

In fairness, the breakdown in relations can be partly explained by forces beyond Mr Bush's control. In the 1980s, Latin American governments embraced the so-called Washington consensus, rapidly liberalising their economies. This has resulted in massive inequalities of wealth. Now a growing number of governments are being elected with a mandate to shun the neo-liberal economics pushed by their rich northern neighbour. Any US president would have been faced with increased hostility.

But the Bush administration must also accept a large degree of responsibility. In the wake of the 11 September terrorist attacks, Washington has neglected the region. And when it has become involved, it has been at best clumsy. The invasion of Iraq contributed to the breakdown in trust. Many South American governments were instinctively against the war. The aborted coup in 2002 against the Venezuelan President Hugo Chavez - with suspected CIA involvement - damaged relations further. And now even President Bush's cordial relations with Mexico are under threat, after US proposals to build a fence to keep out migrant Mexican workers.

The situation is not beyond repair. Many governments in the region, such as Brazil, are leftist but moderate. Firebrands like President Chavez are in a minority. And most South American nations are still heavily reliant on trade with the US. The economic incentive for co-operation is strong. Yet unless President Bush pays a good deal more attention to his southern neighbours in coming months, he will find that his list of allies in the region grows shorter still.