Hugo Chavez, Venezuela's radical nationalist president, is among the most vehement Latin American critics of the US. Alvaro Uribe, his Colombian neighbour, is Washington's most important ally in the region. Last weekend they found themselves at loggerheads over a diplomatic dispute that led to the suspension of some commercial ties and withdrawal by Venezuela of its ambassador. With both governments now seeking to mend fences, the two leaders must be helped to limit differences that could eventually provoke a damaging armed conflict.

At the root of the tension is the way a prominent leader of Colombia's left-wing Farc guerrillas - engaged in a 40-year war against the government - was detained last month. Venezuelan national guardsmen picked up Rodrigo Granda, the head of Farc's international relations, in Caracas and handed him over to Bogota. Colombia claims it was in response to the offer of a reward, while Venezuela says the payment was a bribe in an operation that violated its sovereignty.

The incident clearly shows two things. First, Venezuela should be more assiduous in refusing safe haven to Farc guerrillas, whose activities represent a threat to democracy and constitutional rule in Colombia. Second, the Colombian government should not pursue its enemies with tactics that would seem to break international law, even if clandestine operations may have short-term attractions.

Although neither Mr Chavez nor Mr Uribe is likely to go to war over the incident, they need to be encouraged to repair relations. The US has interests at stake, with its support for a multi-billion-dollar drugs eradication and counter-insurgency campaign in Colombia. And after a military coup ousted Mr Chavez nearly three years ago, it was over-hasty in recognising the short-lived government.

But it would not be sensible for Washington to act unilaterally. Instead, the US should support multilateral diplomacy, including the efforts of Brazil's president, Luiz Inacio Lula da Silva, a skilled negotiator who is equally sympathetic to Mr Uribe's efficient style of government and to Mr Chavez's social concerns. Indeed, Mr Lula da Silva - who met Mr Uribe on Wednesday - has sponsored the formation of a South American Community of Nations, whose commitment to open society and regional integration should provide a framework equally acceptable to Colombia and Venezuela.

Both Mr Uribe and Mr Chavez can benefit from stability, closer economic ties and broader regional integration. Mr Lula da Silva and other Latin American leaders need to make sure that the benefits of such co-operation outweigh demagogic or divisive alternatives.

Mr Chavez and Mr Uribe enjoy domestic popularity and seem likely to win further terms in office in elections next year. They are going to be around for some time to come. They need to get used to the fact.