The heads of state/government from this hemisphere assemble in Monterrey, Mexico tomorrow for their summit. They meet at a time when there are strange echoes reverberating across the continent - slightly ironic echoes from Guyana's point of view, although President Jagdeo will not be in Monterrey to pick up the vibes. President Castro, not having been invited, will also be absent, but that does not mean that the spectre of Cuba will not be hovering over the discussions.

There are tensions between the northern continent and the southern one, at the centre of which is Venezuela, perceived by the United States as working with Cuba to foment anti-American sentiment and undermine democratic, pro-American governments in this part of the hemisphere. Unnamed US officials recently were reported by the Associated Press (AP) as saying that the alliance between Cuba and Venezuela combined "Castro's political savvy" with "oil money from Chavez," and that Havana was providing "training, advice and logistical support to leftist groups in the region."

The key allegation from Washington is that Venezuelan funding may have been the decisive factor in the toppling of Bolivia's President Sanchez de Lozada last October. AP also reported the officials as saying that there was evidence of Venezuelan money and manpower being utilized in Ecuador and Uruguay as well to give sustenance to anti-government groups.

Where Bolivia in particular is concerned, AP reported that Venezuela's military attache in La Paz had been expelled for giving money to Mr Evo Morales, the charismatic leader of the coca farmers who were in revolt against the government, and who eventually brought the President down. Three months after Mr Sanchez de Lozada had resigned, Mr Morales visited Caracas along with Pesident Fidel Castro, although he denied having received money from Venezuela's President to finance his popular revolt. The "claim is anonymous and false," he was quoted by Caracas daily El Universal as saying. The paper also reported Venezuelan Vice President Rangel as demanding that the US provide proof that Caracas had helped finance the ouster of Mr Sanchez de Lozada.

Just how strongly Washington feels about the Caracas-Havana axis was revealed by the fact that early last week leading officials went on the record with their concerns. Mr Roger Noriega - whose foreign affairs experience stretches back to a chillier and less democratic era - referred to President Castro as appearing to be "nostalgic for destabilizing elected governments..." Similarly, State Department spokesman, Mr Adam Ereli said, "I would note that the Castro regime... has a long list of attempting to undermine democratic governments throughout the region. And for that reason, the close ties between the government of Venezuela and the government of Cuba raise concerns among Venezuela's democratic neighbours." Finally on Friday, National Security Advisor Condoleezza Rice said that Mr Chavez had played roles which "have not been very helpful."

While Dr Rice had nothing to say on the subject, one of the roles she could conceivably have had in mind is the re-invigoration of the Chile-Bolivia border dispute - Bolivia lost its coastal access to Chile in the 19th century - partly as a consequence of statements made by President Chavez. After a proposal to export natural gas from landlocked Bolivia through Chile had acted as a catalyst in the train of events which brought down Mr Sanchez de Lozada, the Venezuelan President said (and later repeated) that he dreamed of bathing in the Bolivian sea. Subsequently Bolivia received support from former US President Jimmy Carter on the matter, while both UN Secretary General and President 'Lula' of Brazil stepped in to offer their services in the resolution of the controversy. This, it has been reported by Jean Ross in the Independent, has caused President Lagos of Chile to perform something of a volte face, since he had been trying to promote diplomacy on the dispute through multilateral institutions, but is now cornered into insisting that it is a bilateral matter.

In the meantime, according to Ross, Chilean forces are lining up against any cession of territory, although Chile in the past has not been unprepared to cede a corridor to the ocean to her neighbour. We reported yesterday that the Chilean Foreign Minister had told Bolivia not to raise the matter at the summit tomorrow, but Ross said that Bolivian President Mesa had indicated that his country would force the matter of sea access onto the agenda.

Allegations about Venezuelan meddling in the affairs of Bolivia aside, it has to be said that the US administration itself must take a large share of responsibility for what happened in that country. Jeffrey Sachs writing in the Independent described it as an example of the "US poverty of foreign policy," which sees the region solely in terms of counter-narcotics objectives. The underlying issue in the Bolivian crisis was the American coca eradication programme, which had impoverished further thousands of already desperately poor peasants. Sachs wrote that when Mr Sanchez de Lozada warned President Bush last year that extreme poverty and a widening ethnic divide could cause an insurrection, "Bush ushered him from the Oval Office with a pat on the back."

Robert Novak writing in the Chicago Sun-Times, claimed that there was "dismay" behind the scenes in the US intellgience community about what had happened in Bolivia, because aggressive eradication could not now be pursued there, and that this in turn threatened "the unravelling of the US anti-drug program in Colombia." He explained that dissenting officials in the US administration thought that Bolivia was becoming an "ungoverned area," and that Colombia's "narcoterrorists" would move their operations to Bolivia, making irrelevant the American counter-drug programme in Colombia itself.

Where Colombia is concerned, of course, the allegations about links between left-wing guerillas and President Chavez - which the latter has always denied - have been swirling around for a while. As recently as Friday, Dr Condoleezza Rice repeated the claim that Venezuela had allowed its territory to be used as a base for the Colombian guerillas. However, the Miami Herald has said that the Bush administration is divided over the credibility of intelligence reports linking Miraflores directly with the Colombian rebels. The sceptics - among whom the paper said is numbered Caracas-based US Ambassador Charles Shapiro - maintain that Venezuela is in such chaos, that Mr Chavez cannot be blamed for the border situation.

In contrast, according to the daily, what was "widely believed" was that several hundred Cuban security advisers were active in the Venezuelan Directorate of Military Intelligence, as well as DISIP, the country's secret police. The US embassy had broken contacts with DISIP as a consequence last year, which the Herald said had forced the Americans into increasing reliance on Mr Chavez' opponents for information - hardly a source of objective intelligence, one might have thought.

As for the Colombians themselves, the Financial Times on Thursday reported senior officials as expressing the view that President Chavez might be seeking to stir up tensions with their country as an "external distraction" from the possibility of a recall referendum. The paper quoted a Defence Ministry official as saying, "The more difficult the domestic situation gets for Mr Chavez, the more likely he will look to a confrontation with Colombia."