IN THEORY, the Bolivarian Alternative for the Americas, better known as ALBA, is a Venezuelan-led trade pact based on the principle of “solidarity”. Set up three years ago by Cuba's leader, Fidel Castro, and his close ally, Hugo Chávez of Venezuela, it rejects the free-trade model of integration espoused by the United States. Many have dismissed it as a group of client states, sustained by Venezuelan oil money. Now Mr Chávez wants to turn it into a mutual defence pact that would protect its members from attack by the United States or its ally, Colombia.

“We should work on a joint defence strategy,” Mr Chávez said this week, “because [our] enemy is the same—the United States empire.” This is a thesis that the Venezuelan president has been promoting since 2000 among his South American neighbours, who have in general politely ignored it. The other three members of ALBA are Bolivia, Nicaragua and the tiny Caribbean island-state of Dominica. As they are among the poorest nations in the hemisphere, the idea of a military alliance has been met with some derision, especially now that Nicaragua and Ecuador, another Chávez ally, appear to have ruled themselves out.

Nonetheless, it marks a further escalation in the war of words between Mr Chávez and his Colombian counterpart, Álvaro Uribe. Days before his ALBA comments, Mr Chávez accused America and Colombia of planning a “military provocation” to draw Venezuela into war and thus destroy the seeds of his desired continental socialist revolution. Daniel Ortega, Nicaragua's president and his friend, joined in the sabre-rattling: “To touch Venezuela is to set the region on fire,” he said.

Nicaragua accuses Colombia of failing to respect the maritime limits between the two countries around the disputed Caribbean islands of San Andrés and Providencia. Colombia, which dismisses the claim, has largely ignored the stream of personal insults against its president emanating from Caracas, while marshalling support from the European Union as well as the United States. It is thought that Mr Chávez is merely looking to boost his flagging support at home by manufacturing an external enemy. But with a volatile 2,200km (1,400 mile) common border, infested with irregular armed groups, neither country can be certain his brinkmanship will not lead them over the edge.