It was billed as a clash of the titans. On one side were Hugo Chávez, the fiery Venezuelan president, and his protégé Evo Morales, the Bolivian leader, who a few days earlier had announced the nationalisation of his country's gas sector. On the other side were Luiz Inácio Lula da Silva and Néstor Kirchner, the more moderate left-leaning presidents of Brazil and Argentina, the countries most affected by Bolivia's move.

But the expected confrontation at a summit on the issue last month ended in a round of back-slapping and an endorsement of Mr Morales's move.