Luiz Inácio Lula da Silva, Brazil’s president, rarely misses an opportunity to advertise the power of his country’s ethanol industry in his bid to wield greater influence in the world.

But recently a number of leaders in the Americas have begun to share his enthusiasm, arguing that co-operation between the energy-hungry north and the resource- and technology-rich south could form the basis for greater integration and healthier political relations across the hemisphere.