Celso Amorim, Brazil's foreign minister, is visibly tired. But, he admits: "Sometimes frustration is worse than tiredness. And I cannot help but feel very frustrated." Mr Amorim has just returned from Geneva and the collapse of the World Trade Organisation's Doha negotiating round, which ended last week after seven years of exhaustive and at times acrimonious negotiations.
The failure of the talks, Mr Amorim says, will have dire consequences, including the death of more people from starvation and the destabilising of more governments by runaway inflation. Such dangers are more likely to affect poor countries than the rich nations - especially in the US and Europe - whose farm subsidies and import tariffs Mr Amorim and his colleagues from the G20 group of developing nations had hoped the Doha round would dismantle.
So it is especially frustrating for Mr Amorim that the collapse of the talks was caused by India's refusal to give ground on measures to protect its non-farm sectors and by unwillingness by China and even Argentina, Brazil's main partner in the Mercosur customs union, to join Brazil in making similar concessions in the name of a multilateral agreement. "Perhaps some of those leaders, evaluating what it means not having the round, and making some mutual concessions, could still decide that it would be useful and try to finalise the talks. But that is a very Panglossian idea."
Much more likely, he says, is "a real fragmentation of world trade", with more bilateral agreements, more dispute settlement procedures at the WTO and, especially, more protectionism. The Doha talks stumbled several times. A ministerial meeting in Cancún, Mexico, in 2003 brought it close to collapse and Brazil was blamed by the US and others for leading a group of "nay-sayers" in the G20. Since then, however, Mr Amorim and his team have taken the lead in building consensus among developing nations that offered a chance of bringing the talks close to a successful conclusion.
Brazil, for example, came close to an agreement with the European Union that would have given access to the EU's ethanol market in exchange for concessions on Brazilian barriers to manufactured goods that Brazil's private sector seemed willing to accept. "Our proposals were already being seen two or three years ago as marking out the middle ground," Mr Amorim says. "We invented the formula for market access in agriculture, we invented almost everything in the agricultural area. And we were willing to make leaps in the dark."
One immediate consequence of the collapse is that Brazil will take action against the US on subsidies to cotton producers and on import tariffs on Brazilian ethanol. In the medium term, Brazil, as part of the Mercosur customs union, will seek bilateral agreements with the US, EU and others.
But Brazil's ability to lead Mercosur will have been damaged by what many in Argentina saw as its betrayal of its partners in Geneva by its willingness to make concessions on manufactured imports.
Mr Amorim says such disagreements are not as severe as they may seem. But Luiz Inácio Lula da Silva, Brazil's president, who was due to meet President Cristina Fernández of Argentina in Buenos Aires last night, may have a hard time settling their differences.
The longer-term outlook, Mr Amorim says, is bleak. "It's not that world peace is at risk. The world today is different from the 1930s. But many countries will be destabilised."
What can be done? "We will reinitiate negotiations with the EU and we will have to start other talks. [On Friday] I had the trade minister of Indonesia here talking about Asia and Mercosur and how we can progress. "These things all have merits. But in relation to the Doha round they are all second best because they are not dealing with the main distortion to world trade, which is subsidies."