At a lunchtime reception for the diplomatic corps in Washington, given the day before the inauguration of Barack Obama as president, I was approached by a good-looking man who extended his hand. 'We once met many years ago,' he said. 'And you knew and befriended my father.' My mind emptied, as so often happens on such occasions. I had to inform him that he had the advantage of me. 'My name is Hector Timerman. I am the ambassador of Argen