Kofi Annan, former secretary-general of the UN, is normally the most mild-mannered of men. His peace-making has always been based on patience, persuasion and a capacity to listen calmly to all.

Lately, however, he seems to have been losing his cool. He has just written a blunt personal letter to Silvio Berlusconi, the Italian prime minister, pointing out that Italy is lagging behind all the other rich nations in giving aid to Africa. It is a blatant attempt at naming and shaming.