Although the term "natural disaster" applies to the December 2004 tsunami, the images of huge devastation that were televised after the tragedy probably seemed a good deal less "natural" to us than those of starving African children we saw seven months later, from Niger. The tsunami was perceived as so "un-natural" that it provoked an immediate, unprecedented international outpouring of sympathy. It took many months, by contrast, for the story of a new famine in the Sahel to make headlines. From the outset its causes were apparent in media coverage-droughts and locust invasions have always...