Rwanda is best known for the 1994 genocide in which Hutu tribesmen killed 800,000 of their Tutsi rivals. Coffee, one of the country's biggest exports, was also a casualty of that massacre. For Michigan State University professor Dan Clay, a specialist in Third World agricultural development, rebuilding Rwanda's coffee industry proved a double-edged challenge: how to get the industry on its feet yet avoid the commodity trap that dooms many farmers to subsistence living in a world where coffee is abundant.
The solution was to go upmarket and try to make Rwanda more famous for fabulous coffee than for murder. Rwanda...