Decimation means the killing of every tenth person in a population, and in the spring and early summer of 1994 a program of massacres decimated the Republic of Rwanda. Although the killing was low-tech--performed largely by machete--it was carried out at dazzling speed: of an original population of about seven and a half million, at least eight hundred thousand people were killed in just a hundred days. Rwandans often speak of a million deaths, and they may be right. The dead of Rwanda accumulated at nearly three times the rate of Jewish dead during the Holocaust. It was the most efficient mass killing since the atomic bombings of Hiroshima and Nagasaki.