Serbian efforts to force Bosnian Muslims from cities and villages throughout the Balkans have only recently lodged ethnic cleansing in the public mind. But in the annals of history such atrocities are far from new. From ancient Assyria to modern Serbia, campaigns to homogenize populations within inviolate borders have been carried out variously in the name of God, nation or ideology. Yet ethnic cleansing remains difficult to define. Less understood is the compulsion for national "purity" at such horrific costs. The most likely outcome of the Balkans war is a patchwork of ethnically distinct regions, with few minority populations. Perhaps then the violence will end.