Burundi is a land of luxuriant beauty and berserk violence, torn apart by one of those tribal conflicts that are so elusive to an outsider's understanding. Determined to uphold a centuries-old feudal hegemony over 3,000,000 Hutu tribesmen, the well-armed Tutsi overlords, who number no more than 600,000, unleashed a violent pogrom last year. At least 80,000and perhaps as many as 250,000Hutus were killed. In May this year the slaughter revived in the southeastern part of the landlocked hill country (area: 10,747 sq. mi., smaller than Belgium). The latest Tutsi massacre was in...