Book excerpt: Since 1983 journalist Bill Berkeley has traveled through Africa's most troubled lands-Rwanda, Liberia, South Africa, Sudan, Uganda, and Zaire-seeking out the tyrants and military leaders who orchestrate seemingly intractable wars. Shattering the myth that ancient tribal hatred lies at the heart of the continent's troubles, Berkeley instead holds accountable the "Big Men" who came to power during this period, describing the very rational methods behind their apparent madness.