When the African republic of Botswana was born in 1966, its future seemed as bleak as most of its arid countryside. A landlocked nation the size of France, occupied largely by the Kalahari Desert, the former British protectorate was suffering from six years of drought, an impoverished government, and a subsistence economy based almost entirely on cattle raising. Now, discoveries of vast mineral deposits promise to lift Botswana above the problems shared by the rest of black Africa's non-oil-producing countries.
The bust-to-boom turnaround in Botswana began in 1967 with the discovery of the world's second largest diamond "pipe," a gem-rich...