As shortages of things like electricity, oil and even food grow, so will conflicts of interest.

Ideally, southern Africa should try to produce its own electricity for the whole subcontinent. As supplies of coal and other fossil fuels dwindle, there will be increasing reliance on hydroelectricity from the Zambezi and the Congo -- but countries along those rivers will want to serve themselves first, and sell the surplus to others -- while there is a surplus.

So which rout to go -- cooperation in the subcontinent, or autarky?