African states are institutionally weak and vulnerable to internal and specifically non-military pressures such as the environment. States in Southern Africa are no exception in this regard. Environmental degradation in Southern Africa has been taking place for decades, if not centuries. As elsewhere on the continent, environmental degradation and the competition for natural resources are prompting massive migrations of people and putting new pressures on state boundaries. These forces interlock with political and economic centrifugal forces on these states. The threats to state institutions are specific and measurable. These are, amongst others, water shortages, deforestation and the relentless advance of the Kalahari desert, soil erosion, the scarcity of agricultural soil, and disease ( Africa Confidential, 6 January 1995: 1-4).