The Foreign Policy Failed States Index shows a strong correlation between environmental sustainability and political stability.
In poorly performing states on the edge, including Bangladesh, Egypt, and Indonesia, the risks of flooding, drought, and deforestation have little chance of being properly managed.
This means displaced peasants, food and water shortages, economic upheaval, with the inevitable political unrest that will follow.
Worse, failed states can and do affect entire regions, destabilizing other countries too.