Since World War II, the Southeast Asian countryside has changed considerably. Sedentary agriculture has expanded to regions never reached before. As a result, forests have retreated to such an extent in some countries, like Thailand or the Philippines, that the forests can no longer supply the internal market. However, this combination of agricultural expansion and deforestation is not specific to Southeast Asia; rather it is a universal process. Other examples, drawn from other regions of the world are examined; they all underline the fundamental role played by the State at each level of the process.