Beginning in 1937 with significant land seizures in China, and to a greater extent after 1941, when annexations and invasions across Southeast Asia and the Pacific created the Greater East Asia Co-Prosperity Sphere, the Japanese government sought to acquire and develop critical natural resources in order to secure economic independence. Among the natural resources that Japan seized and developed were: coal in China, sugarcane in the Philippines, petroleum from the Dutch East Indies and Burma, and tin and bauxite from the Dutch East Indies and Malaya. Japan also purchased the rice production of Thailand, Burma, and Cochinchina.