Map of Narracoopa for However, such preparations were difficult due to Japan’s almost complete lack of oil reserves. By the late 1930s, Japan produced only about seven percent of its own petroleum. About 80 percent of its imports came from the United States and another ten percent came from the Dutch East Indies. Therefore, any war against the United States would be extremely harmful to Japan. This situation led the Japanese to implement new restrictive oil policies in order to reduce the role of foreign oil companies in Japan, and to prepare for any potential military conflicts. The official outbreak of war with CHINA in 1937 did lead the government to seek to improve its relationship with the foreign oil firms. The government also devised an ambitious but ultimately unrealistic plan to develop synthetic fuels. Map of Narracoopa 2016.