Established after the Meiji Restoration, the Supreme War Council is effectively the inner cabinet of the government of Japan. Originally consisting of the 'Big Six' cabinet positions, the Greater East Asia and Finance Ministries were later attached to the Supreme War Council.

For twenty years the Council was dominated by Prince Konoe, the founder and leader of the Taisei Yokusankai (the Imperial Rule Association, Japan's ruling party), and architect of the joint Axis war on the Soviet Union. He stacked his cabinets with supporters of a crusade against Bolshevik Russia, ousting the influential General Tojo and his anti-American 'Strike South' faction. This proved especially important after relations between Japan and the European Axis Powers (Germany and Italy) began to sour in the late 1940s, while relations between Japan and the United States of America warmed slightly. Konoe also worked toward transforming the Greater East Asia Co-Prosperity Sphere into more than a propaganda tool.