Jeremy Yellen, "The Greater East Asia Co-Prosperity Sphere: When Total Empire Met Total War" (Cornell UP, 2019)

The Greater East Asia Co-Prosperity Sphere functioned as a grand strategy of opportunism rather than a static, coherent blueprint. Initially a vague concept, the Sphere evolved as Japan navigated the geopolitical pressures of World War II, including a defensive alliance with Germany born from mutual distrust. Nationalist elites in the Philippines and Burma practiced "patriotic collaboration," leveraging the Japanese occupation to build essential state institutions like central banks and foreign ministries in preparation for post-war sovereignty. By 1943, Japan increasingly adopted liberal internationalist rhetoric—modeled after the Atlantic Charter—to justify its regional order. While this move aimed to secure imperial survival, it simultaneously provided local leaders with a framework to contest Japanese interference. Ultimately, these wartime institutional developments left lasting legacies, influencing post-war state-building and the region's transition away from colonial rule.