Kōsaka Masataka and the Repercussions of the Kyoto School on Postwar Japan: The Anti-Anglo-Saxon Origin of the Pro-American Liberal Leviathan

Kōsaka Masataka (1934–96) was a prominent and self-described realist IR theorist in Japan whose thought shared several key tenets with contemporary liberal internationalism. This article argues that a significant strand of IR theory—one that ultimately supported the US-led international order—originated from an anti-Anglo-Saxon vision articulated by four Kyoto school scholars, including Kōsaka’s father, during wartime debates. These thinkers proposed a new world order grounded in the concepts of a “pluralistic world” and moralische Energie . Kōsaka transformed these ideas into a framework of plural civilizations, each driven by its own underlying “energy.” In postwar Japan, he pursued what William James termed “the moral equivalent of war,” envisioning a “pluralistic world” sustained by liberal internationalism and led by the US, which he interpreted as inherently pluralistic. By examining the ambivalent relationship between the Kyoto school and Kōsaka Masataka, this article challenges the simplistic Western–non-Western binary in contemporary IR theory.