Japan’s Imperial Ideology & Early Atrocities

Japan entered the 1930s under military‑dominated government, driven by the ideology of kokutai (national polity) and the goal of creating a “Greater East Asia Co‑Prosperity Sphere.”¹⁸ This expansionist vision justified conquest, resource extraction, and the subjugation of other Asian peoples.

Japanese army entering Nanking (Nanjing) in December 1937

Unit 731 complex in Harbin, China (site of biological warfare experiments)

In 1937, Japan invaded China, capturing the capital Nanking. Over six weeks, Imperial Japanese forces committed mass murder and rape of an estimated 200,000 to 300,000 civilians and disarmed soldiers – the Nanking Massacre.¹⁹ Beyond Nanking, Japan established a secret biological warfare unit, Unit 731, where thousands of prisoners were subjected to vivisection, plague injections, and frostbite experiments.²⁰

This early pattern of brutality – mass killing, systematic rape, and human experimentation – laid the groundwork for later atrocities, including the Comfort Women system.²¹ Japanese militarism treated conquered peoples as subhuman, and the military leadership actively encouraged violence to break Chinese resistance and maintain troop discipline.

The international community condemned these acts, but the League of Nations failed to intervene. The Nanking Massacre and Unit 731 remained largely hidden from Western textbooks for decades.²²