Japan's secret war? ‘Instant’ scientific manpower and Japan's World War II atomic bomb project

Summary This paper questions claims that the Japanese may have succeeded in testing an atomic weapon shortly before the end of World War II. Historical and empirical evidence is examined which suggests that the lack of scientific expertise in nuclear physics hampered the development of an atomic bomb, the most qualified scientists generally being unwilling to become actively involved in the Japanese project. The paper looks at the wartime mobilization of Japanese scientists; outlines the Japanese atomic bomb project; examines claims that Japan succeeded in completing an atomic weapon; and concludes with a look at the ramifications of the historiography.