Japan late in atomic bomb development
Japan also had been secretly conducting research on the feasibility of atomic bombs through two channels. According to a researcher, one channel was the government’s Rikagaku Kenkyusho (Institute of Physical and Chemical Sciences), also known as Riken. The institute’s President Masatoshi Okochi was asked by Takeo Yasuda, chief of the Army’s Air Technical Laboratories, to look into the matter in May 1941. Two years later, Yasuda received a report from quantum physicist and Chief Scientist of Riken Yoshio Nishina that concluded producing atomic bombs was “technically possible.” The other was Kyoto Imperial University Professor Bunsaku Arakatsu, whom the Naval Technical Department asked to “study the possibility of producing atomic bombs.”
However, neither of the research projects ever got off the ground and both ended up only as basic studies.
In July 1944, before the en masse resignation of his Cabinet, Prime Minister Hideki Tojo ordered Seiji Kan, Commander of the Army’s Armament Administration Headquarters, to collect 10 kilograms of uranium as quickly as possible.
Tojo aimed to deter U.S. bombardment of mainland Japan by stunning the United States by dropping a uranium bomb on Saipan. The Imperial Japanese Army attempted to acquire two tons of uranium ore from Germany for the project. However, the submarine carrying the uranium back to Japan was sunk by Allied vessels. The Imperial Japanese Navy also failed to obtain enough uranium to make a bomb. Riken was forced to give up its project after its research facility was destroyed in an air raid in April 1945. The Navy and Kyoto Imperial University were also unable to complete their research before the war ended. “Japan lacked the organization and leadership to mobilize scientists during the war,” Nishina said.