During World War II aircraft production in Japan increased sharply. This column, part of the Vox debate on the economics of WWII, examines the reasons for this ‘production miracle’, focusing on an aircraft manufacturing plant of Mitsubishi Heavy Industries Co., one of the two largest aircraft producers in Japan. The key to the production increase was the expansion of the supplier network. Mitsubishi Heavy Industries organized many suppliers to provide aircraft parts to its plants. However, in the final stage of the war, destruction of the supplier network by strategic bombing and an earthquake caused the collapse of the company’s aircraft production.