JAPANESE PREPARATIONS FOR THE DEFENSE OF THE HOMELAND
Imperial General Headquarters in Tokyo began planning for homeland defense in early 1944 following American air attacks against the eastern Carolines and Truk. In May Tokyo mobilized the General Defense Command and its subordinate district armies, Eastern, Western and Central. Beginning in July each district headquarters worked on improving coastal defenses and fortifications. Top priority went to building air bases, although fortifications in key areas and road improvements did receive some attention. Construction proceeded sporadically until 1945 when Tokyo accelerated plans for homeland defense. I will discuss the resulting Japanese preparations for the defense of the home islands in terms of manpower, resources, and doctrine.
Japanese manpower was already stretched thinly across Asian and Pacific battlegrounds, and 1944 left a quarter of a million Japanese dead in places such as New Guinea (50,000), Leyte (75,000), Burma (60,000), and the Marianas (64,000). By January 1945 Japan had only eight dito defend the entire homeland (excluding Hokkaido). 1 Reinforcements could come from two sources: established divisions stationed in Manchuria or newly mobilized ones.
On 11 January 1945 Army Chief of Staff General Umezu Yoshijirō ordered all directorates in the war ministry to establish their immediate priorities for homeland defense. Nine days later the emperor approved, and the army promulgated, the overall concept for the defense of Japan.