The strategy for Ketsu-Go was outlined in an 8 April 1945 Army Directive.(4) It stated that the Imperial Army would endeavor to crush the Americans while the invasion force was still at sea. They planned to deliver a decisive blow against the American naval force by initially destroying as many carriers as possible, utilizing the special attack forces of the Air Force and Navy. When the amphibious force approached within range of the homeland airbases, the entire air combat strength would be employed in continual night and day assaults against these ships. In conducting the air operations, the emphasis would be on the disruption of the American landing plans. The principal targets were to be the troop and equipment transports. Those American forces which succeeded in landing would be swiftly attacked by the Imperial Army in order to seek the decisive victory. The principal objective of the land operation was the destruction of the American landing force on the beach.
Ketsu-Go operation was designed as an all-out joint defense effort to be conducted by the entire strengths of the Army, Navy and Air Force. In the various orders and directives issued by IGHQ regarding Ketsu-Go, inter-service cooperation was stressed.(5) The basic plan for the operation called for the Navy to defend the coasts by attacking the invasion fleets with its combined surface, submarine, and air forces. The Air General Army would cooperate closely with the Navy in locating the American transports and destroying them at sea. Should the invasion force succeed in making a landing, the Area Army concerned would assume command of all naval ground forces in its area and would exercise operational control of air forces in support of ground operations. An integral part of the Ketsu-Go operational planning included reinforcement of sectors under attack by units transferred from other districts. Since U.S. air raids had already seriously disrupted the transportation system, time schedules were planned to provide for all troop movements to be made by foot.(6) If the battle at the beach showed no prospect of a successful ending, then the battle would inevitably shift to inland warfare; hence, interior resistance would be planned. Guard units and Civilian Defense Corps personnel, with elements of field forces acting as a nucleus, would be employed as interior resistance troops. Their mission would be to attrite the Americans through guerrilla warfare, espionage, deception, disturbance of supply areas, and blockading of supplies when enemy landing forces advanced inland. It is interesting to note that the Japanese normally exercised little inter-service coordination throughout the war. Now when the homeland was threatened, the Japanese finally stressed inter-service coordination and unity of command.
