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Japan Ground Self Defence Force
Nihon Rikujyo Jieitai

The largest of the three services, the Ground Self-Defense Force (GSDF), operates under the command of the chief of the ground staff, based in the city of Ichikawa, east of Tokyo.

Strategy is determined by the nation's elongated insular geography, its mountainous terrain, and the nearness of the Asian mainland. The terrain favors local defense against invasion by ground forces, but protection of the approximately 15,800-kilometer coastline of the four main islands would present unique problems in the event of a large-scale invasion. Potentially hostile aircraft and missile bases are so close that timely warning even by radar facilities might be difficult to obtain. Maneuver space is limited to such an extent that ground defenses would have to be virtually in place at the onset of hostilities. No point of the country is more than 150 kilometers from the sea. Moreover, the straits separating Honshu from the other main islands restrict the rapid movement of troops from one island to another, even though all major islands are now connected by bridges and tunnels. Within each island, mountain barriers and narrow roads restrict troop and supply movements. The key strategic region is densely populated and highly industrialized central Honshu, particularly the area from Tokyo to Kobe.

Japan has many places suited for landing operations and is geographically located close to neighboring countries on the continent. It is expected that an aggressor will attempt to assure the safety of its landing forces by concentrating its naval and air assets to secure overwhelming combat power at the time and on the point they choose. It is extremely difficult, or practically impossible, for Japan to have enough defense capability to repel all troops of an aggressor on the sea. It would incur enormous and unbearable costs to build up such defense capability. Consequently, we need to preserve an adequate ground defense capability to destroy those aggressor troops on the ground who have succeeded in their landing operation. A robust ground defense capability to repel an aggressor, which might succeed in breaking through our maritime defense, will enable us to maintain solid defense posture required for effective deterrence against an aggression.

Intended to deter attack, repulse a small invasion, or provide a holding action until reinforced by United States armed forces, the ground element is neither equipped nor staffed to offer more than a show of conventional defense by itself. Antitank artillery, ground-to-sea firepower, and mobility were improved and surface-to- ship missiles were acquired in the Mid-Term Defense Estimate completed in FY 1990. The number of uniformed personnel is insufficient to enable an immediate shift onto emergency footing. Instead, the ratio of officers to enlisted personnel is high, requiring augmentation by reserves or volunteers in times of crisis. In 1992, however, GSDF reserve personnel, numbering 46,000, had received little professional training.

Although allotted 180,000 slots for uniformed personnel, in 1992 the force was maintained at about 86 percent of that level (with approximately 156,000 personnel) because of funding constraints. The GSDF consists of one armored division, twelve infantry divisions, one airborne brigade, two combined brigades, four training brigades, one artillery brigade with two groups, two air defense brigades with three groups, one helicopter brigade with twenty-four squadrons, and two antitank helicopter platoons.

The GSDF is divided into five regional armies, each containing two to four divisions, antiaircraft artillery units, and support units. The largest, the Northern Army, is headquartered on Hokkaido, where population and geographic constraints are less limiting than elsewhere. It has four divisions and artillery, antiaircraft artillery, and engineering brigades. The Northeastern Army and the Eastern Army, headquartered in Sendai and Ichikawa, respectively, each has two divisions. The Central Army, headquartered in Itami, has three divisions in addition to a combined brigade located on Shikoku. The Western Army, with two divisions, is headquartered at Kengun and maintains a combined brigade on Okinawa.

The National Defense Program Outline which determines Japan's defense capabilities, was reviewed and newly established in December 1995. Through a review of the troop structure, the Self-Defense Personnel of the GSDF was reduced from the current 180,000 to 160,000. Some units may be staffed by new Self-Defense Force Reserve Personnel (Ready Reserve Personnel) capable of being quickly mobilized and to create a high-quality and effective system, will be established by 15,000 Ready Reserve Personnel, and 145,000 Regular Personnel. A fundamental review of the troop structure, previously consisting of 13 divisions and 2 combined brigades stationed nationwide, resulted in a balanced deployment of divisions and brigades uniquely suited to the local circumstances of the area where each unit is deployed. Present 4 divisions and 2 combined brigades will be reorganized into new brigades. According to the Outline, the GSDF planned to reduce the four divisions belonging to the Northern Army (two divisions), the Northeastern Army (one division), and the Middle Army (one division) into brigade size and mobilize them, while maintaining the two divisions belonging to the Western Army as they are and turning the First Mixed Group into a brigade.

The previous Outline adopted the concept that Ground Self-Defense Force units to be deployed in peacetime should be deployed in conformity with Japan's geographical characteristics in a well-balanced way so that they can implement systematic defense operations from the outset of aggression in any part of Japan. Specifically, based on the concept that Japanese territory can be divided into 14 districts in light of Japan's geographical characteristics such as mountain ranges, rivers and straits, one division of the Ground Self-Defense Force was deployed in principle in each district while one combined brigade each was deployed in Shikoku and Okinawa. Accordingly, unit structure was of 12 divisions and two combined brigades.

The new Outline sets forth the deployment of eight divisions and six brigades based on the concept that divisions are deployed in districts which are of great importance from the viewpoint of defense and brigades are deployed in districts of relative importance so that divisions and brigades are deployed in an appropriate combination. This setup continues to be the previous Outline's concept that the GSDF units are deployed in conformity with Japan's geographical and other characteristics in order to be capable of implementing rapid and effective systematic defense operations from the outset of aggression, by taking into account the characteristics of each region, such as its proximity to other countries and its political and economic importance, and thereby leaving no room for regional or functional deficiencies.

Specifically, the new Outline sets forth the following deployment:

A brigade is a unit combined with various types of forces, including combat units, such as infantry, armored and artillery units, combat support units and logistical support units. It is a regionally independent and permanent entity. Though its function is similar to a division in that it possesses the capability to engage in operations on one front, it is smaller than a division in scale and has limited capability. (A division in principle consists of 6,000 to 9,000 personnel, whereas a brigade in principle consists of 3,000 to 4,000 personnel.)

To enable regionally deployed units and other units to exercise their defense capability effectively, they should be supplemented, whenever necessary, by the mobile striking capability possessed by tank units, the airborne transport mobility possessed by helicopter units and various airborne operation capabilities. Accordingly, the GSDF, just as it did previously, must possess at least one tactical unit of each of various types of forces used mainly for mobile operation so that it will leave no room for functional deficiencies. Specifically, the GSDF must possess one tank-based armored division, one helicopter brigade equipped with a large type of transport helicopter and one airborne (parachute) brigade.

The ground-to-air missile units of the GSDF engages in air defense operations for units in aggression fronts, as well as for strategical mobile divisions. It also engages in air defense for politically and economically pivotal areas. The GSDF will continue to possess eight anti-aircraft artillery groups as the ground-to-air unit.

From the viewpoint of indicating the basic framework of ground defense capability, the new Outline gives in an annexed table the organized strength of Self-Defense Forces personnel needed to maintain the GSDF defense posture at 160,000. This organized strength is required to maintain major units including divisions, brigades and other main units, as well as supply depots and other logistic support units. Compared with the previous ceiling of 180,000, the new strength has been determined through reorganization of divisions into brigades and other means.

The GSDF units under the new structure are organized in principle by regular Self-Defense Forces personnel in order to maintain a high level of proficiency and to rapidly counter aggressions and other situations. However, from the viewpoint of maintaining personnel in an efficient manner in peacetime and ensuring the flexibility of smooth response to changes in situations, some units will be staffed mainly by high readiness Self-Defense Force Reservists (Ready Reserve Personnel). For example, three of four regiments of a division may be staffed by regular personnel which one regiment may be staffed mainly by Ready Reserve Personnel. Based on such a concept, 145,000 of the 160,000 members of the GSDF will be regular personnel and 15,000 will be Ready Reserve Personnel.

In regard to equipment of the GSDF, the new Outline, from the viewpoint of specifically showing the framework of ground-defense capability, describes in the Annexed Table the number of battle tanks and main artillery (howitzers rockets and SSM launchers), which are main equipment for the GSDF, in addition to the number of main units. Through reorganization of divisions into brigades and other measures, the quota of tanks was set at about 900, compared with 1,200 set in the previous Outline, and that of main artillery at 900, compared with 1,000 in the previous Outline.

In 1989 basic training for lower-secondary and upper-secondary school graduates began in the training brigade and lasted approximately three months. Specialized enlisted and noncommissioned officer (NCO) candidate courses were available in branch schools, and qualified NCOs could enter an eight-to-twelve- week second lieutenant candidate program. Senior NCOs and graduates of an eighty-week NCO pilot course were eligible to enter officer candidate schools, as were graduates of the National Defense Academy at Yokosuka and graduates of four-year universities. Advanced technical, flight, medical, and command staff officer courses were also run by the GSDF. Like the maritime and air forces, the GSDF ran a youth cadet program offering technical training to lower-secondary school graduates below military age in return for a promise of enlistment.

Because of population density on the Japanese islands, only limited areas were available for large-scale training, and, even in these areas, noise restrictions were a problem. The GSDF tried to adapt to these conditions by conducting command post exercises and map maneuvers and by using simulators and other training devices. In live firing during training, propellants were reduced to shorten shell ranges. Such restrictions diminished the value of combat training and troop morale.

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