Kantai Kessen

[1] From the turn of the century up through the start of the Second World War Japanese planners believed achieving victory in such a battle would be dependent upon the effective use of a strong battleship force.

[2] The Japanese triumph at Tsushima led to the naval doctrine of Taikan Kyohō Shugi (大艦巨砲主義), the principle of big ships and gigantic guns.

The Imperial Japanese Navy General Staff was heavily influenced by the writings of the American naval historian Alfred Thayer Mahan.

He asserts that the objective of a strong sea power was to build a fleet capable of destroying the enemy's main force in a single battle.

In that strategic aim Japan faced opposition from Britain and the Netherlands, who held colonial interests in the region, and from the United States, which sought to protect its territories in Guam and the Philippines, and maintain an economic Open Door Policy in China.

Travel to the area of combat would consume the fleet's supplies of fuel and food and would limit the amount of time US Navy assets could operate in the western Pacific.

[8] Japanese naval theoreticians, led by Admiral Satō Tetsutarō, argued that a war against the US Navy fought in a single decisive action could be won by Japan.

[20] Second, Japanese warships needed to possess superior speed and gunnery, capable of hitting at ranges beyond the reach of the US Navy, and had to be manned by very well-trained crews.

[23] Under this plan, Japan would employ submarines, land-based bombers, and light surface forces to whittle down the approaching US fleet to a size that the Japanese could defeat in a fleet-versus-fleet battle.

[27] The most optimistic prewar Japanese policy envisioned a series of sharp blows followed by a successful major sea battle, which would result in a negotiated compromise with Japan's British and American opponents.

[29] The Japanese defensive posture was considerably enhanced after World War I by the South Seas Mandate, in which the League of Nations ceded German possessions in the Pacific to Japan.

Fast heavy cruisers working with destroyer flotillas would attack the US battleships at night, making use of their long-range Type 93 torpedoes to inflict further losses.

[38] Opposition to this doctrine grew in the 1930s, as advocates of the new submarine and naval aviation technologies foresaw that the time for a line of battle between opposing battleship fleets was coming to an end.

[41] Despite being one of the first countries to build aircraft carriers and a naval aviation arm, conservatives among senior commanders did not initially accept its value until the war was well underway, and saw it primarily as a means for reconnaissance and spotting for the battleship force.

The investment Japan made in super battleships meant other types of vessels of the fleet, particularly destroyers and escorts which could be used to protect shipping and screen the carriers, were not built in the numbers needed.

[14] As ship technology advanced the location of the climactic clash moved eastward until, by the late 1930s, the Japanese Naval General Staff planned for it to occur near the Mariana Islands, some 1,400 miles southeast of Japan.

[4] Prewar planning by the USN had focused on the central Pacific and the need for the Navy to gain a series of bases in the Marshall, Caroline, and Mariana Islands.

The offensive into the enemy's territory was to be made in a series of well defined, rapid moves, thereby affording the greatest protection while exposing the US naval forces to the minimum risk and losses.

[46] A major element of Plan Orange was to establish a series of island bases to be used as stepping stones, rather than making a direct strike against Japan.

[50] The aircraft carriers were recognized as the center of the battle plan, as their air groups represented the most lethal striking force with the ability to attack USN units beyond the horizon.

[52] Following the failed campaign at Guadalcanal and the loss of the battlecruisers Hiei and Kirishima, the Japanese withdrew the remainder of their battleship force with intention to conserve them for a hoped for decisive battle.

[55] This conserved the strength of the attacker, while causing the Japanese to effectively lose the services of those units isolated and bypassed, although they still carried the burden of needing to supply them.

[56] These reconstituted carrier air groups were put ashore at Rabaul in November 1943 in an effort to counter US moves into the upper Solomons and Bismarck Archipelago.

[54] The war was tilting ever more in favor of the USN, but with nine carriers and further support from land-based aircraft, the Japanese naval command had reason to believe they had a chance for success.

[60] The Battle of Leyte Gulf several months later was a desperate step to try to use the big guns of the surface fleet to inflict damage upon the USN, but the IJN General Staff held out no hope for gaining a decisive victory.

[62] The performance of individual units of the IJN during the early part of the war was very good and reflected the Japanese idea that quality could make up for lack of quantity.

[68] The impetus behind these plans arose from prewar concerns over the loss of public support among the American people if the fight against Japan dragged on for more than two or three years.

[69] Had the IJN foregone their attacks on Hawaii and the Philippines and concentrated entirely on the conquest of Malaya and the Dutch East Indies, the war might have had a quite different course, given the isolationist mood of the United States in late 1941.

Without realizing it, Japan had entered a war of attrition against a major power whose capacity for industry became focused upon the production of the ships and aircraft necessary to win it.

[81] The production of destroyers and escort vessels, crucial to protection of shipping, were put aside in favor of building large battleships that ended up seeing very limited service.