The was a naval strategy

Naval strategy

Naval strategy is the planning and conduct of war at sea, the naval equivalent of military strategy on land.Naval strategy, and the related concept of maritime strategy, concerns the overall strategy for achieving victory at sea, including the planning and conduct of campaigns, the movement and...

 adopted by the Imperial Japanese Navy

Imperial Japanese Navy

The Imperial Japanese Navy was the navy of the Empire of Japan from 1869 until 1947, when it was dissolved following Japan's constitutional renunciation of the use of force as a means of settling international disputes...

 following the Russo-Japanese War

Russo-Japanese War

The Russo-Japanese War was "the first great war of the 20th century." It grew out of rival imperial ambitions of the Russian Empire and Japanese Empire over Manchuria and Korea...

. It called on the use of a strong battleship

Battleship

A battleship is a large armored warship with a main battery consisting of heavy caliber guns. Battleships were larger, better armed and armored than cruisers and destroyers. As the largest armed ships in a fleet, battleships were used to attain command of the sea and represented the apex of a...

 force, which would destroy an invading fleet as it approached Japan after suffering losses through attrition as it penetrated Japanese perimeter defenses.

The decisive victory of the Japanese fleet over the Imperial Russian Navy

Imperial Russian Navy

The Imperial Russian Navy refers to the Tsarist fleets prior to the February Revolution.-First Romanovs:Under Tsar Mikhail Feodorovich, construction of the first three-masted ship, actually built within Russia, was completed in 1636. It was built in Balakhna by Danish shipbuilders from Holstein...

 at the Battle of Tsushima

Battle of Tsushima

The Battle of Tsushima , commonly known as the “Sea of Japan Naval Battle” in Japan and the “Battle of Tsushima Strait”, was the major naval battle fought between Russia and Japan during the Russo-Japanese War...

 in the Russo-Japanese War had validated the doctrine in the eyes of the Imperial Japanese Navy General Staff

Imperial Japanese Navy General Staff

The was the highest organ within the Imperial Japanese Navy. In charge of planning and operations, it was headed by an Admiral headquartered in Tokyo.-History:...

, and future naval procurement and deployment was centered around refinements of the “decisive victory”, or kantai kessen doctrine.

Opposition to this doctrine grew in the 1930s, as advocates of the new submarine

Submarine warfare

Naval warfare is divided into three operational areas: surface warfare, air warfare and underwater warfare. The latter may be subdivided into submarine warfare and anti-submarine warfare as well as mine warfare and mine countermeasures...

 and naval aviation

Naval aviation

Naval aviation is the application of manned military air power by navies, including ships that embark fixed-wing aircraft or helicopters. In contrast, maritime aviation is the operation of aircraft in a maritime role under the command of non-naval forces such as the former RAF Coastal Command or a...

 technologies foresaw that the concept of the line of battle

Line of battle

In naval warfare, the line of battle is a tactic in which the ships of the fleet form a line end to end. A primitive form had been used by the Portuguese under Vasco Da Gama in 1502 near Malabar against a Muslim fleet.,Maarten Tromp used it in the Action of 18 September 1639 while its first use in...

 between opposing battleships fleets had been rendered obsolete (Evans 1997). However, conservative supporters of kantai kessen, such as Admiral Osami Nagano, dominated within the senior staff of the Japanese Navy and the kantai kessen concept remained the primary Japanese naval strategy into the Pacific War

Pacific War

The Pacific War, also sometimes called the Asia-Pacific War refers broadly to the parts of World War II that took place in the Pacific Ocean, its islands, and in East Asia, then called the Far East...

.

Background

The senior officer class of the Imperial Japanese Navy was heavily influenced by the works of Alfred Thayer Mahan

Alfred Thayer Mahan

Alfred Thayer Mahan was a United States Navy flag officer, geostrategist, and historian, who has been called "the most important American strategist of the nineteenth century." His concept of "sea power" was based on the idea that countries with greater naval power will have greater worldwide...

, whose works (including The Influence of Seapower Upon History,1660-1783

The Influence of Sea Power upon History

The Influence of Sea Power Upon History: 1660-1783 is a history of naval warfare written in 1890 by Alfred Thayer Mahan. It details the role of sea power throughout history and discusses the various factors needed to support and achieve sea power, with emphasis on having the largest and most...

, published in 1890) were required reading at the Imperial Japanese Naval Academy

Imperial Japanese Naval Academy

The was a school established to train officers for the Imperial Japanese Navy. It originally located in Nagasaki, moved to Yokohama in 1866, and was relocated to Tsukiji, Tokyo in 1869. It moved to Etajima, Hiroshima in 1888...

 and Naval Staff College

Naval War College (Japan)

The was the staff college of the Imperial Japanese Navy, responsible for training officers for command positions either on warships, or in staff roles....

.

Mahan believed that control of seaborne commerce

Commerce

While business refers to the value-creating activities of an organization for profit, commerce means the whole system of an economy that constitutes an environment for business. The system includes legal, economic, political, social, cultural, and technological systems that are in operation in any...

 was critical to domination in war. If one combatant could manage to deny

Sea denial

Sea denial is a military term describing attempts to deny an enemy's ability to use the sea but at the same time making no attempt to control the sea itself. It is a far easier strategy to carry out than sea control because it requires the mere existence of a navy...

 the use of the sea to the other, the others' economy would inevitably collapse, leading to victory. Mahan's theory relied on the use of a fleet of battleship

Battleship

A battleship is a large armored warship with a main battery consisting of heavy caliber guns. Battleships were larger, better armed and armored than cruisers and destroyers. As the largest armed ships in a fleet, battleships were used to attain command of the sea and represented the apex of a...

s to establish command of the sea

Command of the sea

A naval force has command of the sea when it is so strong that its rivals cannot attack it directly. Also called sea control, this dominance may apply to its surrounding waters or may extend far into the oceans, meaning the country has a blue-water navy...

. The Mahanian objective was to build a fleet capable of destroying the enemy's main force in a single decisive battle. After this victory was won, it would be easy to enforce a blockade

Blockade

A blockade is an effort to cut off food, supplies, war material or communications from a particular area by force, either in part or totally. A blockade should not be confused with an embargo or sanctions, which are legal barriers to trade, and is distinct from a siege in that a blockade is usually...

 against the enemy. For the weaker combatant, the goal was to delay such a climactic battle for as long as possible. While their fleet still posed any threat, the enemy could not risk splitting their forces to close off trade routes. This led to the strategy of a fleet in being

Fleet in being

In naval warfare, a fleet in being is a naval force that extends a controlling influence without ever leaving port. Were the fleet to leave port and face the enemy, it might lose in battle and no longer influence the enemy's actions, but while it remains safely in port the enemy is forced to...

, a naval force kept deliberately in port to threaten rather than act. Mahan's doctrines were adopted by a number of navies, notably the Royal Navy

Royal Navy

The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...

 and contributed to types of capital ship

Capital ship

The capital ships of a navy are its most important warships; they generally possess the heaviest firepower and armor and are traditionally much larger than other naval vessels...

s produced in the final years of the 19th and early years of the 20th century.

In the 1907 Imperial National Defense Policy, the shift of Japan's military focus shifted away from the defeated Imperial Russia and towards the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 as the primary threat to Japan's future security. In Japanese minds, the United States had proven to be an aggressive expansionist power in Asia, with its overthrow and annexation of the Kingdom of Hawaii

Kingdom of Hawaii

The Kingdom of Hawaii was established during the years 1795 to 1810 with the subjugation of the smaller independent chiefdoms of Oahu, Maui, Molokai, Lānai, Kauai and Niihau by the chiefdom of Hawaii into one unified government...

 and suppression and colonization of the Republic of the Philippines. The Open Door Policy

Open Door Policy

The Open Door Policy is a concept in foreign affairs, which usually refers to the policy in 1899 allowing multiple Imperial powers access to China, with none of them in control of that country. As a theory, the Open Door Policy originates with British commercial practice, as was reflected in...

 towards China

China

Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...

 was in conflict with Japanese aspirations on the Asian mainland, and its racist immigration policies indicated potential American racial enmity towards the Japanese. Furthermore, the United States Navy

United States Navy

The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...

 had recently surpassed the United Kingdom

United Kingdom

The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

's Royal Navy as the largest and most powerful fleet in the world.

Based on a theoretical United States Navy strength of 25 battleships and heavy cruiser

Heavy cruiser

The heavy cruiser was a type of cruiser, a naval warship designed for long range, high speed and an armament of naval guns roughly 203mm calibre . The heavy cruiser can be seen as a lineage of ship design from 1915 until 1945, although the term 'heavy cruiser' only came into formal use in 1930...

s, Japanese naval theoreticians led by Admiral Satō Tetsutarō

Sato Tetsutaro

-Notes:...

 postulated that Japan would need a fleet of at least eight first-line battleships and eight cruisers for parity. When Naval Minister

Ministry of the Navy of Japan

The was a cabinet-level ministry in the Empire of Japan charged with the administrative affairs of the Imperial Japanese Navy . It existed from 1872 to 1945.-History:...

 Admiral Yamamoto Gonnohyoe

Yamamoto Gonnohyoe

, also called Gonnohyōe, was an admiral in the Imperial Japanese Navy and the 16th and 22nd Prime Minister of Japan.-Early life:...

 presented the budget request for this Eight-eight fleet

Eight-eight fleet

The was a Japanese naval strategy formulated for the development of the Imperial Japanese Navy in the first quarter of the 20th century, which laid down that the Japanese navy should include eight first-class battleships and eight armoured cruisers or battlecruisers.-History and development:The...

 to the Diet of Japan

Diet of Japan

The is Japan's bicameral legislature. It is composed of a lower house, called the House of Representatives, and an upper house, called the House of Councillors. Both houses of the Diet are directly elected under a parallel voting system. In addition to passing laws, the Diet is formally...

, the amount was more than twice that of the entire Japanese national budget at the time. Budget limitations meant that a large percentage of naval procurement was allotted to battleships to complete the Eight-eight Fleet project, at the expense of other types of warships and new technologies.

Battle Plan

The kantai kessen strategy presumed a defensive posture by the Japanese Navy, with the bulk of its battleship fleet in strategic reserve

Strategic reserve

For the military term see: Military reserveA strategic reserve is a term used to describe a reserve of a commodity or items, held back from normal use by governments, organisations or business in pursuance of a particular strategy or to cope with unexpected events.A strategic reserve can be:*...

, as secondary forces based on cruisers and destroyers waged a campaign of attrition

War of Attrition

The international community and both countries attempted to find a diplomatic solution to the conflict. The Jarring Mission of the United Nations was supposed to ensure that the terms of UN Security Council Resolution 242 would be observed, but by late 1970 it was clear that this mission had been...

 against the American offensives . As with the Russian Baltic Fleet

Baltic Fleet

The Twice Red Banner Baltic Fleet - is the Russian Navy's presence in the Baltic Sea. In previous historical periods, it has been part of the navy of Imperial Russia and later the Soviet Union. The Fleet gained the 'Twice Red Banner' appellation during the Soviet period, indicating two awards of...

 in the Russo-Japanese War, the American fleet would need to be drawn out to a long distance away from its source of supplies, and destroyed in a climactic final battle similar to the Battle of Tsushima .

Up until the 1920s the Japanese expected this decisive battle to occur near the Ryukyu Islands

Ryukyu Islands

The , also known as the , is a chain of islands in the western Pacific, on the eastern limit of the East China Sea and to the southwest of the island of Kyushu in Japan. From about 1829 until the mid 20th century, they were alternately called Luchu, Loochoo, or Lewchew, akin to the Mandarin...

 and for the battle to be “a defense of Japan's home waters conducted purely by surface forces.” However, as technology increased the ranges of submarines and aircraft, the projected location of the battle moved further and further eastward. By 1940, the Japanese were planning for the decisive battle to be fought “somewhere east of a line between the Bonin and Mariana Islands

Mariana Islands

The Mariana Islands are an arc-shaped archipelago made up by the summits of 15 volcanic mountains in the north-western Pacific Ocean between the 12th and 21st parallels north and along the 145th meridian east...

.” .

The Japanese defensive posture was considerably enhanced by the acquisition of the South Pacific Mandate

South Pacific Mandate

The was the Japanese League of Nations mandate consisting of several groups of islands in the Pacific Ocean which came under the administration of Japan after the defeat of the German Empire in World War I.-Early history:Under the terms of the Anglo-Japanese Alliance, after the start of World...

 from the League of Nations

League of Nations

The League of Nations was an intergovernmental organization founded as a result of the Paris Peace Conference that ended the First World War. It was the first permanent international organization whose principal mission was to maintain world peace...

 after World War I

World War I

World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

. The Pacific islands (the Caroline islands

Caroline Islands

The Caroline Islands are a widely scattered archipelago of tiny islands in the western Pacific Ocean, to the north of New Guinea. Politically they are divided between the Federated States of Micronesia in the eastern part of the group, and Palau at the extreme western end...

, Marshall islands

Marshall Islands

The Republic of the Marshall Islands , , is a Micronesian nation of atolls and islands in the middle of the Pacific Ocean, just west of the International Date Line and just north of the Equator. As of July 2011 the population was 67,182...

, Mariana Islands

Mariana Islands

The Mariana Islands are an arc-shaped archipelago made up by the summits of 15 volcanic mountains in the north-western Pacific Ocean between the 12th and 21st parallels north and along the 145th meridian east...

 and Palau

Palau

Palau , officially the Republic of Palau , is an island nation in the Pacific Ocean, east of the Philippines and south of Tokyo. In 1978, after three decades as being part of the United Nations trusteeship, Palau chose independence instead of becoming part of the Federated States of Micronesia, a...

 were heavily fortified to become “unsinkable aircraft carrier

Aircraft carrier

An aircraft carrier is a warship designed with a primary mission of deploying and recovering aircraft, acting as a seagoing airbase. Aircraft carriers thus allow a naval force to project air power worldwide without having to depend on local bases for staging aircraft operations...

s”, from which Japanese forces could sortie to inflict damage on any approaching fleet. The Japanese counted on these island outposts to wear down the approaching American fleet to a level to near parity where the Japanese Combined Fleet

Combined Fleet

The was the main ocean-going component of the Imperial Japanese Navy. The Combined Fleet was not a standing force, but a temporary force formed for the duration of a conflict or major naval maneuvers from various units normally under separate commands in peacetime....

 could meet them, and crush them in a decisive battle.

According to the first stage of the battle plan, fast attack submarines would first be used to weaken the American fleet by 10%, then Japanese bombers from land bases and aircraft carriers would inflict another 10% casualty rate. Air strikes launched from the Japanese carriers would neutralize the American carrier fleet. Fast attack battleships and heavy cruiser

Heavy cruiser

The heavy cruiser was a type of cruiser, a naval warship designed for long range, high speed and an armament of naval guns roughly 203mm calibre . The heavy cruiser can be seen as a lineage of ship design from 1915 until 1945, although the term 'heavy cruiser' only came into formal use in 1930...

s, likely operating at night, would then sink or scatter enemy cruiser and destroyer screening formations to allow massed light cruiser

Light cruiser

A light cruiser is a type of small- or medium-sized warship. The term is a shortening of the phrase "light armored cruiser", describing a small ship that carried armor in the same way as an armored cruiser: a protective belt and deck...

 and destroyer

Destroyer

In naval terminology, a destroyer is a fast and maneuverable yet long-endurance warship intended to escort larger vessels in a fleet, convoy or battle group and defend them against smaller, powerful, short-range attackers. Destroyers, originally called torpedo-boat destroyers in 1892, evolved from...

 attacks on the US battleships using long-distance torpedoes

Type 93 torpedo

The Type 93 was a -diameter torpedo of the Imperial Japanese Navy , launched from surface ships. It is commonly referred to as the Long Lance by most modern English-language naval historians, a nickname given it after the war by Samuel E. Morison, the chief historian of the U.S...

. According to plan, this moment would be the “decisive” stage of the decisive battle, when the battleships of the Combined Fleet, centered on the modern Yamato

Yamato class battleship

The were battleships of the Imperial Japanese Navy constructed and operated during World War II. Displacing at full load, the vessels were the heaviest and most powerfully armed battleships ever constructed. The class carried the largest naval artillery ever fitted to a warship, nine naval...

 class, would join the battle against the US battleships. Finally, the older battleships would join the fray and mop up the surviving remnants of the American fleet .

Flaws

Mahan's premise that a reserve force would be unable to recover after an initial overwhelming defeat was refuted by the US Navy's own recovery after the attack on Pearl Harbor

Attack on Pearl Harbor

The attack on Pearl Harbor was a surprise military strike conducted by the Imperial Japanese Navy against the United States naval base at Pearl Harbor, Hawaii, on the morning of December 7, 1941...

. The Japanese pursuit of the "decisive battle" was carried out to such an extent that it contributed to Japan's defeat

Surrender of Japan

The surrender of Japan in 1945 brought hostilities of World War II to a close. By the end of July 1945, the Imperial Japanese Navy was incapable of conducting operations and an Allied invasion of Japan was imminent...

 in 1945.

Japanese planners refused to abandon the kantai kessen doctrine, even after the Battle of Midway

Battle of Midway

The Battle of Midway is widely regarded as the most important naval battle of the Pacific Campaign of World War II. Between 4 and 7 June 1942, approximately one month after the Battle of the Coral Sea and six months after Japan's attack on Pearl Harbor, the United States Navy decisively defeated...

, which proved that decisive battles fought between fleets of battleships had become obsolete by the development of submarine

Submarine

A submarine is a watercraft capable of independent operation below the surface of the water. It differs from a submersible, which has more limited underwater capability...

s and aircraft carrier

Aircraft carrier

An aircraft carrier is a warship designed with a primary mission of deploying and recovering aircraft, acting as a seagoing airbase. Aircraft carriers thus allow a naval force to project air power worldwide without having to depend on local bases for staging aircraft operations...

s.

As Japan lost ground in the Pacific, Japanese naval planners continued to rely on the Americans to attempt to take every Japanese island outpost along the way to Japan. However, the Americans had already decided on a strategy of “island hopping

Island hopping

Island hopping is a term that refers to the means of crossing an ocean by a series of shorter journeys between islands, as opposed to a single journey directly across the ocean to the destination.- Forms :...

” in the Pacific, whereby the Americans bypassed islands not of strategic value, providing the Japanese fewer opportunities to wear down the American forces before the decisive battle. In addition, since Japanese forces had to spread thin in order to defend against many possible American invasions, the Americans had the initiative and were numerically superior to the Japanese at nearly every engagement.

In addition, the Japanese submarine force was not as effective as planned, and there was little hope of the submarine arm of the navy inflicting a 10% casualty rate on the American fleet .
Despite being one of the first countries to build aircraft carriers and a naval aviation arm, conservatives within the navy refused to accept naval aviation as anything more than reconnaissance

Reconnaissance

Reconnaissance is the military term for exploring beyond the area occupied by friendly forces to gain information about enemy forces or features of the environment....

 and artillery spotting for the battleship fleet. As a result, the Japanese equipped their fleet with the weapons to win a battle that they would likely never fight, putting them at an enormous disadvantage in the battles they did fight.

The Japanese investment in battleships also meant other branches of the fleet, particularly destroyer escort

Destroyer escort

A destroyer escort is the classification for a smaller, lightly armed warship designed to be used to escort convoys of merchant marine ships, primarily of the United States Merchant Marine in World War II. It is employed primarily for anti-submarine warfare, but also provides some protection...

s used to protect shipping, were neglected . As a result, the Japanese suffered substantial losses in shipping to American submarines, resulting in an enormous strain for resources for the Japanese war machine.

On the other hand, Japan's success at Pearl Harbor conversely forced the American navy to take steps towards establishing the world's first carrier-based naval doctrine. (Lowe 2005). The American dependence upon their aircraft carriers played a large role in the Battle of Midway

Battle of Midway

The Battle of Midway is widely regarded as the most important naval battle of the Pacific Campaign of World War II. Between 4 and 7 June 1942, approximately one month after the Battle of the Coral Sea and six months after Japan's attack on Pearl Harbor, the United States Navy decisively defeated...

, and American air superiority in the Pacific eventually doomed the Japanese in later battles. Where deployed, the Japanese battleships proved extremely vulnerable to air attack.

Opposition

Admiral Isoroku Yamamoto

Isoroku Yamamoto

was a Japanese Naval Marshal General and the commander-in-chief of the Combined Fleet during World War II, a graduate of the Imperial Japanese Naval Academy and a student of Harvard University ....

 led the opposition to the kantai kessen doctrine in the Japanese navy. Contrary to other naval officers, Yamamoto claimed that building huge battleships such as Yamato and Musashi was pointless, as that no ship was unsinkable, saying “The fiercest serpent may be overcome by a swarm of ants”. According to Yamamoto, carrier-based airplanes would be the deadly swarm of ants in the new war. He believed it unlikely the Japanese and American navies would ever engage in a battleship engagement. Instead, he believed the struggle in the Pacific would be for control of the skies as naval aviation can project firepower to much greater distances than battleships. However, Yamamoto was killed on April 18, 1943, and with his death came the death of the staunchest advocate of naval aviation in the Japanese navy.

As the war progressed, other officers came to question other aspects of the Kantai Kessen Doctrine; for example, Admiral Matome Ugaki asked, “I wonder why they don't give enough consideration to attacking enemy elements easy to destroy, instead of always seeking a decisive battle?” . Ugaki advocated smaller engagements of concentrated forces to pick off weak elements of the American navy instead of attempting to destroy the entire fleet at once.

In Practice

The naval battles of the Coral Sea

Battle of the Coral Sea

The Battle of the Coral Sea, fought from 4–8 May 1942, was a major naval battle in the Pacific Theater of World War II between the Imperial Japanese Navy and Allied naval and air forces from the United States and Australia. The battle was the first fleet action in which aircraft carriers engaged...

 and Midway represented a departure from the traditional doctrine of kantai kessen . Planned by Yamamoto, these battles aimed at achieving decisive victories to knock the American fleet out of the war at an early stage. However, failure to secure a decisive victory at the Coral Sea, and the disastrous defeat at the Battle of Midway ended Yamamoto's plans for an aggressive, offensive strategy. Rather than reorganize the fleet around three carrier groups similar to the USN Task Forces, as had been argued by Rear Admiral Tamon Yamaguchi even before Midway, the Japanese Navy General Staff refused to accept the subordination of battleships to aircraft carriers and reverted to the more conservative defensive strategy within the doctrine of kantai kessen

For most of 1943, Japan focused on preparing perimeter defenses to stand up to the coming American offensives. The Japanese defensive perimeter was such that the Marshall Islands

Marshall Islands

The Republic of the Marshall Islands , , is a Micronesian nation of atolls and islands in the middle of the Pacific Ocean, just west of the International Date Line and just north of the Equator. As of July 2011 the population was 67,182...

 and Gilbert Islands

Gilbert Islands

The Gilbert Islands are a chain of sixteen atolls and coral islands in the Pacific Ocean. They are the main part of Republic of Kiribati and include Tarawa, the site of the country's capital and residence of almost half of the population.-Geography:The atolls and islands of the Gilbert Islands...

 were left outside of the area to which the Japanese were willing to commit the Combined Fleet to defend. The Americans thus took these two island groups without significant resistance from the Combined Fleet

After the capture of the Marshalls in early 1944, the Japanese sought the decisive victory in the Marianas . Contrary to the Marshall Islands, the Japanese deemed the Marianas vital enough to commit the Combined Fleet. In the Battle of the Philippine Sea

Battle of the Philippine Sea

The Battle of the Philippine Sea was a decisive naval battle of World War II which effectively eliminated the Imperial Japanese Navy's ability to conduct large-scale carrier actions. It took place during the United States' amphibious invasion of the Mariana Islands during the Pacific War...

, also known as the “Great Marianas Turkey Shoot,” the Japanese lost over 400 aircraft and three of nine aircraft carriers, effectively crushing the Japanese carrier force in the Pacific . While the Japanese plans had intended for the American fleet to gradually be ground down during the American offensives across the Pacific, in actuality it was the Japanese Fleet which lost irreplaceable aircraft carriers, planes, and pilots, reducing their ability to win any battle, let alone a decisive battle against the American fleet. However, the Japanese did not alter their strategy and made one last great attempt to achieve a decisive naval victory during the defense of the Philippines.

The Japanese knew that in order to continue the war, the Philippines

Philippines

The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...

 needed to be held against American invasion. If the Philippines were to fall, then Japanese supply lines to the oil fields of Southeast Asia

Southeast Asia

Southeast Asia, South-East Asia, South East Asia or Southeastern Asia is a subregion of Asia, consisting of the countries that are geographically south of China, east of India, west of New Guinea and north of Australia. The region lies on the intersection of geological plates, with heavy seismic...

 would be severed and Japan's fleet and industries would be unable to continue the war . Therefore, the Japanese committed the entire Combined Fleet, despite lack of sufficient air support, in a last desperate attempt for a decisive victory. Beginning October 24, 1944, the fleets engaged in the Battle of Leyte Gulf

Battle of Leyte Gulf

The Battle of Leyte Gulf, also called the "Battles for Leyte Gulf", and formerly known as the "Second Battle of the Philippine Sea", is generally considered to be the largest naval battle of World War II and, by some criteria, possibly the largest naval battle in history.It was fought in waters...

, one of the largest naval battles in history. The battle was a decisive battle, but with Japan on the losing end, as the bulk of the remaining combat effective force of the Combined Fleet was annihilated in the Battle of Leyte Gulf, and the Imperial Japanese Navy unable to recover.

In the end, the Japanese search for a decisive battle which to turn the course of the war based on a battleship–to-battleship combat was futile since the American carriers refused to allow the Japanese battleships to get within range. The decisive battle was indeed fought, not with battleships as envisioned under the kantai kessen, but with naval aviation.