In the autumn of the 2,600th
year (1940) of the founding of the Japanese Empire, Kinoaki Matsuo published a
book on how Japan planned to defend itself in a war with the United States. The
United States - Japanese War, written by this intelligence officer when
serving as liaison between the Japanese Foreign Office and the Admiralty,
openly discussed the impending hostilities. He wrote:
|
..." the United States
will be obliged to exercise prudence and self-restraint toward Japan at least
until 1945." "As soon as the great
armament expansion is completed, the United States will probably avail
herself of the opportunity to declare war upon Japan... then the chances of
American victory will be far greater
than Japan's." He stated, "Japan is naturally blessed by double
defensive walls linked inside and outside by a chain of islands. The inside link consists of the Shochu
Islands, Taiwan, all islands to the west and south, the Ogasawara Islands,
and the Chishima Islands, all of which have already been strongly armed for
defense." "The outside link (Nan-yō Gunto) extends
many thousands of nautical miles embracing the Marshalls, Carolines, Marianas
and Berau islands, which are scattered like stars across the routes of the United States Navy either
perpendicularly or horizontally. The total number of these islands is more
than one thousand. It will be impossible for the United States fleet to reach
its destination...." "The tragedy which will
ensue as a result of the failure of the United States fleet in its attempt to
cross the Pacific can be imagined by recalling the end of the Russian Baltic
Fleet in the Sea of Japan." |
Fortunately for both sides, such
hypothetical war never started. But Kinoaki vision is still the base of the
naval doctrine of the IJN. After the lost of its continental possesions, Japan
has focused its efforts mostly around its naval and aerial assets. The
operational use of Imperial Japanese Naval Aviation has been designed around
the Imperial Japanese Navy strategic and operational plan to respond to a US or
Soviet Naval thrust to the Home Islands and force a decisive battle on Japanese terms.
The IJN recognized the US Navy as its
primary foe from the end of the Russo-Japanese War in 1905. From 1920, the IJN
began to craft a strategic and operational plan for countering a US Navy thrust
into the Western Pacific. The Soviet Pacific Fleet, concentrated in Vladivostok
and Lüshun, could disrupt the Japanese Sea Lanes
of Communication (SLOC) momentarily, but represented a secondary threat, due to
the concentration of Soviet’s military efforts in its air and ground forces
vis-ą-vis Germany and China.
Japan's naval and aerial building program
has been designed around the operational and tactical needs for executing this
doctrinal plan. The U.S. Navy will come west –or the Soviet Navy will come
east– and the IJN had to be prepared to stop them. Japanese scenarios start
with an attack on the enemy possessions and forces in the western Pacific, with
or without a declaration of war. It is expected the U.S. Navy to mount an
expedition, sooner or later, to relieve or recover Guam or its bases in the
Philippines. From Nan-yō Gunto, the IJN plans to enmesh the U.S. Navy within
these islands in a campaign of attrition by Japanese light forces. When the
U.S. force had been sufficiently weakened, the Battle Force would sail from the
Sea of Japan and execute the "coup de grace". In the case of a Soviet
attack, the IJN plans to use its Naval Aviation from its carriers and ground
bases, in long range attacks against Vladivostok and Port Arthur, that could or could not be
followed by a blockade.
Possession of Karafuto and the Chishima-retto is also extremely important
from a strategic standpoint, allowing Japan to almost completely control the
primary sea lanes connecting the southern half of the Soviet Far East with the
rest of the world, and to threaten the Pacific possessions of the U.S. Japan
maintains numerous military installations on Karafuto and the Chishima islands,
and stations a relatively large military garrison there.
The IJN envisions its light forces as
consisting of land based aviation, carrier based aviation, heavy and light destroyers,
frigates and submarines, along with some special systems "cooked up"
especially for this hypothetical campaign. Submarines would make the initial
contact. They would shadow the U.S. force and guide other submarines and the
land based aviation to the target. The submarines would begin to probe the U.S.
perimeter to distract U.S. forces from the oncoming bombers and ASW planes. The
submarines would also scatter mines and miniature subs in the US force's path.
Japanese destroyers and frigates would conduct long-range missile attacks with
"Long Lances" missiles. The IJN has built special missile frigates
with 40 tubes installed, quick reload gear for missiles on their frigates and
destroyers and practice hard at these tactics.
The IJN plans to use their CVs in single
carrier task forces with heavy support of frigates, destroyers and submarines.
The fighters will swept the skies over the invaders, and the strike force will
concentrated initially on the U.S. CVs. Once the U.S. naval aviation is broken
and air superiority secured, denying use of the skies by the U.S. planes and
securing its use by the Japanese, the missile boats will come forward, and
using its anti-ship weapons engage in a long range missile duel. Once the
culminating point was reached, the Battle Force would close in on and destroy
the invaders. Meanwhile, the subs would be eliminating any wounded vessels,
which left formation and tried to reach enemy ports. With the enemy forces
broken, the remaining IJN light forces, including the carriers and missile frigates
will pursue and complete the enemy's destruction.
* * *
The Imperial Japanese Air Army maintains
an almost subordinate position to the IJN, and its principal purpose, besides
the Empire’s aerial defense is to provide protection to the IJN units. The IJA,
since the Soviet-Japanese War, has been relegated to
serve as a counter-invasion force, excepting in the Nan-yo Gunto Special Prefecture, where this mission is
commended to the Imperial Japanese Naval Infantry (IJNI).
* * *
The IJA doctrine 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 20,000 kilometer coastline
of the five 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, the IJA 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 Japan’s maritime defense, will enable
the Empire to maintain solid defense posture required for effective deterrence
against an aggression.
As Japan's warheads became smaller and missile accuracies improved,
Japan changed from a 1960´s “minimal deterrence” doctrine (which requires only
a small number of warheads to inflict unacceptable damage on an enemy's
cities), towards a doctrine of “limited deterrence”. Under limited deterrence
Japan is able to inflict enough counterforce and countervalue damage on the
enemy such that it backs down and is thus denied victory. Several overarching strategic wartime missions would
require:
- disruption and destruction of the enemy's essential command, control,
and communications capabilities and reconnaissance means;
- destruction or neutralization of enemy nuclear forces on the ground or
at sea before they could be launched; and
- protection of the Japanese leadership and cadres, military forces,
military and economic assets necessary to sustain the war and the general
population.
- strategic and theatre forces and programs in place or under active
development designed to accomplish these objectives include:
- hard-target-capable ICBMs, new submarine-launched ballistic missiles
(SLBMs), Longer Range Intermediate-Range Nuclear Forces (LRINF) ballistic
missiles, and land-based cruise missiles;
-shorter range INF (SRINF) and short range nuclear forces (SNF) systems
deployed with combat troops;
- large numbers of land-attack and antiship cruise missiles on various
platforms;
- antisubmarine warfare (ASW) forces to attack enemy nuclear-powered
ballistic missile submarines (SSBNs) and protect Japanese SSBNs;
-air and missile defenses, including early warning satellites and
radars, interceptor aircraft, surface-to-air missiles (SAMs), antiballistic
missile (ABM) radars and interceptors, and some antiaircraft artillery;
- antisatellite weapons;
- passive defense forces, including civil defense forces and countermeasures
troops and equipment devoted to confusing incoming aircraft;
- hardened facilities numbering in the thousands, command vehicles, and
evacuation plans designed to protect party, military, governmental, and
industrial staffs, essential workers and, to the extent possible, the general
population; and
- varied and redundant communications networks.
Supporting a naval war in the Western Pacific and eliminating enemy
capacity to fight and support a conflict would require the capability to employ
theater and strategic forces over a variety of ranges and the destruction
of:
- military-associated command-and-control assets;
- war-supporting industries, arsenals, and major military facilities;
- ports and airfields in enemy territory and along air and sea routes to
the theatres of war; and
- satellite surveillance sensors, ground-based surveillance sensors, and
related communications facilities.
The historic and continuing objective of Japan’s strategic forces is
deterrence of nuclear and conventional aggression against the Imperial
Homeland, its allies, and friends. This policy has preserved peace and is based
on the conviction widely held in Japan that no winners would emerge from a
nuclear conflict.
Japan does not have a strategic first-strike policy. Moreover, Japan has
no plans to adopt a first-strike policy or plans to acquire a first-strike
capability in the future. Rather, Japanese deterrence policy seeks to maintain
the situation in which any potential aggressor sees little to gain and much to
lose by initiating hostilities against Japan or its allies. In turn, the
maintenance of peace through deterrence provides the vital opportunity to
pursue Japan’s goal of eliminating nuclear weapons from the arsenals of all
states.
To realize these deterrence objectives requires the development,
deployment, and maintenance of strategic forces whose size and characteristics
clearly indicate to an opponent that politico-military objectives cannot be
achieved through employment of nuclear weapons or through political coercion
based on nuclear advantages. In the Theatre Missile Defence program,
Japan is now investigating the potential over the long term of basing deterrence
increasingly on defensive systems.
