Re-Establishing Japan's Intelligence Capability – 'Spy Paradise' lost?
RUSI Commentary
10 juin 2026, 02:00
Texte de la source originale
Chapter
1
Basic Concepts of Japan’s Security and Defense
Constitution and the Basis of Defense Policy
❶ Constitution and the Right of Self-Defense ●
Since the end of World War II, Japan made a decision not
to repeat the ravages of war and has worked hard to build
a peace-loving nation. The Japanese people desire lasting
peace, and the principle of pacifism is enshrined in the
Constitution, Article 9 of which prescribes the renunciation
of war, the prohibition of war potential, and the denial of the
right of belligerency of the state. Of course, since Japan is
an independent nation, these provisions do not deny Japan’s
inherent right of self-defense as a sovereign state. Thus, the
Japanese Government interprets this as a constitutional right
to possess the minimum armed forces needed to exercise that
right. Therefore, Japan, under the Constitution, maintains
the Self-Defense Forces (SDF) as an armed organization,
holding its exclusively defense-oriented policy as its basic
strategy of defense, and continues to keep it equipped and
ready for operations.
❷ The Government’s View on Article 9 of the Constitution ●
1 Permitted Self-Defense Capability
Under the Constitution, Japan is permitted to possess the
required minimum self-defense capability. The specific limit
is subject to change according to the prevailing international
situation, the level of military technologies, and various other
factors, and it is discussed and decided through annual budget
and other deliberations by the Diet on behalf of the people.
Whether such capability constitutes a “war potential” that is
prohibited by Article 9, Paragraph 2 of the Constitution must
be considered within the context of Japan’s overall military
strength. Therefore, whether the SDF should be allowed
to possess certain armaments depends on whether such
possession would cause its total military strength to exceed
the constitutional limit.
The possession of armaments deemed to be offensive
weapons designed to be used only for the mass destruction
of another country is not permissible under any circumstance
as it would, by defi nition, exceed the minimum necessary
level. For example, the SDF is not allowed to possess
intercontinental ballistic missiles (ICBM), long-range
strategic bombers, or attack aircraft carriers.
2 Measures for Self-Defense Permitted under Article
9 of the Constitution
In the past, the Government had interpreted Article 9 of
the Constitution to mean that armed force could be used to
exercise the right of self-defense only when the following
three conditions (Three Conditions for “Use of Force”) were
met: (1) When there is an imminent and illegitimate act of
aggression against Japan; (2) When there are no appropriate
means to deal with such aggression other than by resorting to
the right of self-defense; and (3) When the use of armed force
is confi ned to be the minimum necessary level. However, it
has been concluded in the Cabinet’s decision made on July
1, 2014, “Development of Seamless Security Legislation to
Ensure Japan’s Survival and Protect its People,” that “the
use of force” should be interpreted to be permitted under the
Constitution as measures for self-defense when the following
“Three New Conditions” are met: (1) When an armed attack
against Japan has occurred, or when an armed attack against
a foreign country that is in a close relationship with Japan
occurs and as a result threatens Japan’s survival and poses
a clear danger to fundamentally overturn people’s right to
life, liberty and pursuit of happiness; (2) When there is no
appropriate means available to repel the attack and ensure
Japan’s survival and protect its people; (3) Use of force to the
minimum extent necessary. The following is the interpretation
of the measures for self-defense permitted under Article 9
of the Constitution defi ned in the abovementioned Cabinet
decision.
The language of Article 9 of the Constitution appears
to prohibit “use of force” in international relations in all
forms. However, when considered in light of “the right (of
the people) to live in peace” as recognized in the Preamble
of the Constitution and the purpose of Article 13 of the
Constitution which stipulates, “their (all the people’s) right
to life, liberty, and the pursuit of happiness” shall be the
supreme consideration in governmental affairs, Article 9 of
the Constitution cannot possibly be interpreted to prohibit
Japan from taking measures of self-defense necessary to
maintain its peace and security and to ensure its survival.
Such measures for self-defense are permitted only when they
are inevitable for dealing with imminent unlawful situations
where the people’s right to life, liberty, and the pursuit of
Section
2
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happiness is fundamentally overturned due to an armed
attack by a foreign country, and for safeguarding these rights
of the people. Hence, “use of force” to the minimum extent
necessary to that end is permitted. This is the basis, or the
so-called basic logic, of the view consistently expressed
by the government to date with regard to “use of force”
exceptionally permitted under Article 9 of the Constitution,
and clearly shown in the document “Relationship between
the Right of Collective Self-Defense and the Constitution”
submitted by the Government to the Committee on Audit of
the House of Councillors on October 14, 1972.
This basic logic must be maintained under Article 9 of the
Constitution.
To date, the Government has considered that “use of
force” under this basic logic is permitted only when an
“armed attack” against Japan occurs. However, in light of
the situation in which the security environment surrounding
Japan has been fundamentally transformed and continuously
evolving by shifts in the global power balance, the rapid
progress of technological innovation, and threats such as
weapons of mass destruction, etc., in the future, even an
armed attack occurring against a foreign country could
actually threaten Japan’s survival, depending on its purpose,
scale and manner, etc.
Japan, as a matter of course, will make the utmost
diplomatic efforts, should a dispute occur, for its peaceful
settlement and take all necessary responses in accordance
with the existing domestic laws and regulations developed
based upon the constitutional interpretation to date. It is still
required, however, to make all necessary preparations in
order to ensure Japan’s survival and protect its people.
Under such recognition and as a result of careful
examination in light of the current security environment,
it has been concluded that not only when an armed attack
against Japan occurs but also when an armed attack against
a foreign country that is in a close relationship with Japan
occurs and as a result threatens Japan’s survival and poses
a clear danger to fundamentally overturn people’s right to
life, liberty and pursuit of happiness, and when there is no
other appropriate means available to repel the attack and
ensure Japan’s survival and protect its people, use of force
to the minimum extent necessary should be interpreted to be
permitted under the Constitution as measures for self-defense
in accordance with the basic logic of the Government’s view
to date.
As a matter of course, Japan’s “use of force” must be
carried out while observing international law. At the same
time, a legal basis in international law and constitutional
interpretation need to be understood separately. In certain
situations, the aforementioned “use of force” permitted under
the Constitution is, under international law, based on the
right of collective self-defense. The Government has reached
a conclusion that although this “use of force” includes those
which are triggered by an armed attack occurring against a
foreign country, they are permitted under the Constitution,
only when they are taken as measures for self-defense which
are inevitable for ensuring Japan’s survival and protecting its
people, in other words, for defending Japan.
3 Geographic Boundaries within Which the Right of
Self-Defense May Be Exercised
The use of the minimum necessary force to defend Japan
under the right of self-defense is not necessarily confined to
the geographic boundaries of Japanese territory, territorial
waters, and airspace. However, it is difficult to give a general
definition of the actual extent to which it may be used, as this
would vary with the situation.
Nevertheless, the Government interprets that, as a general
rule, the Constitution does not permit armed troops to be
dispatched to the land, sea, or airspace of other countries with
the aim of using force; such overseas deployment of troops
would exceed the definition of the minimum necessary level
of self-defense.
4 Right of Belligerency
Article 9, Paragraph 2 of the Constitution prescribes that “the
right of belligerency of the state will not be recognized.”
However, the “right of belligerency” does not mean the right
to engage in battle; rather, it is a general term for various
rights that a belligerent nation has under international law,
including the authority to inflict casualties and damage upon
the enemy’s military force and to occupy enemy territory.
On the other hand, Japan may of course use the minimum
level of force necessary to defend itself. For example, if
Japan inflicts casualties and damage upon the enemy’s
military force in exercising its right of self-defense, this is
conceptually distinguished from the exercise of the right of
belligerency, even though those actions do not appear to be
different. Occupation of enemy territory, however, would
exceed the minimum necessary level of self-defense and is
not permissible.
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❸ Basic Policy ●
1 Article 2 of the Atomic Energy Basic Law states that “The research, development and utilization of atomic energy shall be limited to peaceful purposes, aimed at ensuring safety and
performed independently under democratic management.”
2 Article 2 of the NPT states that “Each non-nuclear-weapon State Party to the Treaty undertakes...not to manufacture or otherwise acquire nuclear weapons or other nuclear explosive
devices...”
3 The Cabinet’s control over military matters was strictly limited.
Under the Constitution, Japan has efficiently built a highly
effective and joint defense force in line with the basic
principles of maintaining an exclusively defense-oriented
policy and not becoming a military power that poses a threat
to other countries, while firmly maintaining the Japan-U.S.
Security Arrangements and adhering to the principle of
civilian control of the military, observing the Three Non-
Nuclear Principles.
1 Exclusively Defense-Oriented Policy
The exclusively defense-oriented policy means that
defensive force is used only in the event of an attack, that the
extent of the use of defensive force is kept to the minimum
necessary for self-defense, and that the defense capabilities
to be possessed and maintained by Japan are limited to the
minimum necessary for self-defense. The policy including
these matters refers to the posture of a passive defense
strategy in accordance with the spirit of the Constitution.
2 Not Becoming a Military Power
There is no established definition for the concept of a military
power. For Japan, however, not becoming a military power
that could threaten other countries means that Japan will not
possess and maintain a military capability strong enough
to pose a threat to other countries, beyond the minimum
necessary for self-defense.
3 Non-Nuclear Principles
The Three Non-Nuclear Principles refers to those of not
possessing nuclear weapons, not producing them, and not
allowing them to be brought into Japan. Japan adheres to
the Three Non-Nuclear Principles as a fixed line of national
policy.
Japan is also prohibited from manufacturing and
possessing nuclear weapons under the Atomic Energy Basic
Law.1 In addition, Japan ratified the Treaty on the Non-
Proliferation of Nuclear Weapons (NPT), and as a non-
nuclear weapons state, has an obligation not to manufacture
and acquire nuclear weapons.2
4 Securing Civilian Control
Civilian control refers to the priority of politics to the
military in a democratic state or democratic political control
of military strength. Japan has, by giving serious reflection
to the regrettable state of affairs that happened until the
end of World War II, adopted the following strict civilian
control system that is entirely different from the one under
the former Constitution.3 Civilian control aims to ensure that
the SDF is maintained and operated in accordance with the
will of the people.
The Diet, which represents Japanese nationals, makes
legislative and budgetary decisions on such matters
as the allotted number of the SDF personnel and main
organizations of the Ministry of Defense (MOD)/SDF. It
also issues approval for defense operations of the SDF. The
function of national defense entirely falls under the executive
power of the Cabinet as a general administrative function.
The Constitution requires that the Prime Minister and other
Ministers of State who constitute the Cabinet be civilians.
The Prime Minister, on behalf of the whole Cabinet, holds
the authority of supreme command and supervision of the
SDF. The Minister of Defense, who is exclusively in charge
of national defense, exercises general control and supervises
over the SDF duties. In addition, the National Security
Council of Japan under the Cabinet deliberates important
Prime Minister Abe giving instructions upon the departure ceremony for the destroyer dispatched
to the Middle East for information gathering [Website of the Prime Minister's Office of Japan]
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matters on national security.4
At the MOD, the Minister of Defense takes charge of
and manages the matters concerning national defense, and
as the competent minister also manages and operates the
SDF. The Minister of Defense is assisted in policy planning
and political affairs by the State Minister of Defense, the
Parliamentary Vice-Ministers of Defense (two) and the
Senior Adviser to the Minister of Defense.
In addition, the Special Adviser to the Minister of Defense
provides the Minister of Defense with advice on important
affairs under the jurisdiction of the MOD based on their
expertise and experience. The Defense Council consisting
4 See Chapter 2, Section 1
of political appointees, civilian officials and uniformed SDF
personnel deliberates on basic principles concerning affairs
under the Ministry’s jurisdiction. Through these ways, the
MOD aims to further ensure civilian control.
As mentioned above, the civilian control system is well
established. However, in order to ensure that the system
achieves good results, it is necessary to continue making
practical efforts in both political and administrative aspects,
along with a deep interest in national defense taken by the
people.
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