Defenses and Global Instability
by David Krieger*, April 2001
In the world
of nuclear deterrence theory, beliefs are everything. What the
leaders of a country perceive and believe is far more important
than the reality. Nuclear deterrence is a seemingly simple proposition:
Country A tells country B that if B does X, A will attack it with
nuclear weapons. The theory is that country B will be deterred
from doing X by fear of nuclear attack by country A. For deterrence
to work, the leaders of country B must also believe that country
A has nuclear weapons and will use them. Nuclear deterrence theory
holds that even if country A might not have nuclear weapons, so
long as the leaders of country B believed that it did they would
The theory goes on to hold that country A can generally
rely upon nuclear deterrence with any country except one that
also has nuclear weapons or one that is protected by another country
with nuclear weapons. If country B also has nuclear weapons and
the leaders of country A know this, then A, according to theory,
will be deterred from a nuclear attack on country B. This situation
will result in a standoff. The same is true if country C does
not have nuclear weapons, but is under the "umbrella"
of country B that does have nuclear weapons. Country A will not
retaliate against country C for fear of itself being retaliated
against by country B.
Thus, if country A has nuclear weapons and no other
country has nuclear weapons, country A has freedom -- within the
limits of its moral code, pressures of public opinion, and its
willingness to flout international humanitarian law -- to threaten
or use nuclear weapons without fear of retaliation in kind. For
a short time the United States was the only country with nuclear
weapons. It used these weapons twice on a nearly defeated enemy.
Deterrence played no part. The United States never said to Japan,
don't do this or we will attack you with nuclear weapons. Prior
to using the nuclear weapons, these weapons were a closely guarded
From 1945 to the early 1950s, US strategic thinking
saw free-fall nuclear weapons simply extending conventional bombing
capabilities. The United States never said that it would attack
another country with nuclear weapons if it did X, but this was
implied by the recognized existence of US nuclear weapons, the
previously demonstrated willingness of the US to use them, and
the continued public testing of these weapons by the US in the
The Dangerous Game of Deterrence
After the Soviet Union tested its first nuclear
weapon in 1949, the dangerous game of nuclear deterrence began.
Both the US and USSR warned that if attacked by nuclear weapons,
they would retaliate in kind massively. They also extended their
respective so-called nuclear deterrence "umbrellas"
to particular countries within their orbits. As the arsenals of
each country grew, they developed policies of Mutual Assured Destruction.
Each country had enough weapons to completely destroy the other.
Britain and France also developed nuclear arsenals because they
did not want to rely upon the US nuclear umbrella, and to try
to preserve their status as great powers. They worried that in
a crisis the US might not come to their aid if it meant that the
US risked annihilation by the USSR for doing so. China also developed
a nuclear arsenal because it felt threatened by both the US and
USSR. Israel, India, Pakistan and South Africa also developed
nuclear arsenals, although South Africa eventually dismantled
its small nuclear arsenal.
Nuclear deterrence took different shapes with different
countries. The US and USSR relied upon massive retaliation from
their large arsenals of tens of thousands of nuclear weapons.
The UK, France and China maintained smaller deterrent forces of
a few hundred nuclear weapons each. India and Pakistan tested
nuclear weapons and missile delivery systems, but it is uncertain
whether they have yet deployed nuclear weapons. Israel, known
to have some 200 nuclear weapons, offers only the ambiguous official
statement that it will not be the first to introduce nuclear weapons
into the Middle East.
One obvious way that nuclear deterrence could fail
is if one side could destroy the other side's nuclear forces in
a first strike. To prevent this from happening, nuclear armed
states have tried to make their nuclear forces invulnerable to
being wiped out by a first strike attack. One way of doing this
was to put the weapons underground, in the air and in the oceans.
Many of the weapons on land were put in hardened silos, while
those in the oceans were put on submarines that were difficult
to locate underwater. For decades the strategic bombers of the
US and USSR carrying nuclear weapons were kept constantly on alert
with many in the air at any given moment.
Nuclear deterrence became a game of sorts - a dangerous
and potentially tragic one and also deeply selfish, irresponsible
and lawless, risking all humanity and the planet. Countries had
to protect their deterrence forces at all costs and not allow
themselves to become vulnerable to a first strike attack on their
nuclear forces. In a strange and perverse way, nuclear-armed countries
became more committed to protecting their nuclear forces than
they were to protecting their citizens. While they hardened their
land-based missile silos and placed their submarines in the deep
oceans, their citizens remained constantly vulnerable to nuclear
The game of nuclear deterrence required that no
country become so powerful that it might believe that it could
get away with a first strike attempt. It was this concern that
drove the nuclear arms race between the US and USSR until the
USSR was finally worn down by the economic burden of the struggle.
It also ensured a high level of hostility between rival nuclear-armed
countries, with great danger of misunderstandings - witness, for
example, the Cuban missile crisis and many other less well-known
scares. Mutual Assured Destruction lacked credibility, requiring
the development of policies of "Flexible Response,"
which lowered the nuclear threshold, encouraged the belief that
nuclear weapons could be used for war-fighting, increased the
risk of escalation to all-out nuclear war, and stimulated more
Notice that a first strike doesn't require that
one country actually have the force to overcome its opponent's
nuclear forces. The leaders of the country only have to believe
that it can do so. If the leaders of country A believe that country
B is planning a first strike attack, country A may decide to initiate
a preemptive strike. If the leaders of country A believe that
the leaders of country B would not initiate a nuclear attack against
them if they did X, then they might well be tempted to do X. They
might be mistaken. This led to the "launch-on-warning"
hair-trigger alert status between the US and Russia. More than
ten years after the end of the Cold War, each country still has
some 2,250 strategic warheads ready to be fired on a few moments'
notice. Nuclear deterrence operates with high degrees of uncertainty,
and this uncertainty increases, as does the possibility of irrationality,
in times of crisis.
Ballistic Missile Defenses
President George W. Bush cites as his primary reason
for wanting a ballistic missile defense system for the US his
lack of faith that nuclear deterrence would work against so-called
"rogue" states. Yet, the uncertainty in nuclear deterrence
increases when ballistic missile defenses are introduced. If country
A believes that it has a perfect defense against country B, then
country B may also believe that it has lost its deterrent capability
against country A. Ballistic missile defenses, therefore, will
probably trigger new arms races. If countries A and B each have
500 nuclear warheads capable of attacking the other, both are
likely to believe the other side will be deterred from an attack.
If country A attempts to introduce a defensive system with 1,000
anti-ballistic missile interceptors, country B may believe that
its nuclear-armed ballistic missile force will be made impotent
and decide to increase its arsenal of deliverable warheads from
500 to 2,000 in order to restore its deterrent capability in the
face of B's 1,000 defensive interceptors. Or, country B may decide
to attack country A before its defensive force becomes operational.
If country A plans to introduce a defensive system
with only 100 interceptors, country B might believe that its nuclear
force could still prevail with 500 deliverable nuclear weapons.
But country B must also think that country A's interceptors would
give A an advantage if A decides to launch a first strike attack
against B's nuclear forces. If country A is able to destroy 400
or more of country B's nuclear weapons, then A would have enough
interceptors (if they all worked perfectly) to believe that it
could block any retaliatory action by B. Thus, any defensive system
introduced by any country would increase instability and uncertainty
in the system, making deterrence more precarious. Worse, this
introduces a fear that ballistic missile defense has little to
do with defense, and far more to do with an offensive "shield"
behind which a country could believe that it could coerce the
rest of the world with impunity.
It was concern for the growing instability of nuclear
deterrence to the point where it might break down that led the
US and USSR to agree in 1972 to place limits on defensive missile
forces in the Anti-Ballistic Missile (ABM) Treaty. In this treaty
each side agreed to limit its defensive forces to no more than
two sites of 100 interceptors each. These sites could not provide
protection to the entire country. It is this treaty that the United
States is now seeking to amend or unilaterally abrogate in order
to build a national ballistic missile defense. It claims this
defense is needed to protect itself against so-called "rogue"
states such as North Korea, Iran or Iraq. At present, however,
none of these countries is even expected to be able to produce
nuclear weapons or a missile delivery system capable of reaching
the United States before 2010 at the earliest.
Russia and China have both expressed strong opposition
to the US proceeding with ballistic missile defense plans. Russia
wants to maintain the ABM Treaty for the reasons the treaty was
initially created, and is aghast at comments from the US such
as those of Secretary of Defense Rumsfeld calling the treaty "ancient
history." Russia is also seeking to reduce the size of its
nuclear arsenal for economic reasons and its leaders fear the
instabilities that a US national ballistic missile defense system
would create. Russian leaders have said that such a system that
abrogated the ABM Treaty could result in Russia withdrawing from
other arms control treaties including the START II and the Comprehensive
Test Ban Treaty.
China has a nuclear force a fraction of that of
Russia or the US. It has some 400 nuclear weapons, but only some
20 long-range missiles capable of reaching the US. If the US sets
up a system of some 100 to 200 interceptors, China would have
to assume that its nuclear deterrent capability had been eliminated.
Chinese leaders have called for the US not to go ahead with a
ballistic missile defense system that would force China to develop
a stronger nuclear deterrent force. Were China to do so, this
would inevitably provoke India to expand its nuclear capability,
which in turn would lead Pakistan to do the same.
At a time when major progress toward nuclear disarmament
is possible and even promised by the nuclear weapons states, the
US desire to build a ballistic missile defense system to protect
it against small nuclear forces is introducing new uncertainties
into the structure of global nuclear deterrence and increasing
the instability in the system. Nuclear deterrence has never been
a stable system. One country's nuclear strategies have both predictable
and unpredictable consequences in other countries.
Security built upon nuclear arms cannot endure.
US nuclear weapons led to the development of the USSR and UK nuclear
arsenals. These led to the development of the French and Chinese
nuclear forces. The Chinese nuclear forces led to the development
of Indian nuclear forces. India's nuclear forces led to the development
of Pakistani nuclear forces. Israel decided to develop nuclear
forces to give it a deterrent among hostile Middle East neighbors.
No doubt this provoked Saddam Hussein - and gave him the pretext
- to develop Iraq's nuclear capability, and is driving Iran to
Now the US is seeking to introduce national and
theater ballistic missile defenses that will provide further impetus
to nuclear arms development and proliferation. The world is far
more complicated than country A deterring country B by threat
of nuclear retaliation. As more countries develop nuclear arsenals,
more uncertainties enter the system. As more defenses are set
in place, further uncertainties enter the system. While the US
seeks to make itself invulnerable against threats that do not
yet even exist, it is further destabilizing the existing system
of global nuclear deterrence to the point where it could collapse
- especially when the President demonstrates his belief that the
system can no longer be relied upon.
The full consequences of US missile defense plans
are not predictable. What is predictable is that the introduction
of more effective defenses by the US will change the system and
put greater stress on the global system of security built upon
nuclear deterrence. The system is already showing signs of strain.
With new uncertainties will come new temptations for a country
to use nuclear forces before they are used against it. Nuclear
deterrence is not sustainable in the long run, and we simply don't
know what stresses or combination of perceptions and/or misperceptions
might make it fail.
Nuclear deterrence cannot guarantee security. It
undermines it. The only possibility of security from nuclear attack
lies in the elimination of nuclear weapons as has already been
agreed to in the Non-Proliferation Treaty and reiterated in the
2000 Review Conference of that treaty. Ballistic missile defenses,
which increase instability, move the world in the wrong direction.
For its own security, the US should abandon its plans to deploy
ballistic missile defenses that would abrogate the Anti-Ballistic
Missile Treaty, and instead provide leadership in immediately
negotiating a Nuclear Weapons Convention leading to the phased
and verifiable elimination of all nuclear weapons, like the widely-acclaimed
enforceable global treaty banning chemical weapons.
is president of the Nuclear Age Peace Foundation. The author would
like to thank Commander Robert Green for his helpful suggestions
on this paper.