National missile defense: An indefensible system
Foreign Policy;
Washington; Winter 1999/2000; George Lewis; Lisbeth Gronlund; David Wright; Theodore Postol;
Abstract:
Lewis et al examine
the
Next summer, President Clinton
will decide whether the
The planned national missile
defense is more down-to-earth (literally and figuratively) than former
President Ronald Reagan's Strategic Defense Initiative (SDI), which was
intended to create a space-based shield against a massive Soviet nuclear
attack. In contrast, the current system would use ground-based interceptors to
destroy incoming warheads by colliding with them. indeed,
because it is intended to counter a more limited threat than the SDI system,
and because it would use existing rather than speculative technology, many
assume that, unlike SDI, the NMD system would work against the threat at hand.
Moreover, although many observers agree that SDI deployment might well have
aggravated the U.S.-Soviet anns
race, they assume that, with the end of the cold war and
However, neither assumption
about the security benefits and costs is warranted. Although it is now
technically feasible to "hit a bullet with a bullet" on the test
range, adversaries would be able to take straightforward steps to defeat this
system, not only preventing it from achieving the high levels of effectiveness
claimed for it, but also precluding any significant security benefits. Worse
still, deploying such a system would open a Pandora's box
of problems for the
A PLAN REVIVED
Although the SDI program that
began 10 years earlier was effectively dead when
In 1995, Congress passed
legislation mandating deployment of a limited national missile defense system
by 2003.
However, two events in the
summer of 1998 fundamentally altered the missile defense debate. First, in
July, the high-level, bipartisan Commission to Assess the Ballistic Missile
Threat to the
In January 1999, the
administration announced that it would make a deployment decision in the summer
of 2000 based on four criteria: the missile threat, the cost of the system, the
strategic and arms control implications of deployment, and the readiness of the
technology. Acknowledging that the system was being implemented faster than the
technology permitted, the administration pushed back the target deployment date
from 2003 to 2005.
Nonetheless, Republicans
reintroduced legislation requiring deployment as soon as possible. After
Current administration plans
call for a Deployment Readiness Review to be held in June 2000. This review
will be based largely on the results of three intercept tests, the first of
which took place in early October and successfully destroyed a mock warhead. If
the technology is deemed ready, the president will make a deployment decision,
taking into account the other three criteria.
It is possible that this
schedule could slip, but it cannot slip far if the 2005 deployment date is to
remain an option. According to the administration, to complete deployment by
2005, the
However, Russian public
statements have been uniformly critical of changing the treaty,
and several meetings between
SHOOT TO KILL
Although the
Existing or new early-warning
satellites would first detect the launch of an attacking missile. The NMD
system would then use different sensors to detect the missile
and any objects it releases, track these objects accurately enough to guide the
interceptors, and attempt to discriminate between the real warhead and decoys
or other false targets. These sensors include five existing early-warning
radars in
Using the information from these
sensors, the system would launch interceptors and guide them toward their
targets. As each interceptor nears its assigned target, it would release the
EKV, which would use infrared and visible light sensors to detect the target
and attempt to discriminate it from decoys or other false targets, and then use
thruster rockets to steer itself into the target. To increase the odds of
success, the system would likely fire several interceptors at each target. To
conserve interceptors, if time permits, the defense would use a shoot-
look-shoot strategy, in which one or more interceptors are initially fired at
the target. After observing the results of the intercept attempts, the system
would fire additional interceptors if necessary.
Under current plans, the NMD
system would be deployed in three phases. The first phase, referred to as
Capability 1 (C1 was originally designed to counter a threat composed of a
"few" (roughly five) warheads with either "simple" or no
countermeasures. However, the administration recently announced that this phase
would now involve the deployment of up to 100 interceptors and would be aimed
at countering "a few tens of warheads." This phase would upgrade the
early-warning radars and deploy one new radar. Because
The second phase, known as C2
and aimed at countering an attack by warheads with more complex
countermeasures, would deploy additional radars and enough interceptors to
bring the total to 100 or more, as well as the missile-tracking satellite
system, if it is ready for deployment. The C3 phase is intended to counter
threats consisting of "many, complex" warheads; it would deploy
additional radars as well as additional interceptors, including some at a
second site, bringing the total to 200 or more. Although the C3 system is the
current deployment goal, the system design explicitly permits further expansion
and upgrades beyond the C3 level by, for example, deploying additional
interceptors, increasing the number of interceptor sites, or deploying
space-based weapons. Moreover, a recent Pentagon study concluded that the NMD
system could be upgraded by integrating the hundreds of interceptors to be
deployed as part of the shipbased Navy Theater Wide
missile defense system. These interceptors would be plugged in to the sensor
structure of the NMD system.
How much will this system cost?
As of 1998, Pentagon estimates for deploying and operating an Alaska-based C1
and C2 system for 20 years were $21.5 and $28.3 billion, respectively. However,
there are no public cost estimates for the C3 system and, as for virtually all
major defense programs in such an early phase of development, the actual costs
are likely to be considerably higher.
WILL IT WORK?
Before assessing how well the NMD
system can achieve its stated objectives, it is useful to review some threats
that the system is not designed to counter.
First, ICBMS are not the
only-nor perhaps the earliest, most likely, or most effective-method available
to emerging missile states for delivering weapons of mass destruction to
Second, and more relevant to its
stated purpose, the NMD system cannot defend against ICBMS carrying biological
or chemical agents packaged in submunitions. To be
effective, biological and chemical agents must be dispersed across a large
area; for delivery by ICBM this is best accomplished by subdividing the agent
into dozens or hundreds of small submunitions that
would be released early in the missile's flight. Such submunitions
would also render the planned NMD System ineffective because there would be too
many targets to intercept.
While these are significant
limitations, the planned NMD could still make an important contribution to U.S.
security if it could protect against the remaining threat-a limited number of
nuclear weapons (which cannot be divided into large numbers of submunitions) delivered by ICBMS. How effective could a
Given today's technology, the
Many NMD proponents argue that
countermeasures are hard to develop and implement. In fact, the initial C1
deployment is aimed only at a threat that incorporates no effective
countermeasures. However, there are many countermeasures that are much easier
to build and deploy than either an ICBM or a nuclear warhead small enough to be
delivered on an ICBM-in other words, countermeasures that would clearly be
within the means of any emerging missile state that could build an ICBM. As
noted by the 1999 National Intelligence Estimate (NIE) on the ballistic missile
threat, which represents the consensus view of U.S. intelligence agencies, such
countries "probably would rely initially on readily available
technology" to develop countermeasures and could do so "by the time
they flight test their missiles." The NIE also states that "
The NMD system reportedly has a
design requirement of 95 percent effectiveness with 95 percent confidence
against a small-scale missile attack. Effectiveness is a measure of how well a
system works in the real world, which can only be determined through extensive
testing or use of the system. The confidence level describes how much trust the
user has in the effectiveness of the system, based on prior testing and use. In
each case, the stated "95 percent" goal is unrealistic. Even aside
from the countermeasure problem, an effectiveness of 95 percent is rarely-if
ever-achieved by a military weapons system, even after years of use. An
additional problem is that an NMD system must work the first time it is
actually used. If a nuclear ICBM attack occurs, there will be no opportunity to
learn on the job.
Because the real-world operating
environment could vary greatly depending on the types and combinations of
countermeasures the attacker uses, achieving a 95 percent confidence level
would require hundreds of tests conducted under different scenarios, costing
billions of additional dollars (the Pentagon reported that the first test cost
$ 100 million). If the tests do not adequately approximate the conditions under
which the system would operate, then even a large number of successfil
tests will provide little meaningful information about the system's operational
effectiveness. Worse, such tests could encourage a fake sense of confidence.
How does the Pentagon's planned
testing program measure up? The three tests that will take place before the
Deployment Readiness Review will not even begin to address the question of how
well the system would work in the real world. These trials will be limited to
demonstrating the basic functioning of the system in a relatively benign test
environment.
An additional 16 intercept tests
are planned before the target deployment date of 2005. However, it is doubtful
that these tests will attempt to assess the operational effectiveness of the
system against real-world countermeasures. To do so, the countermeasures used
would have to be designed by a truly independent group, and the NMD intercept
tests would have to be conducted without the operators knowing in advance what countermeasures
they would face. There is no indication that such a testing program is even
under consideration.
Given the extremely demanding
operational environment the NMD system will face, and given the need for it to
work the first time it is actually used, it is implausible that the system will
even approach the high levels of effectiveness claimed for it. Moreover, the
inadequate test program means that the
Supporters of national missile
defense envision three main missions, each of which would impose different
requirements on system effectiveness and the level of user confidence in that
effectiveness
Mission One: Preserve
Some NMD advocates argue that a
nuclear-missile-armed
This mission requires that
Underlying the concern over
nuclear blackmail is the notion that emerging missile states such as
Some NMD proponents argue that
deploying an NMD system would deter emerging missile states from developing or
deploying missiles capable of reaching the
Would this dynamic be different
in the case of ICBMs? As the 1999 National Intelligence Estimate concludes:
"Countries with emerging ICBM capabilities are likely to view their
relatively few ICBMs more as weapons of deterrence and coercive diplomacy than
as weapons of war. . . ." Thus, an emerging missile state is unlikely to
impose stringent requirements on the effectiveness of its ICBMs, because
deterrence would not require the certainty of a successful attack-only the real
possibility. (Emerging missile states are already willing to deploy relatively
unreliable missiles, as indicated by the very limited development and testing
programs identified by the Rumsfeld Commission.) The
deployment of countermeasures, either developed indigenously or purchased
abroad, would introduce enough uncertainty about the effectiveness of the
defense to accomplish this objective. In fact, rather than discouraging
proliferation, NMD deployment may have the opposite effect: Emerging missile
states might deploy more ICBMS to maintain their deterrent and coercive
potential by making it clear that they can penetrate the defense.
Finally, some NMD supporters,
pointing to the catastrophic damage that a single nuclear warhead explosion
could cause, argue that even a partially effective NMD system might prevent or
reduce damage in the event of an attack. In other words, when many thousands of
lives could be at stake, any defense is better than none.
Although it is true that even a
defense of unknown or low effectiveness could limit damage, this benefit would
likely be more than offset by the increased risk of an ICBM attack that an NMD
deployment may produce. The NMD system would provoke deep suspicion in
OPENING PANDORA'S SILO
Advocates of the NMD system
focus on its possible security benefits. Building such a system, however, will
also incur far-reaching security costs.
Despite the much-trumpeted end
of the cold war, the
If the proposed system is likely
to be ineffective, why should
Many influential military and
political leaders in
Many Russian officials find
unconvincing
Moreover, although the
It is for this reason that
deployment of the planned NMD System is fundamentally inconsistent with the
purpose of the ABm Treaty and will require much more
than the minor treaty changes the Clinton administration claims are needed. The
treaty, a centerpiece of the U.S.-Russian security relationship for over 25
years, provides two essential security guarantees: that a nationwide defense
would not be deployed and that an infrastructure that could be used to rapidly
deploy or expand such a nationwide defense would not be put in place. Not only
is the NMD system designed to provide nationwide coverage, but it would deploy
up to 10 new radars around the world, in addition to the five upgraded
early-warning radars, that would constitute the infrastructure for a much
larger defense. Thus, even if
How might
But this is unlikely to be
Moreover, Russian officials say
that they continue to see a link between offensive and defensive weapons. So
while Russia's nuclear arsenal is expected to decrease as a result of economic
constraints, a U.S. NMD deployment would likely block cuts to levels below
about 1,000 warheads, raising the possibility that the United States and Russia
would become locked into unnecessarily high levels of nuclear weapons for the
indefinite future.
Recent Chinese missile tests
have included countermeasures, which
The unavoidable deterioration of
relations with
Russian and Chinese responses to
a U.S. NMD deployment could have a significant ripple effect worldwide. For
example, a Chinese nuclear buildup could trigger buildups in
In the medium to long run, the
price of a national missile defense system deployed by the
WANT TO KNOW MORE?
The political story of how we
got to where we are today with national missile defense (NMD) can be traced in
more detail via several articles. In "Why the Right Lost the Missile
Defense Debate" (FOREIGN POLICY, Spring 1997), Joseph Cirincione
takes the story up through early 1997, analyzing the failure Of NMD advocates
to make it a major issue in the 1996 elections. He continues the narrative to
mid-1998 in "Rush to Failure" (Buletin of
the Atomic Scientists, May/June 1998). John Issacs'
"Missile Defense: It's Back" (Bulletin of the Atomic Scientists,
July/August 1999) describes the erosion and collapse of the
The problems countermeasures
pose for the proposed NMD system are discussed in George N. Lewis, Theodore A. Postol, and John Pike's "Why National Missile Defense
Won't Work" (Scientific American, August 1999). A more detailed discussion
of countermeasures can be found in Lewis and Postol's
"Future Challenges to Ballistic Missile Defenses" (IEEE Spectrum,
September 1997).
The best way to keep up with the
rapidly evolving debate over NMD is via the World Wide Web. A wide range of
fact sheets, photographs, and other materials on both national and theater
missile defenses are available on the Ballistic Missile Defense Organization's
Web site. A number of organizations opposed to, or skeptical Of NMD deployment
maintain Web sites that provide useful up-to-date information, documents, and
analyses, including: the Union of Concerned Scientists, the Federation of
American Scientists, the Council for a Livable World, the Non-Proliferation
Project of the Carnegie Endowment for International Peace, and the Coalition to
Reduce Nuclear Dangers. Also, see the missile defense and Anti-Ballistic
Missile Treaty section of the Web site of the Center for Arms Control, Energy,
and Environmental Studies of the Moscow Institute of Physics and Technology. An
assessment Of NMD that is generally supportive of the administration's approach
is Charles V. Pena and Barbara Conry's "National
Missile Defense: Examining the Options" (Policy Analysis, no. 337, March
16, 1999), available on the Cato Institute's Web site. The Heritage Foundation
Web site contains a number of reports that urge the immediate deployment of an
NMD System that goes well beyond the administration's plans, and emphasizes
sea-based and space-based NMD Systems.
The July 1998 Report of the
Commission to Assess the Ballistic Missile Threat to the United States (the
"Rumsfeld Report") played a crucial role in
enhancing the perceived ballistic missile threat. The 1999 National
Intelligence Estimate (Foreign Missile Developments and the Ballistic Missile
Threat to the United States Through 2015) by the National Intelligence Council
of the Central Intelligence Agency incorporates a number of the Rumsfeld Report's recommendations and also includes a
discussion of possible countermeasures that might be used by emerging missile
states. Unclassified versions of both these reports can be found on the
Federation of American Scientists Web site. See also, Richard L. Garwin's "The Rumsfeld
Report: What We Did" and Lisbeth Gronlund and David Wright's "The Rumsfeld
Report: What They Didn't Do" (Bulletin of the Atomic Scientists,
November/December 1998).
For links to these and other Web
sites, as well as a comprehensive index of related FOREIGN POLICY articles,
access www.foreignpolicy.com.
[Sidebar]
Balloons, Decoys, and Shrouds
The U.S. National Missile Defense (NMD) system would employ
interceptors that operate above the earth's atmosphere. In the vacuum Of space, there is no atmospheric drag, and both heavy
objects such as warheads and much lighter objects travel on identical ballistic
trajectories. This fact, and other characteristics of the
space environment, make possible a wide range of relatively simple but
effective countermeasures against the planned NMD system.
Such
countermeasures could be used alone or in many combinations. One often
discussed countermeasure is lightweight replica decoys. The attacker would
release large numbers of these objects along with the real warhead. Unless the
defensive system could determine which of the objects was the
actual target, it would have no choice but to fire at all of them, which
would quickly exhaust its supply of interceptors. Otherwise, it would risk
letting the warhead penetrate unchallenged. One way to make replica decoys
would be to use warhead-shaped balloons with a thin metal coating on their
outer surfaces to reflect radar waves. Such decoys might also contain heaters
to simulate the heat emission of the warhead and small weights to give spinning
and tumbling motions similar to that of the warhead.
Less discussed, but likely more effective, is a technique
known as anti-simulation. Rather than make all the decoys look like the
warhead, the attacker would disguise the warhead. For example, the attacker
could cover the warhead with irregularly shaped pieces of metallic foil to make
it look like a piece of missile debris. Alternatively, the warhead could be
released inside a metal-coated balloon, along with large numbers of similar,
but empty balloons. These balloons would differ slightly in size-and by varying
their shapes and surface coatings, they would have different equilibrium
temperatures. The defense would then face the nearly impossible task of telling
which of them was the real target
As an alternative to decoys, the warhead could be enclosed
within a thin metallic shroud that would be cooled with a small amount of
liquid nitrogen. This technique could reduce the range at which an infraredhoming kill vehicle could detect the warhead by a
factor of at least a thousand, in effect blinding the kill vehicle, and thus
defeating the defense.
[Sidebar]
Hitting Them Where It Works
by Theodore Postol
Whether or not one believes that the threat from emerging missile
states such as Iran, Iraq, or North Korea is serious enough to require
deployment of a national missile defense (NMD), it makes no sense for the
Clinton administration to advocate a defense concept that not only will fail to
work against these countries but also will provoke negative reactions from
Russia and China. But there is a way to provide a defense that would likely be
effective and also much less provocative to
A "boost-phase" missile defense-jointly built and operated by
This boost-phase missile defense would consist of very fast
interceptors placed in hardened underground silos or on offshore platforms at
distances of hundreds of kilometers from North Korean, Iranian, or Iraqi launch
sites. Silos might be deployed in the region near
When an ICBM is launched, it would be detected and tracked by
sensors placed on the ground, in unmanned airborne vehicles or aircraft, or on
satellites orbiting the earth. The missile defense system would then launch
boost-phase interceptors that would accelerate to 8 to 8.5 kilometers per
second in a little over a minute. Even if the launch of the interceptors were
delayed for a minute or more after the launch of an ICBM in order to establish
its trajectory, the interceptors could still destroy the ICBM while it was in
powered flight, causing its warhead to fall far short of its target.
Unlike the
A boost-phase defense system would face significant policy
obstacles. Getting countries such as
Perhaps
more serious, however, would be Chinese concerns that the boost-0 phase defense
could be turned into a mid-course defense capable of intercepting ICBMs
launched from anywhere in their country.
THEODORE
POSTOL is professor of science, technology, and national security policy at the
Massachusetts Institute of Technology.
GEORGE
LEWIS is associate director of the Security Studies Program at the
Massachusetts Institute of Technology (MIT).
LISBETH GRONLUND and DAVID WRIGHT are senior staff scientists at the Union of Concerned Scientists and research fellows at MIT's Security Studies Program.