GUEST PERSPECTIVE (Inside Missile Defense, July 12, 2000)
   (Posted with the permission of Inside Missile Defense)

Boost-Phase Intercept -- Not If, But When

Richard L. Garwin, July 2000

     While the National Missile Defense interceptors
confront very limited countermeasures in flight tests, the
mid-course U.S. NMD system under development today would
fail catastrophically if North Korea launched a few
primitive intercontinental ballistic missiles fitted with
penetration aids that are far easier to make than the ICBMs
themselves.
     In contrast, no biological warfare or nuclear payload
on a "rogue nation" ICBM -- the stated reason for building
the NMD system -- will reach the United States if the
missile is intercepted before it gets to full speed, while
its rocket engine is still firing. Intercepting a North
Korean ICBM could be achieved through use of existing
satellites and the deployment of large interceptors based as
much as 1,000 kilometers from North Korea -- on U.S.
military cargo ships or on Russian territory.
     I have long proposed such a ground- or sea-based
boost-phase intercept capability to handle potential ICBM
launches from North Korea, Iraq or Iran. This system, which
would be operable only in specific locations, would also
require a simple protocol modification of the Anti-Ballistic
Missile Treaty.
     In July 1998, the Rumsfeld Commission, of which I was a
member, judged that rogue nations or

"states of concern" could build a few unreliable, inaccurate
intercontinental ballistic missiles within five years -- if
they began a concerted, well-financed program immediately
and received substantial foreign technological help.
Further, the United States might not know for most of that
five-year period that such an acquisition program was under
way.
     The commission also found that any of these states
could threaten the United States more readily and more
cheaply by developing or acquiring short-range ballistic or
cruise missiles that could be launched from cargo ships near
U.S. shores. These would have better accuracy and greater
payload than a primitive ICBM.
     We also warned that these states would increase the
strategic effectiveness of any biological warfare payload,
like anthrax, by loading it into hundreds of bomblets rather
than a single, massive warhead. Further, we were critical of
the intelligence community for basing its threat assessments
largely on what was actually observed, without serious
consideration of what might be going on under cover of
denial and deception -- D&D.
     Our report has been misused by those who support the
ongoing NMD program. We judged only the capability of these
states to mount such an ICBM program; the feasibility of a
defense against any of these threats was totally outside our
charter. U.S. National Intelligence Estimates (NIE) since
mid- 1998 have recognized the impact of D&D, and they are
designed to judge the actual status of ICBM programs rather
than their potential.
     Since 1991, I have warned that the proposed midcourse,
hit-to-kill defensive concepts -- first the Global
Protection Against Limited Strikes (GPALS) system and later
the NMD system -- would not counter the anthrax threat even
of early ICBMs, because any state capable of building ICBMs
could far more readily outfit them with anthrax bomblets
released on ascent--increasing its effectiveness over a
larger, single anthrax warhead. Similarly, a nuclear warhead
from these states would penetrate the defense by the use of
multiple empty balloons, together with an "anti-simulation"
balloon around the real warhead.
     In April, with 10 other independent physicists, I
published "Countermeasures", a 175-page report providing
details culled from open sources on anthrax bomblets,
anti-simulation and decoy balloons and a warhead shroud
cooled by liquid nitrogen -- all designed to defeat the
hit-to-kill NMD mid- course interceptor.
     A single ICBM that distributes 50 or 100 anthrax-filled
bomblets as soon as it gets up to speed will ensure that few
or none of them can be intercepted by the proposed NMD
system. A missile with a nuclear warhead would launch dozens
of inflated, aluminized mylar balloons, with the warhead
itself inside a similar balloon; neither the radars nor the
infrared sensors on a U.S. interceptor could distinguish one
balloon from another. And a cooled shroud would render the
warhead invisible to a homing kill vehicle, which could
therefore not collide with it.
     In a June 20 press conference, Under Secretary of
Defense for Acquisition, Technology and Logistics Jacques
Gansler acknowledged that the United States would have to
launch interceptors at every multiple warhead or bomblet.
Some excuse the NMD system, because it is "not designed to
defend against bomblets." Ballistic Missile Defense
Organization and Office of the Secretary of Defense
officials characterize those who say the NMD system as
incapable of dealing with countermeasures as "naãve" and
"unaware" of intelligence information on the threat, or of
the tools and technologies available to the NMD program to
counter these penetration aids. Neither of these adjectives
fits me; the Rumsfeld Commission, by law and in fact, had
access to all intelligence information available to the U.S.
government.
     BMDO claims that North Korea, for example, could not
actually deploy anthrax bomblets and anti-simulation
balloons for several years, when unstated
counter-countermeasure technologies are supposed to be able
to deal with them. I say two questions must be asked: First,
when will North Korea be able to deploy anthrax bomblets --
assuming it already has anthrax in warheads weighing 500
kilograms or more -- as well as decoys and a nuclear warhead
in an anti-simulation balloon, assuming the country has a
nuclear warhead? Second, when will the United States have a
deployed capability to deal effectively with these
penetration aids?
     The first can be answered not through highly sensitive
intelligence gathering but by two approaches advocated by
the Rumsfeld Commission: THINKINT and TRYINT. This is
what the authors of the Countermeasures volume tried to do
in some detail. Whether these pen-aids are effective is the
second question, which we addressed by using general
physical arguments, assuming the best possible performance
of radars, infrared seekers and the like.
     According to TRW and BMDO documents, the mid-course NMD
system under development today would rely for discrimination
purposes on mission data loads based on current
intelligence.  Some argue that the United States will know
more about an adversarys pen-aids than it does itself.
This might be true if pen-aids were tested in flight, but
those described in the Countermeasures report could be
thoroughly tested on the ground. An adversary would be
foolish to test them in flight.
     None of these problems applies if intercept can occur
before the ICBM reaches a speed that would carry its payload
to the United States. If an ICBM can be struck in its boost
phase by an interceptor traveling at 10 kilometers per
second, it will be destroyed by an impact of energy
corresponding to half a ton of explosive. And if the
missiles burn time is cut short by as little as 10 seconds,
the payload will fall short by 5,000 kilometers -- well shy
of the United States or Canada.
     The system I have advocated since 1991 would use the
Defense Support Program satellites that detected every
ballistic missile launch during the Gulf War -- even SCUD
missile launches in the 300- kilometer range -- and feature
NMD-class 15-ton interceptors based within about 1,000 km of
prospective ICBM launch sites. North Korea -- a state the
size of Mississippi -- would be an ideal target for such an
incremental deployment system because it abuts Russian
territory south of Vladivostok and is near vast regions of
ocean available for sea-based interceptors. The interceptors
would be deployed at a joint U.S.-Russian anti-ballistic
missile site or on U.S. military cargo ships hundreds of
kilometers from North Korea.
     I assume that interceptors are launched within 100
seconds of ignition of the ICBM, for which I assume a
250-second burn time; considerably longer burns are expected
for such a liquid-fueled early ICBM. A ground-based
interceptor (GBI), which could also be based at sea, could
reach 8 kilometers per second within 100 seconds -- an
average acceleration of 8 Gs, or gravity forces -- and could
easily detect the ICBMs enormous booster flame as soon as
the GBI leaves the atmosphere. To the GBIs seeker, the
booster rocket would appear 1,600 times brighter at 1,000
kilometers that it would to DSP satellites at 40,000 km.
Further, an uncooled seeker that is sensitive in the visible
spectrum is ideal for the initial stage of homing.
     As the GBI approaches the booster flame, the homing
point must shift from the brightest portion of the flame to
the nearby missile body. A thermal infrared seeker of very
limited capability should suffice to see the booster hard
body and complete the intercept; this seeker may or may not
be cooled.
     Such a deployment is not compatible with the letter of
the ABM Treaty, but a simple protocol added to it would
accommodate this system. This addendum, for example, need
only state that the parties to the treaty agree on further
deployments of ABM systems that do not use ABM radars and
rely instead on boost-phase interceptors at jointly operated
sites, or of agreed design and operable only in areas such
as the Japan Basin. Notably, Russian President Vladimir
Putin recently spoke of Russian willingness to help allay
U.S. concerns about North Korean ICBMs by cooperating on a
system designed to intercept such launches in their boost
phase.  We should be able to take yes for an answer.
     The system I propose would not use the Upgraded Early
Warning Radars, X-band radars, Space- Based Infrared Systems
Low component, or other aspects of the NMD system. It might
not satisfy some who would not support the NMD if it worked
perfectly against rogue states but had no capability against
Russia or China, nor those who support boost-phase intercept
only as an adjunct to a layered system.
     We should defer a decision to deploy the NMD system
until there is credible and demonstrated evidence that it
can deal with the pen-aids that I have described. We should
slow the hectic pace of development, and transfer funds and
attention to analysis and demonstration of boost-phase
intercept capabilities based on DSP and a large NMD-class
interceptor. Small research contracts should be let to allow
companies to demonstrate, within months, low-resolution
visible-band seekers that will operate during 30 G
interceptor boost. Also, existing non-ABM radars should be
analyzed for their utility in detecting ICBMs at altitudes
of 50 km. or more.
     I believe this kind of BPI system could be available
sooner than the U.S. NMD system now under development. More
importantly, it has a good chance of working against the
missiles that can be fired at us from emerging missile
powers.

Richard L. Garwin is a fellow emeritus at IBM's Thomas J.
Watson Research Center in Yorktown Heights, NY, and the
Philip D. Reed Senior Fellow for Science and Technology at
the Council on Foreign Relations, New York. He has been a
consultant to the U.S. government on nuclear weapons and
national security since 1950. His writings on ballistic
missile defense, arms control and other national security
issues are available at the Federation of American
Scientists web site (www.fas.org/rlg). The April 11, 2000,
"Countermeasures" UCS-MIT report cited above is available at
the Union of Concerned Scientists web site (www.ucsusa.org),
in hard copy and on CD-ROM.