NATIONAL MISSILE DEFENSE by Richard L. Garwin Philip D. Reed Senior Fellow for Science and Technology Council on Foreign Relations, New York and IBM Fellow Emeritus IBM Research Division P.O. Box 218 Yorktown Heights, NY 10598 Tel: (914) 945-2555 fax: (914) 945-4419 Email: RLG2 at watson.ibm.com Testimony to Senate Foreign Relations Committee May 4, 1999 Y123SFRC 050399SFRC 05/03/99 BRIEF BIOGRAPHY OF RICHARD L. GARWIN Richard L. Garwin was born in Cleveland, Ohio, in 1928. He is Philip D. Reed Senior Fellow for Science and Technology at the Council on Foreign Relations, New York, and Adjunct Professor of Physics at Columbia University. He has been a Professor of Public Policy at Harvard University. He joined IBM Corporation in 1952, and was until June 1993 IBM Fellow (now IBM Fellow Emeritus) at the Thomas J. Watson Research Center, Yorktown Heights, New York. He has made contributions in the design of nuclear weapons, in instruments and electronics for research in nuclear and low-temperature physics, in computer elements and systems, including superconducting devices, in communication systems, in the behavior of solid helium, in the detection of gravitational radiation, and in military technology. He is co-author of many books, among them Nuclear Weapons and World Politics (1977), Nuclear Power Issues and Choices (1977), Ballistic Missile Defense (1984), and Managing the Plutonium Surplus: Applications and Technical Options (1994). He has been awarded 42 U.S. patents and published many technical papers in physics, technology, and public policy. He was a member of the President's Science Advisory Committee 1962-65 and 1969-72, and of the Defense Science Board 1966-69. He is a Fellow of the American Physical Society and of the American Academy of Arts and Sciences; and a member of the National Academy of Sciences, the Institute of Medicine, the National Academy of Engineering, the Council on Foreign Relations, and the American Philosophical Society. He was awarded the 1983 Wright Prize for interdisciplinary scientific achievement, the 1988 AAAS Scientific Freedom and Responsibility Award, the 1991 Erice "Science for Peace" Prize, and from the U.S. Government the 1996 R.V. Jones Intelligence Award and the 1996 Enrico Fermi Award. He is a long-time member of Pugwash and has served on the Pugwash Council. He has been a member of the Council of the International Institute for Strategic Studies, and Chairman of the Panel on Public Affairs of the American Physical Society. His work for the government has included studies on antisubmarine warfare, new technologies in health care, sensor systems, military and civil aircraft, and satellite and strategic systems. He has chaired the Director's Advisory Committee of the Arms Control and Disarmament Agency, and has been a member of the Scientific Advisory Group to the Joint Strategic Target Planning Staff and in 1998 was on the 9-person "Rumsfeld" Commission to Assess the Ballistic Missile Threat to the United States. INTRODUCTION. This Committee knows well the characteristics of the threat facing the United States, which were reviewed in part by the Rumsfeld Commission in 1998. As one of the nine members of that Commission, I concurred in the unanimous report published July 15, 1998, which assessed the ballistic missile threat to the United States. In brief, we considered both nuclear weapons and biological weapon payloads as strategic threats. We noted the thousands of warheads still available and deliverable by long-range missile from Russia; the 10 to 20 ICBMs available to China, armed with nuclear weapons; and the possibility that any of three additional nations with which the United States is not on friendly terms-- North Korea, Iran, or Iraq-- could within five years of a decision to do so have an ICBM that could strike some of the 50 United States. This judgment was based on the assumption of a concerted program, well funded and given priority, with due attention to denial and deception, as it has been increasingly practiced by countries that wish to hide the scope of their activities from U.S. intelligence. Of course, other nations have much greater capabilities than these three; for instance, Britain or France could deliver hundreds of nuclear warheads against the United States, but we have no fear that they would do so. With its space launch vehicle, India could also deliver a nuclear weapon, and Israel has apparently quite a few nuclear or thermonuclear weapons, but they are also not classed as threats to the United States. The Rumsfeld Commission further noted that short-range ballistic missiles based on ships and armed with nuclear or biological payloads would constitute a threat more readily available than ICBMs to North Korea, Iran, or Iraq; and that ship-launched cruise missiles available commercially would add to that threat. The Rumsfeld Commission did not consider as a group the vulnerability of the U.S. to BW attack from ships off shore, from cars or trucks disseminating BW, from unmanned helicopter crop dusters, or from smuggled nuclear weapons or nuclear weapons detonated in a U.S. harbor while still in a shipping container on a cargo ship; but these capabilities are more easily acquired and more reliable than are ICBMs. In January 1999, Secretary of Defense William Cohen announced that a decision to deploy a National Missile Defense would be considered in summer of the year 2000, based on the existence of the threat and the technological readiness of an NMD system to counter it. He modified the Administration's "3 + 3" program which had promised that within three years (by the year 2000) an NMD would be developed capable of deployment within the following three years (2003), so that deployment would now take place in 2005 in case of a favorable decision in summer, 2000. The "3 + 3" program had intended that development would continue in the case that deployment was not authorized, so that year by year what could be deployed within three years of a decision to do so would be increasingly capable. A decision to deploy would need to freeze the technology in order to build a system within three (or five years). NATIONAL MISSILE DEFENSE Rather than recount my view of the history of the NMD program, let me just give a judgment on the program as it is now defined. It is contemplated that to counter a relatively few warheads, 75 ground-based interceptors (GBI) would be built, and some 20 deployed. The system specifications require extremely high confidence that not a single warhead penetrate to U.S. soil. In my opinion, no system thus far proposed could achieve such confidence, even against cooperating warheads. Nevertheless, the problem with the NMD system is not simply that it could not fulfill its stated requirement, but that it would have essentially no capability against a long-range missile system deployed by North Korea, Iraq, or Iran to strike the United States with biological weapons or with nuclear weapons. I make this judgment on the basis of a substantial knowledge of the NMD system as it is proposed, of previous efforts to develop a system of missile defense of the nation (and of Theater Missile Defense), and of a close look over the decades at countermeasures that are feasible to defeat missile defenses. The problem is a simple one. Begin, for instance, with North Korea. If North Korea wished to maximize its capability to cause death or damage in the United States by the launch of a first-generation ICBM, it would not use a so-called unitary payload of BW, which would perhaps deliver tens or hundreds of kilograms of anthrax or other infectious or even contagious microbe on some city. The result would be a very narrow plume carried by the breeze, which would kill most of the people in its path, but would leave those outside the plume untouched, except in the case of extremely contagious germs such as smallpox. Rather, a country could make much better use of a limited payload capacity by packaging the BW agent in the form of individual bomblets that would weigh a kilogram or so, and that would be released by the missile just as soon as it had reached its full velocity on ascent. That is, just after boost phase. The bomblets would fall separately through the arc of the trajectory to their target, and would reenter the atmosphere without incident, having been provided with a thin ablative reentry shield. After the heat of reentry, the shield could be shed, as was the case with the reentry of the film buckets of the first U.S. strategic reconnaissance system-- CORONA, and the bomblets would fall to Earth, where a thoroughly tested device would expel the BW agent. This could be a mild explosive burster charge or some other mechanism. Given this approach to increased military effectiveness, the planned National Missile Defense system has no possibility of making an intercept so early in the trajectory. If the adversary has a nuclear weapon that can be delivered by ICBM, it can evidently not break it up into 1-kg bomblets A first-generation nuclear weapon would probably have a yield of 10 to 20 kilotons (like those U.S. nuclear weapons that devastated Hiroshima and Nagasaki in August 1945). So the NMD system would have a chance to observe the flight-- first the DSP satellites would see the booster flame (as in the case of BW as well); then the upgraded early warning radars would see the warhead in mid-course, together with whatever simple countermeasures might have been used (and the spent final-stage fuel tank); and X-band radars would perhaps help to discriminate the real warhead from decoys or junk. A sufficient number of ground-based interceptors would be launched to obtain (in principle) the desired damage expectancy by their hit-to-kill intercept against the incoming nuclear warhead. If the interceptors were based at Grand Forks, ND, there would in general not be time to observe the success of an intercept before launching a second GBI. If the interceptors were based in Alaska, a launch from North Korea would provide some time for such shoot-look-shoot. To my mind, there is no significant difference between the protection of the country offered by interceptors based in Alaska compared with those based in North Dakota. Protection would be negligible in either case. The reason is that a simple countermeasure would defeat the system as planned. Depending on the preferences of the adversary, this countermeasure could take the form of a large enclosing balloon around the reentry vehicle that contains the nuclear warhead. Immediately after achieving full velocity, the warhead would separate from the final stage of the missile, and a simple gas generator containing a few grams of material (like that in every airbag in modern automobiles) would gently inflate a metallized plastic balloon that had been crumpled down onto the warhead by a household vacuum cleaner exhausting most of the air. Or inflation could be done simply by compressed gas. A warhead that might be five feet long could be enclosed in a balloon 30 ft in diameter, so that it would be perfectly well visible to the radars and to the hit-to-kill homing vehicle of the ground-based interceptor. But the homing vehicle which would strike the balloon (if all goes according to plan) would have very little probability of striking the warhead contained within. A thin aluminum coat on the plastic is opaque to radar and also to infrared invisible light, which are the means by which the homing kill vehicle (HKV) is expected to strike its target. Depending upon the characteristics of an isolated target, such intercept might take place in principle with an accuracy of one foot or less, providing high probability of kill (if the equipment and software is reliable-- which it is not yet). But with the aimpoint hidden, the chance of striking the warhead would be tiny, considering its small size compared with the enclosing balloon. One might imagine that the collision of the warhead with the balloon would generate sufficient gas from the very high velocity impact of the thin balloon on the interceptor as it is going by, to blow away most of the remainder of the balloon and thus to expose the warhead, bare, to the other interceptors that may follow. This is a possibility, and the United States would no doubt wish to test this prospect (following the best analysis we can do), but unfortunately for the effectiveness of the defense, this approach is readily defeated by the offense, without testing in space. The offense could have several such balloons shrunk down one over the other, and independently expanded when the outermost balloon is blown away. It is not necessary to define the countermeasures that an adversary nation might use, but only to understand those that might work. They could choose among several others. Another simple countermeasure that might have greater appeal to some, would be to use not a large balloon but a small one, not much bigger than the warhead itself. Then additional small balloons would serve as decoys, if the HKV could not tell them apart by means of its multi-spectral sensor. More than 30 years ago, the Strategic Military Panel of the President's Science Advisory Committee, of which I was a member, observed that an adversary would no doubt use "anti-simulation" rather than rely strictly on a decoy's simulating the characteristics of the warhead. Thus, if the warhead were to be coasting bare through space, perhaps spinning in a stable fashion, decoys in order to be credible would need to be pretty much the same size and have the same spin. However, with anti-simulation, the idea is that the warhead would be modified or clothed, so as to make it easier to simulate. The warhead would simulate a cheap decoy, rather than the decoys being required to simulate an expensive and precise warhead. An easy way to begin anti-simulation is to put the warhead in a small lumpy balloon. This would take care of the radar simulation quite well. It might be better also to have a warhead that is not spun up, as was the case with warheads of other countries for a long time. Spinning the warhead improves the reentry accuracy, because a displacement of the external reentry vehicle from the center of mass of the warhead otherwise leads to substantial error. But the first-generation ICBMs are so inaccurate that this will not be a significant impairment of their accuracy. In any case, it is entirely possible for a warhead to be spun up just as it begins to reenter and after all possibility of intercept by the NMD system has passed. When to spin is simply a design choice, and if spinup before reentry helps to penetrate an NMD system, it can readily be done. The warhead itself has substantial mass (perhaps 500-1000 lbs.) and so does not cool appreciably in its passage through space. Thin empty balloons, on the other hand, have no such heat capacity. Nevertheless, it takes less than a pound of lithium battery within such a balloon to supply as much heat radiation to the interior of the balloon as the warhead itself would provide, if the warhead were shrouded in commercially available multi-layer insulation, widely used in refrigerators, transport of liquid nitrogen, and in space applications. While the NMD o would have no capability against bomblets carrying BW dispersed on ascent, or against a nuclear weapon in a large enclosing balloon, o nor could it discriminate a warhead in a small balloon, properly done, from perhaps 10 empty small balloons, o would neither see nor be able to intercept short-range ballistic missile launched from ships near U.S. shores, o would neither see nor be able to intercept short-range cruise missiles launched from ships near U.S. shores, it is possible to protect the United States against the attack by long-range ballistic missiles. The beginning of protection lies with deterrence of such attack, and even deterrence of building such a capability. Deterrence against use comes from the certainty of nuclear response to nuclear attack against the United States, and such a response would be overwhelming. Deterrence against building such a capability derives from its lack of utility, since its use is likely to be deterred by the threat of retaliation. Furthermore, a nation deploying an ICBM system to threaten the United States would surely feel vulnerable to preemptive attack, if the United States learned where the missiles were based. Nevertheless, a limited ICBM capability might be built for political reasons, despite the insecurity that it would pose. It is possible to intercept the ICBM in boost-phase-- while the main rocket engines are still burning, so that the task of a homing interceptor is far simpler than that posed to the ground-based interceptor that must see a cool warhead at great distances in space. But such a system has essentially nothing in common with the National Missile Defense that is proposed. It would use the existing DSP satellites to determine the time and rough direction for launch of a ground or sea-based interceptor. But the fundamental characteristic of that interceptor is that it should reach ICBM velocity of 7 km/s and should do it in about 100 s rather than the 250 s of a typical ICBM. Under these circumstances, there is a vast area in which the interceptor could be deployed and still make the intercept in boost phase. Specifically, against North Korea, such interceptors could be deployed at a joint U.S.-Russian test range south of Vladivostok (if Russia wished to cooperate with the United States in this regard) or, in principle, from military cargo ships in a vast range of ocean area. Because such sea-based capabilities might be useful for defense of Japan, for instance, against theater-range missiles launched from North Korea, and because there is already in the September 26, 1997 "Agreement on Confidence-building Measures Related to Systems to Counter Ballistic Missiles Other Than Strategic Ballistic Missiles" (signed but unratified) a provision by which the Parties to the ABM Treaty of 1972 accept the deployment of ballistic missile defenses that do not "pose a realistic threat to the strategic nuclear force of another Party", it is possible that Russia, Belarus, Kazakhstan, and Ukraine would agree specifically to a few large interceptors based on ships to carry out boost-phase intercept of missiles launched from North Korea-- which is, after all, not a Party to the ABM Treaty. CONCLUSION. o We should not deploy the proposed National Missile Defense unless it is proved capable of handling the countermeasures that can realistically be employed by the potential adversary. o The evaluation of NMD should start from scratch with the use of ground-based or ship-based interceptors that will destroy the offensive missiles in boost phase-- before they can release bomblets or separate a warhead that could then provide itself with an enclosing balloon. o There is no reason to abandon the protection of the ABM Treaty, that constrains Russian defenses and thus allows the United States to deter Russia with modest numbers of nuclear weapons, thus facilitating further great reductions in the only nuclear threat to the survival of the United States.