Commentary Magazine


“Star Wars” & the Scientists

To the Editor:

I want to commend Robert Jastrow for his article, “The War Against ‘Star Wars’” [December 1984]. His arguments are painfully correct in their direction, and, as a result, Mr. Jastrow has been attacked in a very sharp manner.

His detractors, some of whom are publicly well-known, have raised and will continue to raise the argument that Mr. Jastrow, lacking clearance, is inadequately informed. It is important to realize that by abstaining from getting clearance, Mr. Jastrow has retained his freedom of speech. This privilege is one of his main weapons, one which is not available to those of us who have spent years working on the problem of defensive weapons before supporting a major program for their development.

It is worth noting that Hans A. Bethe, one of the outspoken opponents of the Strategic Defense Initiative (SDI), conceded during a classified discussion in February 1983 that the relevant arguments in physics supported the Livermore Laboratory strategic-defense position. Shortly thereafter, however, Mr. Bethe changed his mind—not because the scientific issues had changed, but on the basis of his ideas about proper politics and military strategy. Mr. Bethe has waited almost two years before scheduling another (forthcoming) visit to review the Livermore strategic-defense work, although he has felt free to attack it on the basis of his outdated knowledge in the interim.

The position taken, by Hans A. Bethe, Victor F. Weisskopf, and many other “concerned” scientists is strongly reminiscent of the hydrogen-bomb controversy which raged more than three decades ago. The argument then was that the project was not scientifically feasible, and if it were successful, the result would be too terrible to bear. Furthermore, the argument went on, if the United States did not attempt the project, probably the Soviets would also forbear.

As it turned out—according to Andrei Sakharov’s biographical statement in Sakharov Speaks (Knopf, 1974)—before the hydrogen-bomb debate began in the United States, the Soviet hydrogen-bomb project was already under way. Only months separated the successful tests of a fusion weapon by the United States and the Soviet Union. Yet the United States had the advantage that it had been physically untouched by World War II, while the Soviets had suffered terrible damage.

The consequences of a Soviet success on this project coupled with American non-participation would have speeded up the kind of behavior today being demonstrated by the Soviets on the basis of their military superiority. However, the consequences of the Soviets’ successful development of protective defenses and our failure to do so are incomparably greater. There is much evidence—evidence that in comparison with that available in the earlier controversy should be called overwhelming—that the Soviets are hard and successfully at work on strategic defense. President Reagan’s Strategic Defense Initiative would be more appropriately named if it were called the Strategic Defense Response. Yet Mr. Weisskopf, present for President Reagan’s original speech requesting the cooperation of the scientific community in this effort, appeared to disapprove before the President even had time to develop his point.

Returning to Mr. Jastrow’s article and. his purported lack of scientific information, I would end with a question. Which better represents the method of scientific inquiry: limited, careful arguments that include all of the pertinent perspectives, or dogged support of narrow convictions based on superficial assessments?

I appreciate Mr. Jastrow’s courage in attempting to bring reason and common sense to this vital discussion.

Edward Teller
The Hoover Institution
Stanford, California

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To the Editor:

I read Robert Jastrow’s article with great interest. It has always been a matter of surprise to me that some members of the scientific community have been critical of the technical soundness of our strategic-defense efforts, when it is clear from my knowledge of the research program that the technical promise is great. Indeed, rapid progress has already been realized in some of the most critical areas. In addition, prospects for countering future missile defenses or overwhelming such defenses seem less and less likely as we come to understand better the potential of the new defensive technologies.

James A. Abrahamson
Lieutenant General, USAF
Director, Strategic Defense Initiative Organization
Department of Defense
Washington, D.C.

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To the Editor:

“The War Against ‘Star Wars’” by Robert Jastrow was as excellent an article on this major public-policy question as it was overdue. Those of us constrained by the restrictions of government security clearance often despair of responding effectively in public forums to critics of the Strategic Defense Initiative. Government classification rules perversely permit all manner of nonsensical “straw men” to be put forward and then kicked apart by those holding clearance and exploiting the prestige of being “in the know,” while strictly forbidding countervailing arguments containing compelling technical material to be aired publicly. Mr. Jastrow’s article demonstrated that a response to SDI critics on a more fundamental level is not only feasible but can be telling, for these critics unblushingly impeach themselves at levels of logical consistency recognizable by a perceptive undergraduate.

A notable example of this gambit of kicking apart a straw man of one’s own manufacture, and one with which I happen to be particularly familiar, involves X-ray laser technology, which has been singled out by the Union of Concerned Scientists (UCS) as “the leading candidate” among pop-up defensive systems, and thus has been extensively assailed by them in public. The straw man in this case consists of the assertion that X-ray laser platforms having carefully chosen limitations, when popped up from carefully selected sea- or land-basing points in time of defensive need, cannot engage even present-generation ICBM’s, let alone ICBM’s of some future era employing hypothetical “fast-burn” boosters, due to limb-of-the-earth constraints on X-ray-laser-beam propagation from the platform to the booster targets.

In fact, it has been explained on many occasions, to a variety of government forums all over the country, why and how reasonably-sited, technologically-accessible, popped-up X-ray lasers can plausibly engage even fast-burn boosters, and at cost-exchange ratios which strongly favor the defense. Some of these occasions have involved face-to-face discussions with leading strategic-defense critics, none of whom has contested the technical points being made. Nonetheless, the public debate continues to be saturated with pessimistic assertions by these critics concerning this point which, to put it charitably, are disingenuous.

The stunningly effective supporting barrages laid down by sympathetic sectors of the news media amplify the efforts of SDI critics completely out of proportion to their minuscule numbers, ludicrously inflating them into “virtually all knowledgeable scientists”; even the Wizard of Oz was less flagrant in his mummery, more modest in his pretensions. This hyperinflation is the more remarkable as anti-strategic-defense arguments have fared uniformly poorly in technical debate in the classified surroundings required by government regulations. In spite of having failed to make their anti-SDI case to their well-informed colleagues in technical discourse, these critics continue to advocate their rejected positions to the public in impassioned terms, immune from the criticism of their technical peers.

Mr. Jastrow has performed a real service to the thoughtful public by documenting how sloppily this tiny group of scientists compound their nostrums, and with what generous dollops of bias. Focusing on this basic point, his article made devastatingly clear that these individuals, capable scientists though they may be, do not merit the political confidence of their fellow citizens.

Lowell Wood
Lawrence Livermore National Laboratory
Livermore, California

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To the Editor:

Robert Jastrow has done it again. He seems to be the greatest single asset we have in making a strategic-defense system an eventual reality. . . . Ever since I took part in a debate on strategic issues sponsored by the Union of Concerned Scientists, I have realized the irrational fear of ABM systems among many intellectuals. People who would acquiesce in an actual U.S. surrender to the USSR to obviate the risk of nuclear war, but would not be willing to spend tens of billions of dollars to banish its possibility forever, show where their objectives really lie. . . .

George Fishman
University of Illinois
Champaign, Illinois

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To the Editor:

Mr. Reagan’s proposed Strategic Defense Initiative raises issues of the utmost gravity. We are astonished that COMMENTARY would present a brief for SDI in the guise of an uninformed attack against the report prepared by us under the auspices of the Union of Concerned Scientists, The Fallacy of Star Wars (Vintage, 1984). Robert Jastrow’s “The War Against ‘Star Wars’” takes issue with our criticisms of SDI by pretending that the entire enterprise stands or falls on a precise calculation of how many laser satellites would be required by the defense. There are some honest disagreements among knowledgeable experts that are central to the SDI debate which we wish to bring to your readers’ attention, but this is not one of them.

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In his “Star Wars” speech, Mr. Reagan proposed to defend the population of the United States against Soviet nuclear-armed missiles, and thereby to replace deterrence as the bedrock of our national security. As recently as December 23, 1984, the President and his Secretary of Defense restated this objective in order to proscribe heresies within their administration: SDI would not be bargained away, they asserted, or be devoted to the lesser goal of merely defending American missile silos.

A ballistic-missile defense (BMD) of cities is inconceivable unless the great majority of Soviet ICBM’s could be destroyed while their fragile booster engines are still burning brightly. Missiles that survive this “boost phase” would pose a much more formidable threat to any defense because they would release a large number of elusive and far less vulnerable warheads immersed in a vast swarm of decoys and other “penetration aids.” The subsequent defensive layers could not, it is widely acknowledged, cope with such a prodigious “threat cloud.” The fact that the earth is round requires an attack on Soviet boosters to be launched from space.

We examined all credible proposals for boost-phase defense. (While infrared and laser homing projectiles are promising interceptors for mid-course and terminal defense, they are implausible boost-phase weapons because of their low speed.) Orbiting defenses suffer from a fatal flaw: they would rely on delicate precision instruments which would be exquisitely vulnerable to attack. We share this conclusion with Edward Teller, an ardent SDI advocate, who has said that “lasers in space won’t fill the bill—they must be deployed in great numbers at terrible cost and could be destroyed in advance of an attack.” As we shall see, Mr. Jastrow’s own argument leads to the conclusion that countering new Soviet ICBM deployments with orbiting lasers would be ludicrously expensive.

These pitfalls could be averted if the defensive weapons were “popped-up” into space on warning of attack. But this would pose insuperable time constraints: the defensive weapon must rise to a height of at least 650 miles before the enemy booster completes firing, feasible with current slow-burning Soviet missiles, but hardly practical against a Soviet equivalent of the much faster MX. Furthermore, the Soviets could readily develop boosters that finish burning too soon for any pop-up scheme to work.1 Claims that the Soviets would find it difficult to develop such “fast-burn” boosters should be laid to rest by noting that our SPRINT missile, which operated as a BMD interceptor in 1974, already demonstrated this technology.

In sum, no technical scheme exists for a comprehensive strategic defense free of fundamental conceptual flaws. As former Secretary of Defense James Schlesinger has said, “In our lifetime and that of our children, cities will be protected by the forbearance of those on the other side, or through effective deterrence.” Nor is there any basis for Mr. Jastrow’s assertion that the reports of the “blue-ribbon panels,” appointed at the President’s request, are “as different” from our report “as day is from night.” The technical [Fletcher] panel’s summary emphasizes that “survivability of the system components is a critical issue whose resolution requires a combination of technologies and tactics that remain to be worked out.” Major General John C. Too may, the panel’s Deputy Chairman, has said that the panel tended to be “pessimistic whether these technical objectives could be realized but felt that, on balance, the research and engineering was well worth doing,” and that the difference between the panel’s qualified assessment and its recommendation is “like the difference between the horse you bet on and the sentimental favorite.”2

Not only is there no technical scheme, there is not even the vaguest outline for a political scenario that might propel us toward a defense-dominated world. That political factors are essential was recognized in the Fletcher report, which stated that the effectiveness of the defense would depend not only on technology, but also on the degree to which Soviet offensive forces could be constrained. Moreover, the Hoffman panel, which considered the strategic implications of SDI for the President, noted that the past behavior of the Soviets “suggests that they would be more likely to respond with a continuing build-up of their long-range offensive forces.”

Hence our disagreement with knowledgeable and candid supporters of SDI is one of risk assessment. They are gambling on the President’s “sentimental favorite,” in the hope that unforeseen technical advances might transform the prospects for strategic defense, and are not as troubled as we are by the risks that the pursuit of SDI would entail. Our studies persuaded us that all the envisaged BMD schemes are ruinously expensive, and could not protect the United States from utter destruction because they could be readily overwhelmed or outfoxed at much less cost. We shall also explain why the very attempt to proceed toward a comprehensive missile defense will provoke a massive escalation of the competition in offensive nuclear weapons, and increase the likelihood of nuclear war.

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Why should a thrust toward strategic defense have any risks beyond galloping budget deficits? What is the harm in trying? This has been answered by the Hoffman panel: defenses that could withstand a small attack, but would collapse under a large onslaught, are highly provocative. In the early stages of BMD deployment we would have just such a defense, as well as vulnerable land-based missiles. This would have two grave hazards. First, the Soviets would fear that if the U.S. were to attack preemptively our defense could cope with their surviving missiles; they would also know that our defense could, at most, provide poor protection of our vulnerable missiles against a Soviet first strike. This would greatly enhance their incentive to attack preemptively in a serious crisis.

Second, Soviet leaders have asserted that they would avert this predicament by enlarging their offensive capabilities. This build-up would emphasize submarine-based cruise missiles, which underfly space defenses and provide little warning; ICBM’s equipped with countermeasures against U.S. defense; and anti-satellite weapons to attack our BMD space platforms. Painfully aware of the fragility of our embryonic defense, we would find such Soviet moves highly provocative, and respond in kind. A budding BMD system is therefore a catalyst for an acceleration of the offensive arms race, not for reductions in offensive arms, as many SDI advocates claim.

SDI is often portrayed as a benign research program. But a program launched from the Oval Office, described as a vital element in the nation’s future strategic posture, and funded at already so lavish a level, is not merely a research project. It will not be so treated by the Soviets, no matter what we may say or believe. Modern military systems take many years to develop, so the Soviets will feel compelled to initiate programs to counter the still unborn U.S. defense. Hence SDI is likely to enmesh us in a more dangerous offensive confrontation even if it is eventually abandoned before any defenses are deployed. Those who find this farfetched have not learned the saga of MIRV—the multiple-warhead ICBM. We invented MIRV’s as a BMD countermeasure. When the Soviets installed a rudimentary ABM system, we forged ahead with MIRV development, and then to deployment after the ABM treaty prevented the Soviets from installing a defense that made MIRV’s necessary. The Soviets then followed suit. As a result, the incentive for a preemptive strike has grown because a single warhead can destroy many MIRVed enemy warheads before they are launched. Now there is a consensus that MIRVing was a dangerous mistake; former MIRV advocates such as Henry Kissinger look back fondly to the days of one warhead per missile.

We are also disturbed that the mere prospect of lavish funds is already giving SDI a life of its own. With jobs, university research, profits, and promotions at stake, such an enterprise can quickly turn into a juggernaut that cannot be stopped even when it is clear that its goals are unattainable.

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Many officials now realize that SDI holds no promise for population defense, and so ersatz rationales are coming into vogue. The most popular is that a partially effective BMD would bolster deterrence because defenses would compound the problem of planning an attack.3 True enough, if the offense stays frozen while the defense is installed. But each superpower’s highest priority is a nuclear arsenal that can, with full confidence, penetrate to its opponent’s vital targets. Only technologies far more robust and inexpensive than anything now dreamed of could alter that priority.4

Another fashionable rationale is that even a modest BMD could protect us from accidental launches and from terrorists. But protection from accidental launch by the superpowers does not require space weapons. Devices installed on ballistic missiles to destroy them on receipt of secure, encrypted radio messages would suffice. And attack by terrorists would hardly come via ICBM. Delivery of nuclear explosives by plane, ship, or diplomatic pouch would be far easier. A nuclear weapon hidden in a bale of marijuana would apparently find ready entry into the U.S. The cost of one laser battle station uselessly orbiting would pay for legions of secret agents who could actually grapple with this threat.

There are those who favor SDI because they believe it best exploits the great U.S. advantage in high technology. Their position seems to be supported by the apprehension that Soviet leaders express so vigorously about SDI. Is that not enough reason to pursue the program?

We have observed and participated in the nuclear competition since its inception. Thanks to U.S. technological superiority, virtually every new technical initative has come from the United States: the fission bomb, the hydrogen bomb, the intercontinental bomber, submarine-launched missiles, high-accuracy ICBM’s, MIRV’s, and high-accuracy long-range cruise missiles. The only significant Soviet initiative was the ICBM itself, but our ICBM’s quickly surpassed those of the Soviets in both quality and numbers. The net result has been a steady erosion of American security. There is no evidence that space weapons will be an exception. It is true that we have a significant edge in all the technologies that strategic defense would depend on. But in the nuclear era a sophisticated defense can be foiled by relatively rudimentary means. Which is easier: the construction or the disruption of an exquisitely shaped mirror 30-feet across which must swiftly turn from one target to another with very high accuracy? Moreover, it is cheap to build devastating weapons that could readily penetrate our exorbitantly expensive “shield.” Unless there is a breakthrough in defense as revolutionary as nuclear weapons themselves, the strategic offense will reign supreme.

But if so, why are the Soviets so opposed to SDI? Because they are exceedingly cautious, and have been playing catch-up with American nuclear technology since 1945. Soviet military planners are obliged to take American pronouncements, however implausible, much more seriously than American strategists, and will respond with an offensive build-up and by expanding their already significant BMD research effort.5 They seem to recognize that this will require vast expenditures they can ill afford, and that the net result will be a decrease in their national security. The same would be true for us.

We should vigorously exploit our technological advantage to acquire military intelligence about the Soviet Union, to strengthen our strategic command-and-control systems, and to reduce our reliance on nuclear weapons. The search for new BMD techniques must go on, but the distinction between research and deployment should not be blurred. But in assessing military technologies we must recognize that any attempt by either superpower to increase the threat to the other’s survival will soon redound to its own disadvantage.

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We now return to Mr. Jastrow’s caricature of our case against SDI. He would have readers believe that the prospects for SDI can be decided on the basis of just two numbers that we had calculated incorrectly in our earliest report, Space-Based Ballistic Missile Defense (Union of Concerned Scientists, March 1984); and that our “many major errors . . . go in one direction only—toward making the President’s plan seem impractical, costly, and ineffective.”

What did we set out to do? Since there is no plausible concept for strategic defense, we sought to fill this void. To that end the technical portions of our report assessed separately the interception mechanisms; illustrated the magnitude of the defender’s task by estimating the size of the defensive system required in the absence of all countermeasures; and examined a large variety of countermeasures. A realistic net assessment would integrate the last two items, and incorporate the likely enhancements of Soviet offensive capabilities. Had we carried that through in a hard-nosed fashion it would have led to the conclusion that the cost and size of the defensive system are unbounded. Why? Because the largely unknown defensive technologies, whose ultimate effectiveness is still a matter of speculation, would be pitted against prodigiously effective weapons and many known countermeasures invented during twenty-five years of BMD research. We firmly believe that countermeasures will carry the day into the foreseeable future.

Mr. Jastrow’s two make-or-break numbers are the size of the laser constellation that would have to be in orbit and the weight of a neutral-particle-beam weapon. Regarding the satellite number, he claims that “the whole ‘Star Wars’ plan rested on this one point.” But it is at least as important whether orbiting lasers could themselves withstand attack. As for neutral-particle-beam weapons, he asserts that they are “that most promising destroyer of Soviet missiles and warheads,” but neglects to mention that once fast-burn boosters are developed they would be completely shielded from such beams by the atmosphere—the reason we relegated our discussion of the characteristics of such devices to a technical appendix.6

Mr. Jastrow’s allegation that our work contains “many major errors” is both false and undocumented. We erred twice in our first report: in arriving at the number of 2,400 satellites and in estimating the weight of the particle-beam weapon; but these errors had hardly any bearing on our overall assessment of SDI, were corrected in public at our first opportunity five weeks after the initial report was issued, and do not appear in any of our subsequent publications.

The calculation of the number of satellites is not simple. For example, the “fine work by the theoretical physicists at Los Alamos,” to which Mr. Jastrow alludes,7 makes just the mistake that we had made, even though it appeared four months after our report was publicly corrected. The claim that “the experts had been looking at this problem for more than ten years, and the accurate results were well known” is not correct.

How many satellites must then dance on top of a laser beam? Mr. Jastrow implies that the calculation that produces the smallest number of satellites is the most accurate, a clear absurdity. A small satellite fleet is much more vunerable than a large one. Indeed, there is no “right” number of satellites, for it depends on a host of unknown performance parameters, the nature of the attack, etc. Given the present level of ignorance, all such calculations are based on ad-hoc assumptions of varying degrees of implausibility. They are meant to be illustrative, and bear no relation to actual designs, since they all ignore a host of factors that would greatly increase the number of satellites. Taking the rather small differences in assumed parameters into account, our corrected estimate of 300 laser stations is consistent with those by Carter, Drell et. al,8 a fact Mr. Jastrow neglected to mention.

Unfortunately, Mr. Jastrow has failed to notice that he is impaled on his own sword, blunt instrument though it may be. “Everyone acknowledges that these satellites are going to be extremely expensive; each one will cost a billon dollars or more,” he says. Quite so. What would be the cost trade-off if the Soviets were to deploy a cluster of 3,000 small three-warhead fast-burn ICBM’s at a cost of about $50 billion?9 Let us accept Mr. Jastrow’s favorite satellite-number calculation,10 and his cost per satellite. We then find that it would cost the U.S. $1 trillion to deploy the additional space defenses required by this new $50 billion threat!11

Mr. Jastrow has painted a picture of the Senate hearing at which our errors were rectified that does not conform with the hearing record.12 He asserts that our statement on the particle-beam weapon ended with the sentence: “Our colleagues have pointed out that the area could be increased after the beam leaves the small accelerator.” Mr. Jastrow then charges us with deceiving the Senators because we did not say that this correction brought with it a great saving in weight. But that was not all that happened. The written testimony of our witness, Richard L. Garwin, distributed before the hearing to the press and the committee, and reproduced in the hearing record, actually reads: “. . . leaves the small accelerator, saving a great deal of weight” (emphasis added). Before our witness took the floor, Donald Kerr, the Director of Los Alamos, had said:

I think the UCS report in many ways helps to illustrate the great difficulty involved in first devising and then developing the technology that might be used for strategic defense. They have properly focused on the concerns with command and control, countermeasures, and vulnerability. In some cases I think their analysis has either been overly simplified for the purpose of the public document that it is, or at least in one case, they are totally in error.

Kerr then described our error concerning satellite numbers, and explained how we had overestimated the weight of the particle-beam weapon. He then went on to say:

So I think on the one hand UCS has done a service to the country in raising these issues. I would hope that a longer-term, more sophisticated analysis, albeit one still in the open unclassified literature, might dispel some of the inaccuracies that are also in it.

That analysis was already under way, and is continuing. It is reflected in our October 1984 Scientific American article and in our book, The Fallacy of Star Wars. When our witness testified, there was little point in going over these errors yet again.13

The allegation that we systematically tilted the case against “the President’s plan” is untrue. In fact, we granted it every benefit of the doubt allowed by the laws of physics: beams that would be aimed instantly from one booster to the next without ever missing; laser weapons having a lethality far beyond that for which not even conceptual designs exist; no redundancy to compensate for attrition due to enemy action; no growth in the size and capability of the Soviet ICBM force. No military system in history has ever attained the level of perfection that we granted to “the President’s plan.” (One of us, Richard L. Garwin, even made an original suggestion that greatly improves the prosspects for the ground-based laser scheme.)

Mr. Jastrow opens his attack on our treatment of countermeasures by admitting that “I am not an expert in this dark area,” and then reveals that (always anonymous) professionals of his acquaintance “regard many of [the UCS] proposals as bordering on inanity.” His rendition of our treatment of countermeasures is another caricature. It is he who emphasizes “tricks” like spinning the missile or “putting a shine on it.” We focused on techniques that would prevent accurate targeting on the booster, on measures that would greatly increase the power levels needed for destruction, and on the inherent vulnerability of spacecraft. He would also have readers believe that decoy balloons are a kind of schoolboy prank, but in reality they have been studied for over two decades14 by “defense professionals,” and are taken very seriously.

This picture of us as babes in the cruel woods of countermeasures does not wash. One of us (Richard L. Garwin) recently participated in the Discrimination Countermeasures Panel of the Army’s BMD Program Office. We (in particular Richard L. Garwin and Kurt Gottfried) have had repeated contacts with senior members of the Fletcher panel. They have given our countermeasure suggestions serious consideration in those few cases where they had not already been studied by the panel. Since some of these men are devoted advocates of SDI, and not shy, we wonder why these charges of “inanity” have not been voiced in public, but have been whispered only into Mr. Jastrow’s ear.

Mr. Jastrow seems perplexed as to how some of “the giants of 20th-century physics” could have “lent their names” to an effort that is “pretty good for high-school students, but not good enough to stand up to more than a thirty-minute scrutiny by the defense professionals.” He attempts to resolve his paradox by quoting Lowell Wood of Livermore: “Is Hans Bethe a good physicist? Yes, he’s one of the best alive. Is he a rocket engineer? No. Is he a military-systems engineer? No. Is he a general? No.”

As this quotation is intended to discredit all our work on these matters, we reluctantly respond. Three of us (Hans A. Bethe, Richard L. Garwin, and Henry W. Kendall) have together had a total of over eight decades of extensive experience with a wide variety of military systems, including BMD technologies and countermeasures, extending to nuclear-weapons designs and effects and missile-and-reentry-vehicle development. Another (Carl Sagan) has a twenty-five-year continuing involvement in the development of major U.S. space projects. While none of us is a general (in contrast, we presume, to Messrs. Jastrow and Wood), a member of our study panel, Noel Gayler, is an admiral who has served as Commander-in-Chief of all U.S. forces in the Pacific, Director of the National Security Agency, Assistant Chief of Naval Operations for Research and Development, and as Deputy Director of the Joint Strategic Target Planning Staff, which is responsible for the operational plans for all our strategic-nuclear forces.

Mr. Jastrow concedes that we did not engage “in a deliberate, conscious effort to deceive,” but surmises that our “rational judgments [were] clouded by ideological preconceptions.” What are these “preconceptions”? A defense against Soviet missiles, he quotes us as believing, would “‘have a profoundly destabilizing effect on the nuclear balance, increasing the risk of nuclear war,’” and “‘could well produce higher numbers of fatalities’ than no defense at all.” But those are not ideological preconceptions. They are the unhappy conclusions to which our analysis has inexorably led. We stand by them.

Hans A. Bethe
Richard L. Garwin
Kurt Gottfried
Henry W. Kendall
Carl Sagan
Victor F. Weisskopf

Cornell University
Ithaca, New York
Massachusetts Institute of
Technology
Cambridge, Massachusetts

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To the Editor:

Robert Jastrow attempts to defend “Star Wars” by criticizing other analysts rather than by setting forth his own analysis. This approach would be inconclusive even if Mr. Jastrow were correct. As it happens, Mr. Jastrow’s four criticisms of the Congressional Office of Technology Assessment (OTA) Background Paper which I authored are technically in error. His essay therefore does not offer a serious alternative treatment of this vital national-security issue.

Let me take the four points in turn.

Mr. Jastrow’s first and main criticism rests on his proposition that if the Soviet Union increased its arsenal of missiles by a certain factor to try to overwhelm a U.S. laser defense, the U.S. would have to increase its constellation of orbiting lasers by the square root of that factor. This is wrong. The true dependence is closer to a direct proportionality, which the OTA report uses. Mr. Jastrow’s proposition would be true if Soviet missiles were distributed uniformly over an enormous area and the U.S. laser satellites were at the same altitude as the missiles. These are hardly good approximations to the real world, where Soviet missiles are deployed in a band stretching from east to west across the Soviet Union and the lasers are in space. Careful calculations making few simplifying assumptions have recently been completed by competent government scientists, notably at the Lawrence Livermore Laboratory. Mr. Jastrow’s most misleading error, of course, is implying that constellation size is the key to judgments of the plausibility of “perfect” defense, whereas in fact it is a relatively insignificant issue.

Second, in his footnote 10, Mr. Jastrow criticizes a pedagogical device used in the OTA report, which involved deploying satellites in clusters. This short-cut has little effect on most calculations, since time averages of the constellation coverage enter these calculations. This pedagogy was intended to avoid confusing the reader, but seems to have confused Mr. Jastrow, who thinks it is a serious “error.”

Third, Mr. Jastrow misunderstands the calculation of the number of terminal interceptors needed for nationwide coverage. One thousand defensive batteries are needed for nationwide defense because the missile interceptors in each battery have limited range, not because “1,000 sites in the United States need to be defended,” as Mr. Jastrow supposes. The OTA report makes clear that 280,000 interceptors would be needed only if one aspired to a literally leakproof defense that would prevent all Soviet warheads from detonating on U.S. territory. The point of the calculation was to show how absurd that aspiration is. Mr. Jastrow got the point, but missed the irony.

Fourth, Mr. Jastrow claims that the OTA report said that one-tenth of an inch of lead could shield a Soviet booster from a neutral particle beam. This is indeed untrue, as Mr. Jastrow suggests, but the report does not say any such thing. Mr. Jastrow has confused “a few centimeters of lead” on page 49 of the OTA report with “a few grams per square centimeter” on page 50. The point made on those pages was that covering the entire upper-missile stage rather than just parts of it with enough shielding is impractical, a point with which Mr. Jastrow agrees but thinks the report missed.

Mr. Jastrow is therefore wrong on every single point. But there is an interesting pattern to his errors. Last July some Defense Department contractors, in an equally clumsy attack on the OTA report, made exacty the same spurious “criticisms”! How did Mr. Jastrow hit upon precisely the same points as these contractors? Obviously he was simply parroting them, unaware that they were incorrect.

It is furthermore a matter of public record that OTA convened a panel last summer to review these criticisms of its report. The results of this review were conveyed by OTA’s Director to Congress and to the Department of Defense. The panel consisted of Charles Townes (Nobel laureate, discoverer of the laser, and adviser to Secretary of Defense Caspar Weinberger), William Perry (former Under Secretary of Defense for Research and Engineering), and General Glenn Kent (USAF, retired). This panel also found no substance to precisely those criticisms that now, six months later, Mr. Jastrow “discovers.”

Robert Jastrow has taken up the lonely task of championing the notion of perfect defense of the United States, a task that is widely agreed to be a poor basis for the Strategic Defense Initiative’s research program. To succeed he will need to ask those who are aiding him to keep him better informed.

The issue of strategic defense is not a simple one of “for” and “against.” There are many shades in between. The dim prospect for leakproof nuclear defense is a fact that will not be dispelled by shooting the messenger. Moreover, recognizing that fact does not end, but just begins, a serious discussion of other missions for missile defense. COMMENTARY would serve its readers better by drawing out this variety of views rather than by seeking simplistically to set up opposing camps.

Ashton B. Carter
John F. Kennedy School of Government
Harvard University
Cambridge, Massachusetts

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To the Editor:

I always look forward to the writings of Robert Jastrow, who manages to be lucid when analyzing the most complex subjects. All the more bewildering, then, his paragraph disposing of decoy balloons.

The picture he paints of laser beams sorting out the decoys from the warheads, after which particle or other beams go after the warheads, somehow does not jibe with my vision of one bullet hitting another, both traveling at enormous speed through the immensity of space. How does one “observe” the recoil of a tapped balloon at such great distances and blazing speeds? Are all the balloons tapped simultaneously, with separate laser beams? Does the device then remember which ones carry warheads, all the while tracking each one? If each of the balloons must be intercepted for identification, why not use the same number of beams to attack? If it is possible to intercept them all, is it not then irrelevant which of them carry warheads? Please, Mr. Jastrow, this subscriber would appreciate a bit more detail.

A. L. Drumwright
Sarasota, Florida

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To the Editor:

As an engineer, I would like to disagree with one aspect of Robert Jastrow’s defense of the “Star Wars” ABM concept.

His technique for making such a system sound plausible, and for making the possible defensive measures against it sound absurd, is to attribute virtually unlimited ingenuity to those people who are to design the missile-destroying system, and virtual imbecility to those who are to foil it. For example, he says that if the Soviets try, among other things, to spin their missiles and shine them up, “their missile program will be tied in knots.” And what is the fatal flaw in the shininess defense? According to Mr. Jastrow, simply that “no shine is perfect,” and, given time, a sufficiently powerful laser could burn through it. With a wave of his authoritative hand he has implied that we can deliver massive amounts of focused radiative energy against a distant target for as long as necessary, whereas the Soviets will throw in the towel at the very prospect of mirroring their missiles. Is this the kind of meticulous analysis that Mr. Jastrow would substitute for the supposedly biased science of the Union of Concerned Scientists? In reality, there are many pros and cons to the idea of a durable, reflective missile surface. How reflective can a surface be made? Can we allow it to erode like a heat shield while maintaining control of the missile? On the other hand, can we invent a weapon, by an effort which will not tie our military economy in knots, which can overcome with near 100 percent reliability an optimally reflective, robust missile surface?

Such questions are real. One need not be soft on Communism to contemplate them. Perhaps shininess and all other possible defensive measures could be overcome by some attainable, affordable laser technology. However, it is certainly possible that they might not; the idea of missile durability does not “border on inanity.” If Mr. Jastrow really thinks so, then I suggest that his judgment is at least as “clouded by ideological preconceptions” as he claims that of the UCS scientists to be, despite his pose of sweet reasonableness.

Larry Clifford
Bethlehem, Pennsylvania

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To the Editor:

Robert Jastrow’s “The War Against ‘Star Wars’” was, like all his writing, clearly conceived and powerfully delivered. I agree completely with his scientific arguments; they needed to be made. Yet in the end I was alarmed and frustrated; Mr. Jastrow has provided the right answers, but in doing so he has legitimized some very wrong questions.

The most crucial fact in this entire debate is one that has been totally ignored: “Star Wars” is not an American initiative, it is a response. The Soviet Union has the initiative. . . .

The data supporting this statement are easily researched; they have been available in the popular press for at least seven years, and important scientific clues have been available in technical journals for nearly a decade before that. The most important article, “Soviets Push for Beam Weapons,” was published in the May 2, 1977 issue of Aviation Week. The intelligence data contained in the article suggested that the Soviet program was at that point already six to ten years old and was very broad and deep. Jane’s Defense Weekly, this year, reported that the Soviets are clearly ahead despite the very broad industrial base America can draw from.

The ramifications of this simple fact are enormous. For instance, Mr. Jastrow excuses the Union of Concerned Scientists on the grounds that “their rational judgments can be clouded by their ideological preconceptions.” Yet most of these scientists, led by Harold Brown, were deeply involved in the effort to discount all the evidence of the Soviet program throughout the 70′s. Interestingly, this brought them in direct conflict with Air Force intelligence and the data gathered by reconnaissance satellites, the very sources these same scientists claimed could be relied upon for verification of SALT provisions, negating the need for on-site inspections. No, these scientists are not innocents, they are quite familiar with Soviet efforts in this field. . . .

But the more important issue is the way such weapons tie in with the evolving strategic picture. The Soviets already possess a first-strike capability, an existing ABM system which violates the ABM treaty and forms the basis for a multilayered ballistic-missile-defense system, and an extensive civil-defense program. Were they to succeed in being first to emplace even an austere version of “Star Wars,” the temptation to launch a first strike would very likely be irresistible. Whatever would be left of the U.S. strategic forces after a first strike might well be handled by the defensive system they are currently building. Even if events proved them wrong, once they acted upon obvious calculations, the world would see a nuclear war. Thus, Mr. Jastrow’s tacit acceptance of the UCS argument that “Star Wars” is potentially destabilizing legitimizes a very wrong-headed perception of reality—the situation is already seriously destabilized and the Strategic Defense Initiative is a minimum attempt to restabilize it.

Even the MX missile plays a significant role in the accurate perception of “Star Wars.” All our current ballistic missiles, both ICBM’s and SLBM’s, are so weight-limited that they offer no potential for modifications which might make them effective a decade from now. Only MX and a projected version of Trident provide sufficient flexibility to incorporate a response to whatever emerges from the massive Soviet beam-weapon program. Midgetman, against any potential Soviet defense system, is an anachronistic joke.

One more point—no matter how permeable or vulnerable the space battle stations envisaged in the Strategic Defense Initiative might be, in launching a first strike the Soviets would have to deal with them first. Such action eliminates all possibility of surprise. Indeed, it eliminates even the very idea of a first strike, since action against American satellites would fully justify a launch-on-warning stance for American strategic forces, as well as immediate counter-strikes against Soviet satellites and any battle stations. The corollary of this time-sequencing is that, while launching a thousand complex missiles within thirty minutes is a very difficult technical feat, launching sufficient numbers to overwhelm a “Star Wars” defense within the time-frame necessary to achieve an effective first strike is likely to remain impossible for quite a while. . .

Thomas J. Rath
Altadena, California

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To the Editor:

Robert Jastrow’s dismissal of the Union of Concerned Scientists’ proposals for countermeasures to the “Star Wars” defensive system leaves me more than a bit confused about how thoroughly the author and the unnamed “experts” to whom he so often refers understand the criticisms they rebut.

Mr. Jastrow seems to refute the charge that cheap “balloon” decoys could degrade the performance of a defensive system by conceding the validity of the point. Decoys are intended to force a defensive system to waste precious time and energy by engaging both decoys and balloon-enclosed warheads. Mr. Jastrow’s announcement that “a sharp pulse of laser light” will cause decoy balloons to reveal their identity by their rate of recoil comes as no revelation to this inquisitive citizen, as I have never heard a “Star Wars” critic argue to the contrary.

Mr. Jastrow seems also not to have thought through his remarks on the utility of spinning and shining ICBM boosters as a means of complicating the job of defensive-beam weapons. Hans A. Bethe, Richard L. Garwin, and others have proposed the use of a strippable outer coating on missile boosters to reduce the dulling effect that launch would have on a booster shined to reflect laser light. The coating would shed once the missile moved above the atmosphere and within the range of laser weapons.

As for Mr. Jastrow’s observation that a laser firing in pulses would be able to concentrate its energy on a single point on a spinning missile, I must say that a lot of confidence is placed in the laser weapon’s ability to track and determine the rate of spin of a fast-moving object at long range. A simple countermeasure to a tactic such as Mr. Jastrow describes would be to vary the rate of spin of the missile once incident laser light is detected.

Specific counter-rebuttals aside, several of the tendencies apparent in the article were disturbing to me. Mr. Jastrow’s trust in the proclamations of his communicants in the defense community, whose “ideological preconceptions,” while unexamined, must certainly be as clouding of judgment as those of the UCS scientists, and his representation . . . that only professional military-systems analysts can assess competently the merits of the “Star Wars” proposal, lead me to suspect that Mr. Jastrow never undertook a dispassionate analysis but sought instead opinions that reinforced his original enthusiasm for the proposal.

I must note, also, that there is no unanimity of opinion on “Star Wars” within the traditionally pro-defense community. Richard D. DeLauer, Under Secretary of Defense for Research and Engineering, testified before the House Armed Services Committee that “any defensive system can be overcome with proliferation and decoys, decoys, decoys, decoys.” Edward Teller has criticized defensive proposals that depend on satellite-based systems because such systems are “costly to put up and cheap to shoot down.” . . .

The most bothersome of Mr. Jastrow’s prejudices is his refusal to see criticisms of “Star Wars” for what they are, that is, attempts to inform the public of the vulnerabilities of a system only the putative virtues of which have been presented publicly by the Reagan administration. Mr. Jastrow does not detail the “promising new developments” that might defend components of a defensive system from space- or ground-based attack. I, and I am sure others, would appreciate any information on progress toward remedying the problem of satellite vulnerability. . . .

Edward F. Hennessey
Wethersfield, Connecticut

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To the Editor:

Robert Jastrow states that “90 satellites—and perhaps somewhat fewer—are needed to counter a Soviet attack.” His argument, however, contains one profound flaw. He deals solely with the defensive systems needed to neutralize a massive attack of Soviet land-based missiles. The actual attack scenario would almost certainly include substantial numbers of submarine-launched missiles as well as cruise missiles that can be fired from a variety of platforms, both moving and stationary. This consideration would exponentially magnify the task of the defense. Indeed, even if the oceans were rendered “transparent” by evolving technology, the cruise missile, relatively inexpensive and readily camouflaged, might easily overwhelm any combination of defensive systems.

Other considerations abound, such as the destabilizing nature of any truly effective defensive system and the obvious inference that its deployment might trigger the very suicidal confrontation that all nations seek to avoid.

I would also assume that any defensive system resulting in the physical destruction of thousands of warheads would result in a literal rain of radioactive bomb components into the atmosphere and thence to the surface of the earth. I wonder if Mr. Jastrow’s celluloid computer has taken this into account.

David R. Perles, M.D.
Chief Radiologist
Woodruff Community Hospital
Long Beach, California

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To the Editor:

Even if a satellite-type ABM system could be made 100-percent effective against ICBM’s, the U.S. would still be vulnerable to submarine-launched ballistic missiles, or cruise-type missiles launched from bombers.

Moreover, the deployment of the “Star Wars” system, intended only for defense, could lead to a far more precarious situation than we are in today.

If it were possible to place a working satellite system above the Soviet Union, our weapons-controllers would be tempted to arm those satellites with nuclear warheads; overwhelmingly tempted. The Soviets would certainly react, not necessarily by trying to disrupt or destroy our “Star Wars” system, but by deploying one of their own, albeit with inferior safety controls.

If such systems are deployed, they will dangerously diminish the response time to suspected attack. Instead of fifteen to thirty minutes, the President or Premier will have about sixty seconds to respond to signs of an adversary’s nuclear strike. Hence, both the U.S. and Soviet Union would almost certainly revert to a “launch-on-warning” system, computer-controlled and unalterable by human judgment.

Worse yet, the Soviets, knowing the inferiority of their own radar and signaling equipment, might place their whole nuclear network on a state of constant alert—in which the “red button” does not initiate but merely restrains the launching of their nuclear missiles. Hence, if that trigger were destroyed, a Soviet nuclear attack would automatically follow.

Allen Finegold
Amarillo, Texas

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To the Editor:

Robert Jastrow exposes and dramatically debunks some of the errors committed by the enemies of the Strategic Defense Initiative, or “Star Wars” proposal, in their blind attempt to kill this program. However, in addition to claiming erroneously that the hardware required to implement SDI would be virtually impossible to develop, opponents also offer flawed arguments that it would violate the ABM treaty and would stimulate a new defensive arms race.

One way SDI opponents bias their discussions against the feasibility of the hardware is to confine their attention to a perfectly leakproof defense . . ., even though the cost and technical risk of a partially effective nuclear-missile-defense system would be far less than the cost of a leakproof defense. Also, a leaky nuclear-missile defense would strengthen deterrence significantly by drastically reducing Soviet confidence in their ability to launch a successful first-strike nuclear attack. . . .

In an apparent attempt to frighten the public, opponents also declare that SDI violates the terms of the ABM treaty. But SDI is a research program of the kind that is not prohibited by the ABM treaty; it contains no development, testing, or deployment activities. If, in the future, the U.S. determines that it would be in the national interest to go beyond the research stage, then a new kind of activity not in the current SDI program would have to be initiated, and the U.S. would have to determine whether the new activity would violate treaty limits.

This attempt on the part of those who oppose SDI to mislead the public blurs the distinction between the administration’s SDI program, which is well within treaty limits, and some hypothetical program, which has neither been proposed nor planned, and which may or may not confront the treaty limits.

Arguments that SDI would trigger a new defensive arms race are contrary to the facts because the Soviets have been racing in this direction since well before the signing of the ABM treaty in 1972. During the past dozen years, they have developed a new, transportable, phased-array ABM radar and a new interceptor missile, both of which could be deployed rapidly should the Soviets choose to do so. (The U.S. has no equivalent deployable capability.) They have also upgraded the Moscow ABM defense system (the U.S. has no defense system), have deployed additional phased-array radars on their periphery for ABM target-acquisition support, and are now developing an advanced anti-tactical-missile-defense system that definitely has value for strategic-missile defense.

The attack against SDI seems to assume that all of the initiative in strategic defense lies with the U.S. It ignores the chilling and fairly obvious possibility that the Soviets will find it advantageous to accelerate their own strategic-defense programs or even break out of the ABM treaty. The political costs to the West of a substantial Soviet lead or break-out in defense would be great.

SDI should be pursued to give us a chance to strengthen the security of the U.S. and the rest of the world by making nuclear-ballistic missiles less useful as instruments of politics and war.

Marvin King
New York City

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To the Editor:

Robert Jastrow faults the Union of Concerned Scientists for some unfortunately flawed calculations concerning the size and weight of satellites required to set up a “Star Wars” defense against Soviet ICBM’s and the numbers of such satellites that would be needed. But the case against a “Star Wars” defense is far more substantial and is based upon serious technical matters. The numbers and dimensions of “Star Wars” satellites are significant only if the X-ray lasers, optical lasers, and particle beams will actually function. The UCS’s The Fallacy of Star Wars raises many doubts about these weapons, doubts which Mr. Jastrow ignores in his article. . . .

The use of X-ray lasers powered by nuclear explosions and launched at the time of a Soviet attack would require building a new fleet of submarines to launch the “pop-up” X-ray laser weapons, since we have no satisfactory land bases close enough to Soviet silos to enable us to intercept Soviet ICBM’s in the short time which will be available. We would also have to build attack submarines and surface vessels to protect the X-ray laser submarines. The X-rays of this type of laser are unable to penetrate the atmosphere, . . . and the Soviets could easily shorten the boost phase of their ICBM’s to end before the missiles have left the atmosphere. The Union of Concerned Scientists has concluded that “the X-ray laser is not a viable BMD weapon.” . . .

In addition, . . . the concept of using the weapons as “pop-up interceptions” is not feasible. The Soviets have located their silos in the area of the Trans-Siberian railway at about 55 degrees latitude. The area closest to these silos that American forces can reasonably use is the Arabian Sea to the south of Pakistan, about 23 degrees latitude. The X-ray lasers would have to be launched to a point where they can fire at the Soviet ICBM’s while they are out of the atmosphere and still boosting. Assuming an interception altitude of 110 kilometers, the distance from a submarine to a satisfactory interception firing point for an X-ray laser would have to be at least 1,200 kilometers.

Assuming far more powerful propellants than those currently in use, the minimum flight time of an X-ray laser from launch submarine to interception-firing point would be 120 seconds. To these 120 seconds we have to add the time involved in the decision to launch the X-ray lasers: the processing and verification of satellite warnings that ICBM’s are being launched: the acquisition, processing, and transmssion of targeting information; and the firing of the X-ray lasers from the submarines. According to John Steinbruner, in the January 1984 issue of Scientific American, 120 seconds would be needed merely to process and verify the data from the early-warning satellites. Regardless of how long this takes, the 120-second flight time of the X-ray lasers is far short of the 50-second booster time the Soviets would be able to achieve for their ICBM’s.

Submarines are also crippled by their inability to fire all their X-ray lasers in a single salvo. The first launch would give away the submarine’s position and invite a Soviet attack.

The interception of Soviet ICBM’s during their boost phase is the most important consideration of the “Star Wars” defense. The large ICBM’s are easier to locate and track than relatively small warheads after they have been released from the final stage of ICBM’s. The Reagan administration’s own Defense Technologies Study Team, headed by James C. Fletcher, agreed that a “Star Wars” defense is impossible unless the great majority of Soviet ICBM’s were intercepted during the boost-phase of their flight. X-ray lasers are clearly not feasible for boost-phase interception. The much-touted particle-beam weapons fired from orbiting satellites are also not feasible because of the effect of the atmosphere and the magnetic field of the earth upon particle beams. The particles from neutral-particle-beam weapons would, if fired into the atmosphere, encounter air molecules in the upper atmosphere and disintegrate into charged particles which would be pulled by the earth’s magnetic field, resulting in a steady increasing of the width and consequent decreasing of the intensity of the particle beam. . . .

Optical lasers, which emit light in the infrared (chemical lasers), ultraviolet (excimer lasers), and visible (free-electron lasers) portions of the spectrum, may also be unsuitable for interception of Soviet ICBM’s during their boost phase. The wave nature of light means that the edges of the beams will tend to spread out increasingly over increasing distance. This means that the size of a spot upon which a laser can be focused increases in proportion to the distance from the target. Since the energy carried by a laser beam spreads over distance, the effectiveness of a laser weapon decreases over distance in proportion to the square of the distance. The energy needed for optical lasers suggests they could be functional only in low orbits where they would be vulnerable to attack from Soviet anti-satellite weapons of various sorts. Clouds of fine abrasives, for example, could be used to damage the laser mirrors. Clouds of light-absorbing substances could be used to limit the efficiency of the mirrors. Battle stations in space are much more vulnerable than boost-phase ICBM’s to a wide variety of rather crude attacks.

The “Star Wars” defense would have to have battle-management systems that would deal with hundreds of thousands of objects. For this we would need computers able to carry out at least hundreds of millions and probably billions of authentic operations each second. Even if huge strides in computer technology were to produce hardware able to perform such gigantic numbers of operations per second, other problems connected with the implementation of a “‘Star Wars” defense would probably never be resolved.

One very serious problem is that of designing and developing the programs (software) needed to direct the defense computers. Experience with the software involved in other defense systems as well as non-defense software indicates it will be extremely difficult—if not impossible—to create software capable of functioning properly in a nuclear attack. . . .

We could never be reasonably confident that a “Star Wars” defense with all its complex facets would function harmoniously and effectively during a strategic-nuclear attack. The “Star Wars” defense would be a gigantic, intricate assemblage, novel in conception, involving the farthest limits of advanced technology, and required to meet an extremely high performance standard, even though it could never be adequately tested.

Complex designs generate complex problems. All large computer programs contain flaws or bugs which decrease over use but which may never be entirely eliminated. . . . But no amount of simulated battle situations could satisfactorily examine the actual response of a complex “Star Wars” defense system to an actual nuclear attack. This is so not only because of flaws or bugs in software . . . but also because the precise nature of a nuclear attack, along with the enemy’s countermeasures, can never be known in advance. . . .

Joseph Forbes
Pittsburgh, Pennsylvania

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Robert Jastrow writes:

Edward Teller’s letter makes an apt comparison between the controversy over the feasibility of “Star Wars” and the H-bomb controversy of the early 1950′s. Confident in the superiority of American scientists, we were certain at that time that the decision to build the weapon rested solely with us. But we now know that the Soviets were in fact hard at work on their version of the H-bomb as we argued over whether it should be built at all.

Today, as we again debate the wisdom of research on another weapons system—this time, a system that destroys weapons rather than people—we assume that the decision will be made in this country, whereas in fact the Soviet Union is already hard at work on its own “Star Wars” program, and has been for many years. In the twelve years since the USSR signed the ABM treaty, the Soviet Union has, according to Secretary of Defense Weinberger, spent more on strategic defense than it has on its arsenal for strategic offense. Elements of the Soviet missile-defense effort that violate the ABM treaty in particularly conspicuous ways were publicized last October in a report to the President by the General Advisory Committee on Arms Control and Disarmament. Because of this massive Soviet strategic-defense effort, Mr. Teller rightly concludes, our government’s missile-defense program, officially known as the Strategic Defense Initiative, could better be called the Strategic Defense Response.

Soviet emphasis on a defense against missiles, and the total Soviet rejection of Mutual Assured Destruction (MAD), go back at least two decades. Andrei Gromyko called for the deployment of a missile defense by the superpowers in a speech to the UN in 1962, in which he strongly criticized the doctrine of Mutual Assured Destruction. Gromyko said the “balance of fear,” as he called it, kept the world in a “a permanent state of feverish tension.” He compared MAD to a duel in which the superpowers “raise their pistols, aim at each other’s foreheads, and wait for the other to shoot.”

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James A. Abrahamson’s letter underscores the fact that attacks on his program by a few academic scientists are entirely at variance with the rapid technical progress being made by thousands of scientists and engineers who work full time on the “Star Wars” project. Even without access to classified information, a diligent reader of aerospace trade journals can gain tantalizing hints of extraordinary developments taking place in the basic technologies of missile defense.

It is also reassuring to have General Abrahamson, who is in a better position to know than anyone else, agree that various Soviet countermeasures to our defense—highly touted by the Union of Concerned Scientists and discussed in my article—are not holding up well under the scrutiny of the defense professionals. The Soviets have confirmed General Abrahamson’s evaluation of their countermeasures. If they thought the proposals put forward by the Union of Concerned Scientists were truly effective and inexpensive, they would not be trying so desperately to stop our “Star Wars” research. They would encourage us instead to go on with this expensive program that could be so cheaply countered by them. But they are fighting tooth and nail to kill the “Star Wars” project. Clearly, they disagree with the Union of Concerned Scientists and believe that it will cost them a great deal of money and trouble to counter our defense, if that can be done at all.

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Lowell Wood of the Lawrence Livermore Laboratory stresses a very significant point which has been made a number of times in my hearing by scientists working on defense matters. The university scientists who put forward the egregiously flawed arguments against missile defense have been repeatedly and firmly corrected by their colleagues in classified technical discussions that are not open to the public. But, as Mr. Wood notes with exasperation, after failing to make their case to their technical peers, they continue to present the same rejected arguments over and over again to the press and public.

One of the prime examples is the so-called “pop-up X-ray laser,” which requires much additional research and development but holds the promise of being a devastatingly effective destroyer of missiles. In the report by the Union of Concerned Scientists and in the recently published UCS book, The Fallacy of Star Wars, the pop-up X-ray laser is dismissed as a useless device, readily countered by Soviet fast-burn boosters—that is, by missiles that accelerate very quickly and burn out at an altitude of 50 miles or less. One UCS criticism relates to the fact that a fast-burn booster may burn out in the atmosphere at depths to which X-rays cannot penetrate. But this criticism turns out to be invalid when classified information relating to the intensity of the X-ray laser beam is taken into account.

The classified information, Mr. Wood notes, has been presented in face-to-face discussions with the critics, who have not contested the technical points being made. Yet the critics continue to make their pessimistic comments in public where they cannot be countered by the classified facts.

This behavior seems to me and many of my colleagues to be less than responsible.

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I share with George Fishman his puzzlement over the fears of a space-based missile defense expressed by many academics. These fears seem indeed to be “irrational,” as Mr. Fishman says, because the space-based weapons proposed for the “Star Wars” defense are not weapons of mass destruction, and cannot blow up a city or incinerate millions of civilians. The weapons that can do that are on the ground, in silos and submarines. “Star Wars” space weapons do not kill people; they destroy the weapons that kill people.

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The letter by Hans A. Bethe, Richard L. Garwin, Carl Sagan, et al. deals in its first section mainly with the strategic and political dimensions of missile defense. I should like to pass beyond these to the technical issues which were the principal thrust of my article, and take up those in order.

First, Mr. Bethe and his colleagues say that fast-burn boosters protect the Soviets from our neutral particle beams, because the neutral particle beam does not penetrate the atmosphere. The thought here is that the booster will reach full speed in 50 seconds and burn out at an altitude too low to be reached by the beam. But, as my article noted, the neutral particle beam is just as effective against the bus carrying the warheads after the booster has burned out, as it is against the booster itself. If the beam catches the bus early on, while most of its warheads are still on board, the results are just as good for our defense as destroying the booster would have been.

If the Soviets try to escape the neutral particle beam by pushing their warheads off the bus while it is still within the atmosphere, air drag will seriously degrade the accuracy of the warheads, with disastrous consequences for Soviet hopes of taking out our retaliatory forces. That problem might be overcome by putting every warhead on its own mini-bus, with separate guidance and steering rockets. But if the Soviets do that, the extra weight required will substantially diminish the total number of warheads carried on the missile, probably by a factor of 2 to 5. And when the warheads are released, they are still vulnerable to the neutral particle beam during the long mid-course phase of their flight, which lasts many minutes. So, if the Soviets go to the enormous expense and trouble of replacing all their missiles with 50-second boosters—and, as George Keyworth, the President’s Science Adviser, has noted, that means wiping out a fifteen-year investment in their missile force—it will avail them nothing.

In fact, the consensus among the experts is that the fast-burn booster, so highly regarded by the UCS and by Ashton B. Carter in his report to the OTA, is not a useful ploy for the Soviets. This has been pointed out to Mr. Garwin and other critics in classified discussions, but they continue to present their discredited arguments to the public “immune from the criticism of their technical peers,” as Mr. Wood has said.

Not only are fast-burn boosters ineffective against several defenses being designed in General Abrahamson’s program, but there is even some doubt among missile experts as to whether such a thing as a 50-second booster can ever be built on a mass-production basis and perform reliably. A rocket that accelerates from a standing start to roughly 15,000 miles an hour in less than a minute presents horrendous technical problems to the missile designer. Fast-burn rockets tend to explode and are not reliable; they get very hot because they move through the atmosphere so rapidly; and their structure must be stiffened to protect them against the battering forces created by their own acceleration. This last point imposes a heavy penalty on the Soviets, because the added weight must be compensated by the loss of a quarter to a third of the missile’s payload.

Mr. Bethe and his colleagues cite a report submitted to the Fletcher panel that suggests 50-second boosters are feasible, but fail to mention that after examining all the evidence available to it, the Fletcher panel concluded that the Soviets could not hope to deploy a missile of this kind before the 21st century. In the light of these circumstances, many people in the defense community find it impossible to understand why Mr. Bethe and the UCS put so much emphasis on the fast-burn booster as the Soviet response to our defense.

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Turning to the question of the number of satellites needed for our defense, Mr. Bethe and his colleagues dispute my statement that the experts have been looking at this question for more than ten years. My remark was taken from an unclassified report dated May 9, 1984 by O. Judd of Los Alamos. I spoke with Mr. Judd recently and he confirmed the accuracy of the statement.

On this same matter, according to the Bethe letter, I imply that the calculation that produces the smallest number of satellites is the most accurate, which is a “clear absurdity.” Not at all. I only note that the UCS calculations went from 2,400 satellites down to 800, then to 300, and, in the most recent report on the matter by Mr. Garwin, to 162 satellites. This sequence of numbers, which started out at 2,400 satellites, seems to be converging to a result in the neighborhood of 100 satellites, which is where the professionals pegged their results all the while.

Anyone can draw his own conclusions from these facts. My impression is that the UCS theorists first did a hasty piece of work and then, under criticism, did more extended calculations, until finally Mr. Garwin did a careful analysis. Throughout this long learning process, their numbers came down steadily, until leveling off in the neighborhood of the right answer.

Hans A. Bethe and his colleagues allege that there is no right answer because the answer depends on many factors, some of them unknown. But there is a “right” answer to the specific theoretical problem which they addressed. For that particular problem they presented a calculation to the public which turned out to be wrong by a factor of about 24, and in a direction that made the “Star Wars” plan seem very costly and impractical.

The Bethe letter also mentions the “square-root law,” which is critical to the assessment of Soviet prospects for overwhelming our defense, because it indicates that we can overcome a massive build-up of Soviet missile forces with a relatively modest increase in the size of our satellite fleet. Richard L. Garwin’s detailed report of December 30, 1984 concedes the validity of this relationship. Yet the letter from Mr. Bethe and his colleagues states that Mr. Garwin has proven the Los Alamos report to be incorrect under “all but highly artificial circumstances.” How do we explain this contradiction?

The answer is in Mr. Garwin’s paper. He has invented another problem involving satellites and missiles, which is quite different from the problem that was analyzed by the Union of Concerned Scientists in its report, and then in its book, and by Ash ton B. Carter in his report to the OTA, and by G.H. Canavan and his colleagues at Los Alamos, and by C.T. Cunningham at the Livermore Laboratory. In this new problem, Mr. Garwin assumes that 3 seconds are needed, on the average, for a laser to swing around from one missile it has just destroyed, and lock its beam onto another missile. This is the so-called “retarget time,” which was assumed to be zero in all the calculations mentioned above. If the retarget time is indeed as long as 3 seconds, our laser-equipped satellites will be very inefficient at shooting down Soviet missiles, and many more satellites will be needed than the previous estimates assumed. We will lose not only the square-root law, but the entire effectiveness of this part of our defense.

But the design objectives in General Abrahamson’s program call for a retarget time of 0.1 seconds and not 3 seconds. If the retarget time is 0.1 seconds, the results for the number of satellites are not very different from those for zero retarget time. In particular, the important square-root law is valid.

But how can we hope, in a time as short as 0.1 seconds, to rotate the mirror that directs the laser beam, damp down its vibrations, and lock in on a new target? A retarget time of 0.1 seconds would indeed be difficult to achieve if the experts were planning to rotate the mirror mechanically to redirect the beam from one Soviet missile to another. But the “Star Wars” program is probably not going to do that. A part of its funding is going into research on an extraordinary new technology that uses “phase conjugate coatings,” which change the direction of the laser beam electronically in a fraction of a second, leaving the mirror fixed in place. The technique is essentially that used in phased-array radars, which do not rotate like the earlier radars, but sweep the sky electronically. This is a fascinating illustration of the black arts being practiced on the cutting edge of technology by the scientists and engineers working with General Abrahamson.

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Mr. Bethe and his colleagues also take up the critically important question of cost ratios, saying it will cost us a trillion dollars in additional satellites to counter an increased Soviet missile force costing only $50 billion. With a cost ratio like that, we are lost before we start, for clearly the Soviets can overwhelm our defense by outbuilding us. But I have looked into the cost figures, and they turn out to be entirely different from those given by Mr. Bethe and his colleagues.

First, on the matter of the cost to the Soviets of building more missiles, the letter states that $50 billion will buy 3,000 fast-burn, three-warhead, Midgetman-type missiles, including the cost of warheads and silos plus ten years of maintenance. This amounts to about $15 million per missile, or $5 million per warhead. Missile designers do not know yet what a fast-burn missile would cost, because none has been designed or built, but we can get an idea of the cost by using the current life-cycle cost for the MX missile. This is $40 billion for 100 missiles, each containing 10 warheads. That works out to $400 million per missile, or $40 million per warhead.

The cost per warhead for the proposed Midgetman will certainly be more than that, first, because fast-burn boosters are a new generation of missiles that must be built to withstand the stress of high acceleration, and second, because the cost per warhead is greater for small missiles than for big ones. According to Mr. Carter, a fair guess for the cost per warhead of a fast-burn booster is two to three times the corresponding cost per warhead of the MX missile. It is safe to say the cost of the proposed new Soviet missiles is at least $40 million but probably not more than $100 million per warhead. Thus, 3,000 fast-burn Midgetman missiles will cost the Soviets between $400 billion and $1 trillion.

Now for the cost to us of our defensive satellites. Mr. Bethe and his colleagues say we will require an additional 964 missiles to counter the new Soviet satellites. Using the accepted ballpark figure of $1 billion per satellite, this works out to $1 trillion in round numbers. Where does the figure of 964 satellites come from? It rests on the assumption by Messrs. Bethe et al. that the Soviets will cluster all 3,000 new missiles tightly together in one spot. But is it conceivable that the Soviets would do that?

For several reasons, they would not. For one thing, if all the missiles are located in one spot, and all are launched at one time, the times of arrival at their various targets in the United States will be widely different. That means the Soviets cannot effect a surprise attack that would take out all at once our command structure, airfields, submarine bases, and missile silos, since these are located at widely different flight times from any single place in the USSR. Suppose the Soviets try to overcome this handicap by launching their missiles over an extended period of time, so as to achieve a simultaneous arrival at the various targets. Then our boost-phase defense becomes enormously more effective, because we can pick off the Soviet missiles one by one as they rise from their silos.

The so-called “point” launch will create other problems for the Soviets. If they launch from one location at one time, all their warheads and decoys are bunched tightly as they course through space. This reduces the retarget time for our mid-course defense and, again, greatly increases its effectiveness. It also makes the warheads ideal targets for the X-ray laser. Finally, putting all the Soviet missiles in one place increases the effectiveness of our terminal defense as well, because it then becomes difficult for the Soviets to “ladder down.” That refers to a technique for foiling our terminal defense in which the Soviets explode a nuclear weapon far above the missile silo or other target to create a fireball that will blind the ground radars on which our terminal defense depends. The fireball clears the way for another nuclear weapon that explodes and creates a fireball farther down, which clears the way for still another warhead, and so on, until finally the last warhead, swimming through these fireballs, reaches the target. But laddering down is impossible if all the missiles are in one place, unless they are launched at different times, and that is, as noted, disadvantageous to the Soviets for other reasons.

All in all, the last thing the Soviets are likely to do in response to our defense is to place their entire fleet of new missiles at one location.

But if the assumption that they would do this is removed, and the hypothetical new Soviet missiles are assumed to be spread across the Soviet land mass, as Soviet missiles are today, the number of American satellites required to counter their hypothetical attack goes way down. The reason is that the swath containing Soviet missile fields extends nearly a third of the way around the world at these latitudes. This considerably increases the chance that one missile or another in that vast expanse will be within the range of our satellites. The effect is to reduce by about a factor of approximately 3 the number of satellites required for our defense.

But there is more. The estimate of 964 satellites given by Mr. Bethe and his colleagues also assumes that the Soviets will have available to them a fast-burn booster that completes its acceleration from a standing start to full velocity in 50 seconds. This assumption means that each satellite has a very short time in which to attack the Soviet missiles, and therefore can destroy only a relatively small number of them. That means, in turn, that we need a large number of satellites to do the whole job.

As a practical matter, however, the goal of a 50-second booster is so difficult that the United States probably could not attain it until the late 1990′s, and the Soviets are not expected to achieve it until the 21st century. When the assumption of a 50-second burn time is removed, and the more realistic assumption is made that the Soviets will have boosters similar to our MX, which has a 180-second burn time, the number of satellites required for our fleet goes down to 88, or, in round numbers, to 100.

At a billion dollars a satellite, that brings our investment down to about $100 billion, compared to between $400 billion and $1 trillion for the Soviet investment. In other words, the ratio of costs is very favorable to our defense over their offense.

Next, Mr. Bethe and his colleagues take up the matter of the 40,000-ton accelerator, and suggest that my description of their testimony is distorted because I have omitted the important phrase, “saving a great deal of weight.” But I have the stenographic transcript of the hearing in front of me and it does not contain that phrase. Even if that phrase had been in the transcript, it would not have conveyed the full flavor of the difference between 25 tons in orbit and 40,000 tons in orbit; but in any event, it is not there.

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Turning to Ashton B. Carter’s letter, objections are raised therein to four points in my criticism of his analysis. First, Mr. Carter says that the “square-root law,” to which I attribute much importance, is wrong. He refers to calculations by the Livermore Laboratory for support. But the Livermore report confirms the square-root law. I have in hand the Livermore report on this subject by C.T. Cunningham, dated August 30, 1984. It was one of the sources for my article. The report shows that a fleet of 60 satellites in orbit at an altitude of 300 kilometers will shoot down 97 percent of the Soviet missiles in a mass attack from all 1,400 Soviet missile silos; whereas 90 satellites will shoot down the same percentage of the Soviet missiles in a mass launch from 2,800 silos simultaneously. According to the square-root rule, a defense against the increased Soviet missile force should require √2×60 = 85 satellites. But if Mr. Carter’s analysis were correct, and the number of American satellites rose in proportion to the number of Soviet missiles, 120 satellites would be needed to counter the doubled threat. It is clear that the Livermore result is much closer to a square-root rule than it is to Mr. Carter’s result.

Mr. Carter says his hypothetical deployment of satellites in bunches or clusters was a pedagogical device. But his device has an unfortunate effect, for when the satellites are bunched we lose the square-root rule; and when they are unbundled, we get it back again.

Mr. Carter also says I misunderstood his calculations on the number of intercepting missiles needed for our terminal defense. I think I understand them all too well. Mr. Carter estimates our need for thousands of intercepting missiles on the assumption that the Soviets might throw their entire force against one defended site. This leads to a requirement of 280,000 intercepting missiles. That is an implausible number based on an implausible assumption.

In the matter of the lead shield against a neutral particle beam, Mr. Carter suggests that he has been misquoted. Here are his statements. On page 30, his report states that such shielding could be an “attractive countermeasure” for the Soviets. On page 50, the report states: “But if the third stage, say of the MX, were covered with a few grams per square centimeter of lead [about a tenth of an inch], the shielding would weigh as much as several RV’s [i.e., warheads]. On the other hand, if the neutral particle beam is only designed to disrupt or damage sensitive electronics . . . only the sensitive components need be shielded. The weight penalty then becomes small.” It seems to me that my article gives a fair account of the meaning of these remarks.

Finally, Mr. Carter says a panel of experts found no substance to criticisms of his report which had been directed against it by Los Alamos and other groups. Most important among these is a 57-page technical memorandum issued by the Los Alamos Laboratory that contained many detailed criticisms of Mr. Carter’s work, some of them devastating. According to Mr. Carter, the panel refuted these criticisms. But the panel that endorsed Mr. Carter’s report offered no technical arguments whatsoever to counter the carefully reasoned criticisms offered by the Los Alamos scientists. The Los Alamos critique was a serious study, bearing on a matter vitally important to the security of the United States, and its criticisms had to be either rebutted or accepted. The distinguished panel of three experts cited by Mr. Carter did neither. As C. Paul Robinson, Principal Associate Director of the Los Alamos Laboratory pointed out, their benediction, unaccompanied by a technical backup, was without value. Mr. Robinson went on to note that “Los Alamos’s concerns have since been debated in other technical forums, where they have been sustained.”

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In response to A.L. Drumwright, the decoy balloons are tapped rapidly, one after the other, with moderate-energy laser beams, and tracked repeatedly throughout this process to observe their recoil. Computers on our satellites keep track of the separate warheads and decoys and remember the information acquired about each one. As Mr. Drumwright suggests, a little more laser energy could destroy the lightweight decoys, instead of just identifying them. That would mean a different kind of midcourse defense, in which we hit all the warheads and decoys with moderately energetic laser beams, and observe what survives. The surviving objects must be the warheads, and we would go after these with our heavy guns.

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Larry Clifford asks about my objections to the Soviets shining up their missiles. This proposal generates even more problems for them than I mentioned in my article. For one, as the booster accelerates it compresses and heats the air above it, and the plume of hot air sweeps downward around the side of the missile, oxidizing the surface and taking its shine away. Furthermore, the shine itself is obtained by applying a thin coat of reflective material to the missile, but under the high heat resulting from the the laser attack and from atmospheric friction, the coating tends to disintegrate. Finally, the coating has a different coefficient of expansion from the metal skin underneath, and tends to buckle when the missile is heated by the laser beam, leading to its catastrophic failure.

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Thomas J. Rath makes the very interesting point that if the Soviets attempt to destroy the satellites in our space-based defense at the outset, before launching their missiles, they must necessarily give us warning of their attack. For this reason alone, our defenses will make it difficult for them to achieve the element of complete surprise that is essential to the success of a Soviet first strike.

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Edward F. Hennessey asks about the possibility of a strippable outer coating that would keep the missile surface clean and shiny during launch. The trouble with this suggestion is that the strippable coating, which is to be wrapped around the entire missile, must be quite thin, or it will weigh too much and force the Soviets to eliminate several warheads from the payload. It must be sturdy, or air resistance will strip it away. And it must be heat-resistant, because the missile gets quite hot as it rises rapidly through the atmosphere. These requirements are partly contradictory, and reconciling them will not be easy. A substantial amount of development and testing would be necessary to make certain that such a device works well and does not interfere with reliable missile performance. And all this is for a very uncertain gain to the Soviets, because, as noted in my article, when the coating is stripped away and the shiny surface underneath is exposed to attack by our laser beam, the heat of the laser beam will degrade the shine rapidly.

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Allen Finegold and David R. Perles suggest the “Star Wars” defense, even if effective against land-based missiles, will be vulnerable to submarine-launched missiles and cruise missiles. This is not the case. When our boost-phase defense system of approximately 100 satellites is in place, a dozen or so satellites will be over the missile fields of the Soviet Union at any one time, defending us against an ICBM attack. But most of the remaining satellites will be over the oceans and in a position to defend us against missiles launched from submarines. Moreover, for several reasons—slower speed, staggered launches, and dispersed launch sites—the interception of submarine-launched missiles is considerably easier than the interception of land-based missiles.

As for defense against cruise missiles, that is a different problem from defense against ballistic missiles, but not a harder one. In fact, it appears to be considerably easier, because we have many minutes or even hours in which to find, track, lock our beams onto, and destroy the relatively slow-moving cruise missiles. Lasers in space, contrary to some views that have been expressed, are effective against cruise missiles and bombers because their beams, being light rays, reach to the ground. Clouds offer a temporary screen, but a cover of clouds is not likely to exist all the way to the target. And bombers fly above the clouds, at stratospheric heights, on their way to their targets, and are vulnerable to space lasers for hours.

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Marvin King correctly rebuts the charge by some critics of the “Star Wars” research program that it is a violation of the ABM treaty. The language of the treaty states that “Each party undertakes not to develop, test, or deploy ABM systems or components,” but research on missile defense is not prohibited.

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Joseph Forbes’s comments on the usefulness of the X-ray laser are taken from a section of the UCS report which Lowell Wood has shown to be in error. For example, the UCS proposes to have the X-ray laser pop up from submarines located in the Arabian Sea. This relatively distant launch site, about 2,000 miles from the closest Soviet missile fields, would introduce a substantial delay of some minutes in the availability of the X-ray laser for combat—that interval being the time required for the X-ray laser device to climb to an altitude at which the Soviet missile fields are in its line of sight. But, as Mr. Wood pointed out, the eastern Mediterranean and the Sea of Japan are much closer to the Soviet missile fields, and just as accessible to our submarines politically. A launch from these waters largely eliminates the problem cited by the UCS.

Mr. Forbes also says that satellites are necessarily more vulnerable to attack than missiles. This is often stated, but is quite untrue. A satellite, being weightless in orbit, can be defended by heavy armor, guns, and maneuvering rockets. On the other hand, a missile, which must propel itself upward against the backward pull of gravity, cannot afford any substantial amount of armor or shielding, or it loses much of its payload. Today’s military satellites are quite vulnerable because no one has been shooting at them, and we have not bothered to go to the expense of protecting them, but tomorrow’s satellites will be another story. A substantial part of the Defense Department budget is going into research on the hardening of our military satellites.

As for the computations needed in the “Star Wars” defense, as many as several billion operations per second may be necessary, but parallel computer architectures should make this possible. Computing speed is not expected to be a major problem for our defense. The preparation of the complex programs needed is another matter. This is one of the pacing items in the “Star Wars” program, and is receiving a great deal of attention in early planning.

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Footnotes

1 The Martin-Marietta Corporation studied fast-burn boosters for the Fletcher panel, and concluded that they would impose a payload-loss of at most 20 percent, a consensus confirmed in writing by the Deputy Chairman of the panel. Claims to the contrary stem from an abandoned Pentagon attempt to discredit Ashton Carter's Congressional Office of Technology Assessment report on SDI. This misinformation is still being spread (e.g., Wall Street Journal editorial, December 10, 1984).

2 National Journal, July 7, 1984, p. 1316.

3 The diversion of SDI to silo defense is the only rationale that makes technical (though not necessarily strategic) sense. Hard targets, especially expendable silos, could be defended. However, we agree with the administration's Scowcroft commission that such defenses are not needed at this time. In any case, space-based weapons are not suited to this purpose.

4 Indeed, the growth in the offense is bound to exceed any attrition that the defense is likely to attain. The U.S. nuclear threat against Moscow multiplied as soon as we learned that the city was being surrounded by ABM batteries.

5 The Soviets' BMD program seems to be quite similar in character to what ours was before the “Star Wars” speech. We know of no evidence that they are moving toward a comprehensive strategic defense of Soviet society. As the Fletcher panel emphasizes, the most daunting BMD problems are computer-intensive, an area in which the Soviets are exceptionally weak. Indeed, they lag in almost all technologies critical to space-based BMD, so they would be ill-advised to start a contest in this arena.

6 Mr. Jastrow claims that a neutral-particle-beam weapon would only weigh 25 tons. That agrees with our estimate of the weight of the accelerator alone, but ignores the far heavier beam expansion and targeting magnets (see The Fallacy of Star Wars, p. 97).

7 G.H. Canavan, Simple Estimates of Satellite Constellation Sizing, Los Alamos National Laboratory, August 6, 1984. A detailed solution of the satellite-coverage problem has now been found (Richard L. Garwin, to be published) which shows that the “square-root law” of the Los Alamos paper, to which Mr. Jastrow ascribes such importance, is incorrect under all but highly artificial circumstances.

8 S.D. Drell, P.J. Farley, and D. Holloway, The Reagan Strategic Defense Initiative: A Technical, Political, and Arms Control Assessment, Stanford University, July 1984.

9 This comes from the projected cost of the Midgetman missile, though not in its mobile form, and includes the cost of the extra warheads, the silo, and ten years of maintenance.

10 C.T. Cunningham, Report No. DDV-84-0007, Lawrence Livermore National Laboratory, August 30, 1984.

11 This is arrived at from Cunningham's number of 120 lasers for 1,400 co-located boosters with an engagement time of 150 seconds. Our 3,000 fast-burn boosters give an engagement time of 40 seconds, which then gives 120 (3000/1400) (150/40) = 964 laser satellites. (All agree that the number of lasers is proportional to the number of co-located boosters, not to their square-root.) Cunningham assumed a booster hardness that is 50 percent of the Fletcher panel's baseline figure. Were the latter used, the laser constellation would cost $1.9 trillion. This illustrates the sensitivity to assumed parameters.

12 Department of Defense Authorization for Appropriations for FY85, The Strategic Defense Initiative, Senate Committee on Armed Services, 98th Congress, Second Session, April 24, 1984.

13 He did, however, read the phrase at issue, “saving a great deal of weight.” Unfortunately the stenotypist missed precisely one line of written text, and the last word, as restored in the record, was misprinted as “height.”

14 See Richard L. Garwin and Hans A. Bethe, Scientific American, March 1968.

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