Chapter 2
The Elusive Quest For Strategic Defenses
Lessons of Recent History

SDI is but the latest move in a U.S.-Soviet competition to design defenses against nuclear attack and to make military use of space. In a number of respects, however, this stage could turn out to be much different from earlier efforts. Concepts long considered only remote candidates for defensive systems are now being reviewed for development and deployment and, if deployed, would entail fundamental changes in military force structure and strategic doctrine. Short of deployment, even the effort to develop such systems has serious implications for political relations between East and West and within NATO; prospects for international collaboration in space exploration are also threatened. In view of the difficulties posed by SDI, it is especially noteworthy that the earlier phases of the competition to devise strategic defenses have been costly and largely futile.

As these earlier experiences show, technological success in the development of defenses is likely to be only partial and short-lived. The active defenses developed so far are themselves vulnerable to attack, and any gain they have promised to confer has simply provoked offsetting offensive improvements by the other side. The Soviets have made by far the largest investment in strategic defenses, both active and passive. Although these investments may provide some marginal benefits in improved population defense, they cannot possibly prevent a degree of damage to civil and military assets from a massive attack that would be considered devastating by any standard. Further, the near-catastrophe at Chernobyl in 1986 can only have brought home to Soviet military

planners the devastation that can be created by just tens or hundreds, let alone thousands, of nuclear warheads.

It is highly doubtful that SDI, and whatever the Soviets are doing independently and in response, will make any appreciable difference. Unlike previous weapons innovations, however, SDI will probably involve the basing of offensive and defensive weapons in space—a move the superpowers have thus far avoided. And space-based weapons would certainly complicate, and might possibly rule out, any prospect of achieving deep reductions in offensive strategic weapons by negotiation. The militarization of space, which has been under way from the start of space exploration, would reach a new stage in which space will be used not only for the support of terrestrial military operations but as a new dimension of military conflict in its own right.

The efforts to build defenses have hardly been commensurate with the costs—or so experience has taught us. Defense expenditures, although difficult to compare in straightforward dollar-ruble terms, may be analyzed in terms of level of effort. This can be expressed, for the sake of convenience, in U.S. dollar terms. Soviet military procurement costs are calculated this way by both the CIA and the Defense Intelligence Agency, which "estimate production runs and then estimate the level of spending from what it would cost in dollars to produce a similar weapon in the West."^[1]    In the following comparisons, 1986 dollar equivalents will be used.

Like the U.S.S.R., the United States has long made significant investments in developing strategic weapons, but it has not supported the effort at a consistent level of spending. From modest beginnings in the early 1950s, U.S. expenditure on strategic defense (then almost entirely air defense) rose rapidly to $8 billion annually by 1957 but declined sharply thereafter. In 1965 U.S. spending on research and development (R&D) and procurement rose again, reaching $6 billion a year ($1 billion for air defense, $5 billion for missile defense) by 1971. After the ABM Treaty was signed in 1972, spending declined. With the announcement of SDI, spending once again increased, reaching almost $4 billion in 1987. The U.S. pattern has thus been erratic, reflecting decisions in various administrations to react to Soviet developments and perceived opportunities (Figures 1 and 2).

In contrast, the Soviets have shown a persistent interest in strategic defense, and their investments in both research and deployment have reflected this. In fact, Soviet expenditures on strategic defenses are roughly comparable to expenditures on offensive systems. Of their five military

Fig. 1. U.S. Missile Defense: R&D and Procurement (in $1986 billions)

Fig. 2. U.S. Air Defense: R&D and Procurement (in $1986 billions)

commands, the Soviets devote the third ranking one—the Protivovozdushnaya Oborona Strany (PVO Strany, or national air defense forces)—exclusively to air and ballistic missile defense. The PVO Strany contains 635,000 military personnel, almost as large a complement as the entire U.S. Air Force. A comparable air-defense system (including the cost of developing new systems) would cost the United States about $24 billion annually. Given that the Soviets have maintained such an extensive air and missile defense for at least the past ten years, it is reasonable to assume that they have been spending roughly the same proportion of their gross national product (GNP) on these defenses over that ten-year period. Meanwhile, the United States has spent only token amounts of the defense budget on air defense (Figure 2) and little on BMD after the installation at Grand Forks, North Dakota, was decommissioned in 1975. On air defense alone, the U.S.S.R. appears to have spent five times more a year than the United States on all forms of strategic defense for at least the past ten years.

In addition to building and maintaining an elaborate nationwide air defense, the U.S.S.R. also maintains an ABM system designed to protect Moscow and also pursues research on other potential BMD technologies. It initiated a program to develop an ABM system in the late 1950s, shortly after the United States began developing an ICBM. In the 1960s systems believed to have an ABM capability were erected at Leningrad (Griffon), and Moscow (Galosh) (Figure 3). A system was also built at Tallinn, Estonia, but U.S. analysts had differing assessments of its purpose. CIA analysts, supported by their counterparts in the U.S. Navy and the State Department, maintained that the installation was for air defense alone. Analysts employed by the army, the air force, and the Defense Intelligence Agency contended that it was the beginning of an effort to upgrade air defenses against ballistic missiles. Although CIA Director John McCone endorsed his agency's interpretation and the second interpretation was duly recorded in the national intelligence estimate,^[2]    the system at Tallinn was not considered to have BMD capabilities at the time the ABM Treaty was negotiated in 1972. After the treaty was signed, the Moscow installation was the only one to remain intact; it was recently improved with the installation of new silo-based missiles and better radar. The Soviets have also pursued an active research program aimed at investigating directed-energy and other beam weapons. Such an effort in the United States would have cost some $500 billion.

Actual U.S. expenditures over the same period—since the end of World War II—have been considerably lower, perhaps on the order of

Fig. 3. Estimated Soviet Missile Defense Expenditures (in $ 1986 billions)

Fig. 4. Cost of Soviet Air Defense and U.S. Offensive Response (in $ 1986 billions)

$100 to $120 billion. This calculation does not account for improvements in offensive forces, many of which would probably have been made in any case. But certain key technologies—notably the MIRVed missile, the B-1 and Stealth bombers, and the various standoff missiles (such as the ALCM)—were developed primarily in order to assure a continued capability to penetrate Soviet defenses. These offensive innovations have cost roughly $100 billion (Figure 4).

As a consequence, the U.S.S.R. is not significantly better defended against a massive nuclear attack than it would have been had it not invested the equivalent of $500 billion on defenses. Similarly, the United States has not built any adequate defenses for its own territory—although, by spending about $200 billion, it has at least managed to keep abreast of Soviet efforts. The Soviets have thus been prevented from gaining any military advantage, even though they have made larger investments. The U.S. force structure has been modernized and reconfigured, and the total megatonnage in the U.S. arsenal has been reduced in order to assure penetration of Soviet air defenses. U.S. military authorities are thus confident that they can overcome Soviet defenses, even though the U.S.S.R. has outspent the United States by a ratio of five to one, accounting only for expenditures for defense on the one side and offensive modernization on the other (see Figure 4). As former secretary of defense Robert S. McNamara has noted, U.S. experts generally agree that "the billions of dollars the Soviets have spent on air defense in the past two decades have been largely wasted." He also has pointed out that a CIA analyst testified in 1985 that, "against a combined attack of penetrating bombers and cruise missiles, Soviet air defenses during the next ten years probably would not be capable of inflicting sufficient losses to prevent large-scale damage to the U.S.S.R."^[3]    At best, the Soviet ABM defenses provide limited protection to the area surrounding Moscow; otherwise, most of the Soviet Union is unprotected.

Moreover, until SDI, Soviet persistence in deploying and upgrading defenses kept the competition alive and also promoted U.S. interest in anti-satellite systems. Had the U.S.S.R. desisted, the United States would have spent even less on defenses and strategic modernization. Initially reluctant to develop ASATs, the United States preferred to keep its own increasingly important space satellites invulnerable rather than to encourage the Soviet Union to develop a capacity to interfere with them. But each time the Soviets tested an ASAT, impetus was added to corresponding U.S. programs. Recently, the two sides seem to have reversed

positions. During the Reagan administration the United States attempted to develop strategic defenses and ASATs. Under Gorbachev, the Soviets appear interested in preventing further BMD deployments and in obtaining an agreement to ban the development of ASATs, although they, too, continue to invest heavily in defensive research. So far, the futility of earlier phases in this competition has not inhibited either superpower from pursuing the elusive goal of defending against a nuclear attack. A review of the lessons of this futile competition is thus especially relevant to any discussion of SDI.

The United States' Defensive Effort From The 1950s To 1975

The United States' first effort to deploy strategic defenses came in response to a quick series of unwelcome technical surprises. The Soviets detonated their first A-bomb in 1949, followed in 1955 with the explosion of the first full-size H-bomb. A year later the first long-range Soviet bombers appeared—the so-called Bears and Bisons. The United States responded with efforts to construct a continental air-defense system; shelter and evacuation options were also evaluated. By the late 1950s the United States was putting in place extensive deployments of surface-to-air missiles (SAMs) and interceptor aircraft, all backed up by several lines of warning radars. The U.S. Air Force (with fighter interceptors and ground-based radars), the U.S. Navy (with picket ships), and the U.S. Army (with anti-aircraft guns and missiles) were to coordinate their efforts with the help of the Canadian armed forces. To provide the necessary command, control, communications, and intelligence (C³ I) for these systems, the United States planned to install a complex system called SAGE, an acronym for "semi-automatic ground environment." The essential core of SAGE was to consist of a few—perhaps six—complexes housing large, powerful computers. Data from the various sensors would be analyzed by these computers and used to direct the interceptors—aircraft and SAMs. In 1957 the bilateral U.S.-Canadian North American Air (now Aerospace) Defense Command (NORAD) was created to pull all the pieces together.

By 1960 U.S. defense analysts had conceded that the task of defending the country against nuclear attack was impossible: the Soviets had successfully developed a first-generation ICBM, many hundreds of which, it was estimated, would soon be deployed. Eventually, perhaps,

thousands would be deployed. With only a handful of highly vulnerable SAGE centers responsible for the defense of North America, it seemed likely that they would be among the first targets for a missile attack. Soviet aircraft would then essentially have unobstructed access to targets in the continental United States. The problem appeared so insoluble that U.S. policymakers in effect abandoned air defense at the very inception of the missile era. At its peak, in 1957, U.S. spending on air defenses reached more than $8 billion (again in 1986 dollars). It had dropped to a small fraction of that amount by 1962, and it has fallen further since. The United States now has no SAMs defending either civil or military targets. Only about three hundred interceptor aircraft are deployed, most of which are operated by the Air National Guard. Early warning of air attacks from the north continues to be provided by the Distant Early Warning (DEW) Line designed in the early 1950s, as well as by an old Alaskan radar network and the Pinetree Line—a chain of twenty-four long-range surveillance and height-finder radars stretched across southern Canada—but there are significant gaps in the coverage. Improved radar systems have been under development, but no new deployments are being made except for the replacement of older, mechanically steered radars by electronically steered phased-array radars (PARs) in Alaska, England, and Greenland. E-3A AWACs aircraft have been assigned to NORAD, but all dedicated SAMs have been phased out and no new interceptor aircraft have been assigned to NORAD.^[4]   

Early in the Eisenhower administration, and long before Sputnik first orbited in 1957, many of the highest defense authorities became firmly convinced that the Soviets were engaged in a major effort to develop very long range ballistic missiles, including some capable of intercontinental flight. The U.S. response was to initiate two distinct programs; the first was to match and surpass the expected Soviet achievements, and the other was to find ways to directly counter the Soviet threat. In accord with the first objective, the United States initiated five "highest priority" programs on long-range missiles by 1955: Atlas, Titan, Thor, Jupiter, and Polaris. The second program involved a number of projects, too, including the army's Nike-Zeus; the air force's Ballistic Missile Early Warning System (BMEWS) and satellite early-warning systems. A little later, some other projects commenced under the aegis of the Advanced Research Projects Agency (ARPA), now called the Defense Advanced Projects Research Agency (DARPA).

Nike-Zeus was a ground-based terminal missile defense system consisting

of a large, powerful rocket armed with a megaton-class nuclear warhead, along with radars and computers capable of detecting and tracking the incoming warhead and steering the interceptor rocket to its target high in the atmosphere. The very large kill-radius of a nuclear weapon was believed necessary to make up for the imprecision of the early systems. At Bell Laboratories, however, where the transistor was invented in 1948, the new technology had been used to create a much improved high-speed data-processing system for tracking incoming warheads and guiding interception. Overall, the Nike-Zeus system was regarded as a logical successor to the earlier Nike-Ajax and Nike-Hercules anti-aircraft missiles, also developed by the same army agencies. By 1958 the program had advanced far enough for the army to propose near-term deployment of the Zeus ABM system. But the proposal was formally rejected in 1959 as technologically premature. It had already become evident, even in 1959, that decoys and other countermeasures would pose insurmountable challenges to the Nike-Zeus as it was then configured.

These difficulties were thoroughly exposed in a series of reviews, outside and inside government, in the executive and in Congress, over a two-year period.^[5]    A 1957 study by the Rand Corporation (a defense research organization which then had close ties to the air force) pointed out a number of problems with Nike-Zeus. For instance, the ABM radar might not be able to identify an incoming warhead if the warhead were accompanied by other objects—decoys, sections of the booster rocket, or "chaff" (small metal strips designed during World War II to confuse radar). The radar might be subject to blackout owing to natural phenomena such as the aurora borealis, or to deliberate interference by electronic jamming and nuclear detonations in the vicinity of the attack. An internal DOD study came to similar conclusions. It noted that penetration aids, including not only decoys but also multiple warheads with small radar cross sections, were a distinct practical threat to Nike-Zeus. The Rand study also estimated that the estimated kill-probability of a single Nike-Zeus interceptor would be so low that ten to twenty ABMs would have to be fired at each incoming warhead to achieve an acceptable rate of interception. One ABM battery, even if it comprised fifty to one hundred individual missiles, would therefore be able to defend only a small area, obtaining a high rate of reliability against only a few incoming missiles. An enormous number of ABM batteries would therefore be needed to provide a population defense. And even such a thick defensive array could not prevent detonations just beyond the range of

the ABMs—then about twenty miles—which would still cause great damage.^[6]    As for the idea of using Nike-Zeus to defend ballistic missiles rather than civilians, the study argued that hardening, dispersal, and increased deployment, for example, could each yield similar results at a lower cost—a foreshadowing of the criticism voiced a decade later about limited ABM deployment. Added to these technical considerations was the policy adopted by the Eisenhower administration of relying on the threat of "massive retaliation" with nuclear weapons. The technical and policy drawbacks were too numerous: the administration was not eager to embark on an expensive program to deploy Nike-Zeus.

The army did not relent: Three of its senior generals, Chief of Staff Maxwell Taylor, R&D Director James Gavin, and the chief of the Red-stone Arsenal, H. N. Toftoy, presented a proposal for Nike-Zeus deployment that would have cost $6 to $7 billion to be operational in 1961. A paper prepared for the Joint Chiefs of Staff echoed the criticisms in the Rand study. It concluded that the system was not sufficiently advanced to warrant such a level of expenditure and criticized its "Maginot line" thinking. Secretary of Defense Neil McElroy concurred: "There is a great deal we need to know," he observed, "before there can be any such program."^[7]   

Undaunted, the army continued to argue for deployment of Nike-Zeus. McElroy instituted a further review, appointing a special panel to advise him on an army proposal for a large-scale deployment to cost between $10 and $20 billion, well above the earlier estimate. The panel produced a split recommendation with two of the three members calling for a much smaller program, and the third (York) opposing any deployment as premature. When the Joint Chiefs of Staff and the President's Science Advisory Committee (PSAC) also recommended against deployment, Eisenhower rejected the proposal but authorized continuing R&D at the same high level as before—about $500 million per year—with special emphasis on efforts to cope with potential countermeasures.

Disappointed but still determined, the army took its case to Congress, where new hearings were held in 1959. The Army spokesmen tried a new tack with Congress, arguing that decisions to deploy other systems (such as the air force's Atlas and the navy's Polaris) had been made while they still faced the same uncertainties as Nike-Zeus. Although the chairman of the House Armed Services Committee, Carl Vinson, was sympathetic to the army's proposal for a crash program to deploy Nike-Zeus, the committee finally concluded, after hearing from other witnesses, that the system was vulnerable to countermeasures; a

competing air force system, called "Wizard," was considered more promising. McElroy himself testified that according to the best scientific opinion, the system was not far enough along to warrant deployment. This view, he stressed, was a technical assessment, not one based on budgetary considerations. As a result, enthusiasm in Congress waned, and the project remained in an R&D mode.^[8]   

At about the same time that the Nike-Zeus program was initiated, two large-scale development programs for providing early-warning of missile attack were also undertaken. One was the Ballistic Missile Early Warning System (BMEWS), consisting of huge radars capable of detecting ballistic missile warheads or "reentry vehicles" (RVs) at distances on the order of a thousand miles. Three such systems were eventually deployed as far forward as possible: central Alaska; Thule, Greenland; and Fylingdales Moors, England. They are still in place, although efforts are under way to modernize them.

A statellite-based system named Midas was the other early-warning system undertaken as part of the United States' first response to Soviet ICBMs. Consisting of an infrared detector system mounted on a satellite in high orbit, it was capable of detecting rocket plumes produced by ballistic missiles during the launch phase. The original project was part of a large satellite-applications package contracted by the air force to the Lockheed Corporation in 1956, more than a year before Sputnik I . The project encountered a number of technical difficulties in the early phases of its development, but these were eventually overcome and the system has for years formed an essential part of U.S. early-warning capability. In recent times, it has been known as the DSP (for Defense Support Program) or SEWS (for Satellite Early Warning System).

In early 1958 ARPA initiated Project Defender, a collection of research and development projects relevant to ballistic missile defense but more advanced or speculative than those then in the Zeus program. A number of ideas first explored under this rubric eventually were widely applied in air and missile defenses as well as in other military and civil uses. The electronically steerable phased-array radars are an especially notable example.

In addition to these high-priority programs, all of which were solidly based in the technology of the time, more fanciful ideas were studied. Ballistic Missile Boost Intercept (BAMBI) and Space Detection and Tracking Systems (SPADATS) were two such programs. Both involved space-based anti-missile systems consisting of many small interceptors. In the case of BAMBI, the interceptors were all to be independently orbiting

satellites; in that of SPADATS, they were to be mounted in clusters on a larger "battle station." Each of the small interceptors was to be rocket-powered and guided to its target by an infrared homing system. Each was designed to destroy an attacking missile during boost phase by colliding with it at an extremely high differential velocity. These early ideas were remarkably similar in overall design and purpose to those promoted in the early 1980s by the High Frontier group. During the late 1950s, however, these projects did not advance beyond the study-only phase and were eventually dropped from serious consideration. Beam weapons—both particle beams and lasers—for missile interception during the late, or terminal, phases of flight, were also being considered in the defense science community. They were extensively studied by ARPA and, under ARPA sponsorship, by the Jasons—a summer study-group of scientists active in DOD-supported defense research. As in the case of the space-based kinetic-energy kill systems, these programs never went beyond the study-only phase.

Development of the Nike-Zeus system continued throughout the early 1960s. There were improvements in rocket propulsion, warhead characteristics, and radar design; in addition, means were proposed for coping with at least the simpler kinds of decoys. By increasing the time between target acquisition and ABM launch, the defenders could take advantage of "atmospheric sorting," whereby lighter decoys would be slowed by friction in the upper atmosphere, enabling relatively easy discrimination of targets from decoys. Even so, the defense authorities continued to conclude that deployment remained technologically premature in view of the serious problems posed by more sophisticated counter-measures and "saturation" (attacks too large for the defense to counter). Other developments also clouded the picture. Although two 1958 nuclear-test explosions in the upper atmosphere near Johnston Island in the Pacific raised hopes among advocates (preliminary data indicated that radiation effects might destroy incoming RVs), subsequent analysis showed that RVs could still get through. The same tests also showed that high-altitude nuclear explosions created background noise that would affect radar reception. Although Nike-Zeus was designed to operate below the range at which these effects would be felt, offensive employment of atmospheric nuclear detonations might prevent defenders from extending the range of radar tracking.

Despite all the doubts, however, Secretary of Defense McNamara ordered the priority development of a BMD system designated "Nike X." This was to include a large, hardened, electronically steered radar

and the high-performance Sprint interceptor armed with a small warhead and a tracking radar. The system was to be capable of tracking and discriminating among thousands of targets. Once again, studies showed that the objectives appeared unrealistic in view of the opportunities available to the offense; the cost, especially of a new large radar installation, was also prohibitively high. The technologists therefore proposed construction of long-range PARs to serve many installations, coupled with an on-site missile defense radar. As in the Eisenhower years, deterrence policy worked against defensive deployment. McNamara's commitment to deterrence by assured destruction, like the Eisenhower-Dulles adherence to massive retaliation, was inconsistent with Soviet deployment of ABMs. The Soviet Union was sure to follow suit if the United States deployed defenses first. For both technical and policy reasons, options other than territorial defense began to receive more serious consideration.^[9]   

The political climate surrounding ABM deployment changed in 1967. Lyndon Johnson was still seriously thinking of running for reelection in 1968, and he had become sensitive to the renewed political pressures in favor of deployment. Johnson feared that he would be faced with charges of an "ABM gap," analogous to the "missile gap" charge he and John F. Kennedy had hurled at the Republicans in 1960. At the Glassboro, New Jersey, summit in 1967, McNamara tried to defuse the issue by persuading Soviet Premier Alexei Kosygin that both sides would be better off if they could mutually agree to refrain from developing and deploying ABMs. McNamara has recounted the exchange vividly:

I said: "Mr. Prime Minister, you must understand that the proper U.S. response to your Soviet ABM system is an expansion of our offensive force. If we had the right number of offensive weapons to maintain a deterrent before you put your defenses in, then to maintain the same degree of deterrence, in the face of your defense, we must strengthen our offense. Deployment of a Soviet ABM system will lead to an escalation of the arms race. That's not good for either one of us."

Kosygin was furious. The blood rushed to his face, he pounded on the table, and he said: "Defense is moral; offense is immoral!" That was essentially the end of the discussion. The Soviet Union was by no means ready at that time to discuss an agreement banning defensive systems.^[10]   

After that meeting U.S. policymakers from the president down agreed that the United States had to expand its offensive forces to offset projected Soviet defensive deployments, which at the time seemed likely to be widespread. A decision was thus taken to proceed with development

of MIRVs. The decision on deployment was deferred until further efforts had been made to persuade the Soviets to desist in their deployment of an ABM system. If such persuasion succeeded, the United States was prepared to scrap the MIRV program. First, it would no longer be justified, and second, the Soviets were bound to develop their own MIRVs; there was no need to increase the number of warheads on both sides.

But Johnson had also decided that the United States must deploy ABMs of its own. McNamara reluctantly set about implementing the decision. In an extraordinary speech in San Francisco in 1967, he first presented the arguments against a large-scale, thick defense of the nation as a whole against a determined Soviet missile attack, but then ended with a rationalization for proceeding with a "thin" deployment that would be capable of coping with attacks by a smaller power (i.e., China) or with an accidental Soviet launch of a single missile. The system would use components developed in the Nike X program: the short-range Sprint and the long-range Spartan interceptors, and both PARs and missile-site radars. Even while announcing plans for this light "Chinese-oriented ABM deployment," McNamara warned against efforts to expand it to a full-fledged deployment for defense against Soviet attack. The danger, he noted, was psychological as well as physical:

There is a kind of mad momentum intrinsic to the development of all new nuclear weaponry. If a weapon system works—and works well—there is strong pressure from many directions to procure and deploy the weapon out of all proportion to the prudent level required.

The danger in deploying this relatively light and reliable Chinese-oriented ABM system is going to be that pressures will develop to expand it into a heavy Soviet-oriented ABM system.

We must resist that temptation firmly—not because we can for a moment afford to relax our vigilance against a possible Soviet first strike—but precisely because our greatest deterrent against such a strike is not a massive, costly, but highly penetrable ABM shield, but rather a fully credible offensive assured destruction capability.

The so-called heavy ABM shield—at the present state of technology—would be no adequate shield at all against a Soviet attack, but rather a strong inducement for the Soviets to vastly increase their own offensive forces. That, as I have pointed out, would make it necessary for us to respond in turn—and so the arms race would rush hopelessly on to no sensible purpose on either side.^[11]   

As part of the process for carrying out the Johnson administration's plan, the U.S. Army began to hold public hearings in a number of cities, including Seattle, Chicago, and Boston, in preparation for deployments

nearby. These plans and hearings produced a reaction that surprised the army leadership and other national authorities. Peace activists and critics of ABM deployment successfully organized campaigns against "bombs in the backyard" and forcefully brought their opposition to the attention of their legislative representatives. Some of the scientists who in the 1980s were to campaign against SDI cut their political teeth on the issue of ABM deployment. Their efforts succeeded in dramatizing the issue and provoking concern, especially in the communities where the facilities were to be located. Ad hoc coalitions of citizens for and against ABM deployment pressed their cases in public.^[12]   

Before the issue could be resolved, Richard Nixon became president and decided to continue with the "thin" deployment authorized by Johnson as the Sentinel system. Political opposition remained strong, however, because of local issues, continuing doubts about technical feasibility, and more general strategic concerns, including the role ABM deployment played in the overall arms race. Largely in response to this opposition, Nixon and his advisors decided to change the program objectives from defending the country as a whole against a minor missile attack to defending only U.S. retaliatory forces, particularly ICBMs, against a major missile attack. The equipment for doing so remained basically the same but the location and purpose became radically different; the project was renamed "Safeguard." The new objectives were to defend land-based retaliatory forces against a Soviet threat while preserving a "growth option" to provide an area defense against a smaller "n th country" threat. Twelve Safeguard sites were planned, but construction was initiated at only two, Malmstrom, Montana, and Grand Forks, North Dakota.

Rather than placating the opposition, this apparently opportunistic behavior on the part of the administration only encouraged it. Extensive congressional hearings on Safeguard were held in 1969 and 1970, and expert members of the defense establishment, as well as representatives of public-interest groups, testified against deployment (York among them). A number of important Republican senators—Cooper (Kentucky), Brooke (Massachusetts), and Case (New Jersey)—assumed leading roles in opposing the administration's plan. When it came to a final vote to deploy the first units of ABMs, the Senate tied 50 to 50; the vote of Vice-President Spiro T. Agnew broke the tie. The proponents of the ABM had won the battle, but ABM opponents were about to win the war: with such a razor-thin margin of support, so controversial a program simply could not proceed further along the lines its promoters had intended.

While the ABM deployment program was going through this rocky period, consideration was being given to the proposal of a treaty banning or limiting ABMs as part of an overall scheme to limit strategic weapons. The idea of limiting defensive systems arose in defense circles early in the Johnson administration and was broached to the Soviets at the Glassboro summit in 1967. The Soviet rejection of the proposal was followed by the dispatch of Soviet troops to stifle political change in Czechoslovakia in 1968, preventing further high-level exploration of the issue at the time. But Nixon revived the idea in 1969, at least partly because of the widespread opposition to ABM deployment that had developed independently of any consideration of a bilateral treaty.

The revival of interest in a treaty banning ABMs provoked a heated debate. Those who favored a ban on the weapons made several contentions: ABMs, as then conceived, would not work; they would be destabilizing; and they would cost too much. Those in favor of ABMs argued that they would work well enough to make them worthwhile; that they would, on the contrary, be stabilizing, especially in a crisis (by removing any temptation to launch a surprise attack); and that the United States must not put "the budget ahead of survival."

Perhaps the most important argument about technical feasibility involved the problem of countermeasures. Many specialists agreed that the effort to build defenses would involve an endless contest in which the offense would always be one jump ahead. In addition, no defense system could even be tested as a whole and in a realistic manner. This was a decisive fact for many experts. Individual components of the system could be tested against U.S. offensive devices on a one-on-one basis, but such procedures could never provide the information necessary for judging the utility of an ABM system against a massive surprise attack. In addition, other crucial questions, such as the ability of ABM radars to cope with the blinding effects even of defensive explosions, were never satisfactorily resolved. Those who favored proceeding with ABM acknowledged the seriousness of at least some of these problems but argued that the only way to resolve them was to mount a major program in the field, including at least enough deployment to provide some "real world" experience.

The arguments regarding destabilization took two quite different forms. The first one, focusing on the stability of the arms race, was the simplest. If one side builds a defense, it was said, the other will respond by expanding its offense, given that saturation and exhaustion of the defenses are the ultimate offensive countermeasures. This argument was supported by the fact that the United States was even then considering

the deployment of MIRVed warheads as the best answer to the initial Soviet ABM deployment. Proponents of ABM countered that the Soviets could not readily respond by expanding their force, so long as ABM could be made cheaply enough, or, more technically, "cost-effective at the margin." The second argument involved the behavior of leadership in crises. Opponents of ABM deployment placed special emphasis on the easy and confident calculability of the existing situation, in which any attacker could be assured that he was engaging in a suicidal act. They argued that the deployment of ABMs would introduce the kind of uncertainties—and perhaps also a false confidence—that could lead to rash acts. Those favoring ABM emphasized that "active defenses" could help to assure the survival of military authorities and retaliatory forces and would thus reinforce deterrence. No clear consensus emerged on the strategic issues. Both sides could cite many acknowledged experts on strategy who supported their position.

The technical issues produced no such ambiguity: a clear majority of experts concluded that ABM as then conceived would not work in any useful sense of the word. In the end, doubts about the technical merits of the system carried the day. A formal limitation on ABM deployment was initiated.

The Soviets were eventually persuaded that a ban on ABMs could provide a good place to begin negotiations on controlling strategic weapons as a whole. Discussions to that end were started in late 1969, the first year of the Nixon administration, and came to fruition in 1972. The resulting treaty limited ABM deployment to two sites in each country, each site in turn being limited to one hundred ABM missiles. It was further agreed that only one such site could be near the national capital, with the other located solely for protecting retaliatory forces, more than 1300 km from the national capital. (This agreement was later modified to permit a hundred launchers, each carrying a single warhead, at one site only, at either location, in each country.)

The upshot of all these twists and turns for the United States was the brief deployment of ABMs at a Minuteman missile base at Grand Forks, North Dakota. The Grand Forks system was declared to have achieved "initial operational capability" (IOC) in March 1975 but was terminated by Congress later that year. Since then, the United States has not deployed ABMs anywhere, but the Defense Department continues to support R&D designed to explore the possibilities further.

Until the birth of SDI, U.S. research was mainly focused on the improvement of "site defense" for protecting Minuteman missiles or other

high-value targets more effectively and at lower cost. ARPA and the Army Ballistic Missile Advanced Technology Program also studied a broad range of technologies relevant to BMD. In several areas, these efforts led directly to programs now being further developed under SDI. These included

the High-Acceleration Boost Experiment (HIBEX) program that developed the basis for a more advanced interceptor now being considered, the Designating Optical Tracker (DOT) program that provided the basis for much of exoatmospheric Long Wave Length Infrared (LWIR) sensing and discrimination knowledge, the Homing Overlay Experiment (HOE) that is developing the non-nuclear-kill-intercept technology, various directed-energy studies that evaluated particle-beam and high-energy laser BMD system concepts, and numerous other missile, discrimination, radar, optics, and data-processing technology programs related to U.S. BMD concepts.

By 1983, when President Reagan announced SDI, these programs had produced an "on the shelf" site-defense technology; its radars and interceptors were small enough to be deployed in a mobile-basing mode along with the new MX launchers and were capable of intercepting incoming warheads even at very low altitudes.^[13]    If any of the mobile-basing schemes proposed for MX had been adopted under Carter or in the early years of the Reagan administration, deployment of a site defense (as allowed by the ABM Treaty) would most probably have been considered. Whether it would have been deployed, in view of the protection already afforded by the mobility of the MX, is more doubtful.

Spending on the ABM program followed a course that might be expected, given such a turbulent situation. Starting from scratch in 1956, the Zeus R&D program reached a spending rate (in 1986 dollars) of almost $2 billion in 1960. In 1965 R&D spending topped out at $3 billion, but total spending continued to climb on up to about $5 billion in 1970, with procurement of equipment for the Grand Forks deployment then taking the lion's share. From then on, spending dropped sharply, falling back to only about $1 billion per year in the period following the termination of the deployment in 1975.

The Soviet Effort In Defensive Systems

Western understanding of Soviet intentions is often beset by uncertainties, and the case of strategic defense is no exception. Are the Soviets pursuing some long-term goal of achieving an effective defense in order

to break out of the ABM Treaty? Or are they simply pursuing allowable defensive efforts to limit damage from a nuclear attack and doing research so as not to be put at a disadvantage if the United States should achieve some technological breakthroughs? Are they content to have SAMs functioning as anti-aircraft weapons, or are they secretly attempting to render them effective against ICBMs as well? Are they using the loopholes of the treaty that allow development of anti-tactical weapons and ASATs as efforts to develop technologies that will permit broader ballistic missile defense than is foreseen in the treaty? All that can be established beyond dispute is that for forty years the Soviets have pursued a large and comprehensive program in passive and active defenses, the total size of which has grown steadily, despite the ABM Treaty, and which has been supported by formidable and broadly based research efforts. So far as can be ascertained, however, the Soviet Union has not exceeded the bounds on testing and development set by the ABM Treaty. And there is good reason to believe that because it decided to agree to a limitation on ABMs, the Soviet civil and military leadership has adopted a strategy of retaliatory deterrence essentially the same as that previously adopted by the United States.

The Soviet program for BMD research was originally established by Joseph Stalin in the immediate aftermath of World War II. Stalin is thought to have been influenced by several considerations: the damage inflicted on the Soviet Union by the Luftwaffe, Britain's vulnerability to the German V-1 and V-2 weapons, and the knowledge that Soviet technologists, with the help of captured German rocket scientists and engineers, were working on the development of ICBMs.^[14]    At the Twenty-second Congress of the Communist party of the Soviet Union, in October 1961, Defense Minister Rodion Malinovsky announced that "the problem of destroying enemy missiles in flight has been successfully resolved," and in July 1962 Premier Nikita Khrushchev boasted that Soviet missile forces were so accurate that they could "hit a fly in space."^[15]   

Although these claims were wildly inflated, the Soviets have invested heavily not only in research on strategic defense but also on actual deployments—mainly, however, for defense against bomber attack rater than ballistic missiles. The Soviets apparently believe that although air defense can be "damage-limiting," a territorial defense against ICBMs is neither feasible nor affordable.

The Soviets maintain the world's most extensive missile early-warning system. It includes a satellite network for launch detection, over-the-horizon radars, and a series of large phased-array (capable of being electronically steered) radars (LPARs) on the periphery of the country (and

inland, at Krasnoyarsk, in apparent violation of Article V1-b of the ABM Treaty, which requires that each party locate such radars only "along the periphery of its national territory and oriented outward"). The satellite system is capable of providing about thirty minutes warning of any U.S. ICBM launch and of determining the general area of its origin. The two over-the-horizon radars could provide the same time warning, but with less precision and certainty than that provided by the satellite network. In addition, the Soviets maintain eleven large "Henhouse" detection and tracking radars at six locations on the periphery. These can distinguish the size of an attack, confirm the warning from satellites and over-the-horizon radars, and provide target tracking in support of deployed ABMs. The Soviets are currently constructing six new LPARs, including the controversial Krasnoyarsk installation in central Siberia. According to the DOD, these systems "duplicate or supplement" the coverage of the "Henhouse" network, "but with greatly enhanced capability."^[16]   

An ABM system has been deployed around Moscow, as allowed under the ABM Treaty, and has been undergoing improvements since 1980. The original single-layer system included sixty-four reloadable aboveground launchers at four complexes, collectively called the Galosh system. Each complex was served by six mechanically steered "Try Add" guidance and engagement radars and all were assisted by the "Doghouse" and "Cathouse" target-tracking radars south of Moscow, which are believed to provide battle management for the defense of Moscow. The system is now being enlarged to accommodate one hundred launchers, the maximum allowable under the ABM Treaty. When completed, it will provide two layers of defense, one composed of silo-based, long-range, modernized Galosh interceptors (designated by the United States as SH-04 or ABM X-3) designed to engage targets outside the atmosphere; the other using silo-based, high-acceleration Gazelle interceptors (or SH-08) to engage targets within the atmosphere. Thus, the Soviet system will resemble the United States' combination of Spartan and Sprint missiles. It will also have associated engagement and guidance radars and a new large radar at Pushkino designed to control ABM engagements. The silo-based Gazelle launchers may be reloadable, and the system may have become fully operational in 1987.^[17]    Because of the range of the Galosh, the system provides some degree of regional protection. The "footprint" of the missiles extends over several thousand square miles of Soviet territory, an area that includes three hundred ICBMs.^[18]   

The new LPARs could supplement older radars by providing early-warning

and pointing data for the new Moscow ABM system. All the new LPARS will become operational in the late 1980s and will make up a comprehensive network. The CIA estimates that this system will provide the Soviets with "a much-improved capability for ballistic missile early-warning, attack assessment, and targeting" and will provide battle-management support for a widespread ABM system.^[19]    In August 1986 two additional LPARs were discovered to be under construction in the western U.S.S.R. The United States has complained that the radar under construction at Krasnoyarsk is in violation of the ABM Treaty. This facility may or may not be intended to serve for eventual countrywide battle management in an ABM system. The Krasnoyarsk radar is said by the DOD to close a gap in a combined radar early-warning and tracking network: "Together, this radar and the five others like it form an arc of coverage from the Kola Peninsula in the northwest, around Siberia, to the Caucasus in the southwest." Its orientation, the DOD contends, "indicates it is for ballistic missile detection and tracking"—not space-object tracking as claimed by the Soviets.^[20]    Indeed, in view of the radar's capacities and orientation, it is most unlikely that it was intended for space tracking. Conceivably, the installation is intended to fill the gap in the early-warning system that could not easily be filled by the construction of peripheral radars, perhaps owing to soil conditions and the remoteness of the sites. Or, as Michael MccGwire has speculated, the radar might have been placed at Krasnoyarsk to detect an attack from Trident submarines stationed in the Bering Sea or the Gulf of Alaska—a threat not anticipated when the Soviets agreed to the limitation on placement of LPARS in the ABM Treaty—and to place the installation within a defensible perimeter in the event of an invasion through Xinjiang in northwest China.^[21]   

Soviet air defense is said by the Pentagon to have "excellent" capabilities against aircraft flying at medium and high altitudes, but only "marginal" capabilities against low-flying aircraft. These facilities are undergoing a major overhaul, which will result in the fielding of an integrated system more capable at low altitudes. This system will include the use of the I1-76 Mainstay airborne warning and control system (AWACS), similar to that developed by the United States, in addition to more than one hundred MiG 31/Foxhound interceptors equipped with look-down shoot-down radar and multiple-target engagement capability air-to-air missiles.^[22]   

The Soviets have put a very substantial effort into the development of ground-based air defenses and fighter interceptors: thirteen different

surface-to-air missiles (SAMs) have been developed, each designed to counter a particular type of threat. These SAMs include the latest deployed system, the SA-10, and another under development, the SA-X-12, which may have a capability against tactical ballistic missiles such as the U.S. Lance and Pershing I and II as well as aircraft.^[23]    Currently, the Soviets deploy more than 9,000 SAM launchers at 2,100 sites for strategic defense, in addition to 4,600 launchers for tactical SAMs. More than 1,200 fighter interceptors are dedicated to strategic defense, and an additional 2,800 other interceptors are also available. A quarter of the interceptors are MiG-25/Foxbat A/E high-speed interceptors for high-altitude defense. The rest consist of older aircraft (one-third of the force) and two new fighter interceptors, the Su-27 Flanker and the MiG-29 Fulcrum, both of which are designed to be highly maneuverable in air-to-air combat and are equipped with two new air-to-air missiles, one long range, the other short range.^[24]   

To locate and target incoming attacks, the Soviet Union has deployed more than 10,000 radars of various types at about 1,200 sites, providing virtually complete coverage at medium-to-high altitudes over the country and, in some areas, beyond its borders for hundreds of kilometers. The over-the-horizon radars provide warning of the approach of aircraft flying at high altitude. Coverage of low-flying aircraft is concentrated in the western regions and in high-priority areas elsewhere. Since 1983 two new types of air-surveillance radars have begun to be deployed. These assist in providing early warning of cruise missile and bomber attacks and in enhancing air defense electronic warfare capabilities.^[25]    The new Soviet "Pawn Shop" missile guidance radar and "Flat Twin" tracking radar are modular and could be assembled, once mass-produced, at a number of sites within a matter of months. The Reagan administration has complained that these radars are a "potential violation" of the treaty because they fall in the category of mobile ABM systems and components that are specifically banned.^[26]    The usual interpretation of the treaty does not preclude systems of this type.

Of the five SAM systems now operational (designated by the United States as SA-1, -2, -3, -5, -10) and SA-X-12, only the SA-10 seems capable of defending against targets with radar cross sections as small as that of a standard ("nonstealthy") cruise missile. Sixty sites are now operational, and work is under way on at least another thirty. More than half these sites are near Moscow, suggesting that the Soviets have put a high priority on terminal defense of wartime command-and-control systems, as well as of military and key industrial complexes. A mobile

version of the SA-10 is being developed to support theater forces, but it could also enhance the survivability of SAMs used in the Soviet Union for strategic defense.^[27]   

The SAMs and interceptor aircraft are further enhanced by antiaircraft artillery (AAA), more than 11,500 pieces of which are deployed with units at all levels of readiness and in all regions. At battalion and company levels and with nondivisional units, as many as 25,000 shoulder-fired SAMs are stocked. More than 8,100 SAMs and AAA pieces—the largest concentration—are found opposite NATO; more than 4,200 are near the Sino-Soviet border and in other eastern areas of the U.S.S.R.^[28]   

The Soviets have also pursued a variety of measures of passive defense, aiming to protect missiles as well as the party and government leadership, major economic assets, and the general population. Extensive planning has been done for the transition of the economy to a wartime posture. A program has been under way for thirty years to harden command posts and establish survivable communications for military commanders and civilian managers. Commanders and managers at all levels are provided hardened alternate command posts well away from urban centers. This system, comprising 1,500 hardened facilities with special communications, is patterned after similar capabilities provided the armed forces. More than 175,000 key personnel are thought to be provided such protection, in addition to the many deep bunkers and blast shelters in Soviet cities. Vital materials have been stockpiled, many in hardened underground structures. Blast shelters have been built for workforces, and contingency plans have been drawn up for the relocation of factories and equipment.^[29]    ICBM silos, launch facilities, and command-and-control centers have been sufficiently hardened to resist destruction by some U.S. weapons. Means of communication have been made more elaborate, so as to provide redundancy, and have also been hardened to resist the effects of nuclear attack. New, mobile ICBMs, including the road-mobile SS-25 and the rail-mobile SS-24, have also been developed. These new missiles will complicate the attacker's targeting task, especially because these missiles can be hidden in tunnels or in special hardened and camouflaged sites. The Soviets have also developed long-range nuclear-armed submarines comparable to the U.S. Poseidon, which also help to assure the survival of its retaliatory forces in the event of a preemptive attack.

In addition, three Soviet SAMs—the SA-5, SA-10, and SA-X-12—may already have some ABM capability. The SA-5 has been tested in

conjunction with ballistic missile flights but is considered to have, at most, a marginal BMD capability. The SA-10 and SA-X-12, according to the DOD, may have some ability to intercept certain types of U.S. ballistic missiles.^[30]    But all these missiles are likely to be effective only against older-generation SLBM warheads rather than against newer ICBM warheads; the former are generally slower and offer larger radar cross sections. The SA-X-12 might be able to engage U.S. tactical missiles, such as the Lance and Pershing I and II; it has reportedly been tested successfully against a Soviet intermediate-range Scaleboard missile. The SA-X-12 is mobile and could be stored and concealed.

The Soviet high-energy laser research program dates from the 1960s and is said to be much larger than that of the United States. The Defense Department estimated in 1979 that Soviet spending on high-energy lasers was five times that of the United States. The U.S.S.R. has built more than a half-dozen major R&D facilities and test ranges and employs more than ten thousand scientists and engineers in laser development, notably at Sary Shagan. These specialists, who are quite capable, have worked on chemical, gas-dynamic, and electric-discharge lasers; they are pursuing necessary support technologies for laser weapons, such as efficient power sources; and they have the ability to produce high-quality optical components. According to the DOD, the Soviets have already deployed ground-based lasers that could be used to interfere with U.S. satellites and are presently likely to have lasers capable of serving as ASATs.^[31]   

Soviet laser research is thought to be aimed at developing three types of air-defense weapons: for defense of high-value strategic targets in the U.S.S.R., for point defense of ships at sea, and for air defense of theater forces. The DOD claims that the laser intended for strategic defense is already in the prototype stage and could be deployed and operational by the late 1980s, most likely in conjunction with SAMs in a point-defense role. Also under development is an airborne laser that could have such missions as anti-satellite operations, protection of airborne assets, and cruise-missile defense. Soviet researchers are also working on space-based kinetic-energy weapons, ground- and space-based lasers, and particle-beam and radio-frequency weapons. They are reported to believe that such systems hold promise for BMD and for improved conventional defense.^[32]   

Some reports indicate that Soviet ground-based lasers are already available for military use. The ground-based lasers at Sary Shagan are reported to have potential ASAT capabilities against low-flying U.S. satellites.

A U.S. press report has claimed that Soviet ground-based microwaves at a facility in a mountainous area at Dushanbe, in the Tadzhik Republic (where a laser facility is reported to have been built), disabled U.S. photoreconnaissance satellites in low polar orbit on more than one occasion in 1986. The U.S. Air Force Space Command has denied such attacks, but a French commercial satellite photography service has circulated photos of a well-developed facility at the Dushanbe site.^[33]    The German newspaper Bild Zeitung quoted top-secret U.S. and NATO reports of Soviet lasers disabling optics and electronics on U.S. satellites. Others speculate that the Soviets already have the technological capability to conduct electronic warfare against space systems. In view of the Soviets' recent reported work on microwave weapons that generate single pulses with peak powers exceeding one gigawatt and repetitive pulses of more than 100 megawatts, it is also speculated that the Soviets could test a ground-based microwave weapon by the 1990s capable of damaging satellites. (Jamming reconnaissance satellites almost certainly would violate ABM Treaty prohibitions on interfering with "national technical means" of verification. The United States is working on improving the resistance to jamming of satellites by incorporating laser crosslinks, improving satellite autonomy, and developing extremely high frequency [EHF] spread-spectrum and laser heterodyne communications systems.) Senior DOD intelligence officials say the Soviets now possess a "limited operational capability" to blind some U.S. satellites. Others contend that Soviet ground-based DEWs could damage some types of penetration aids and thus indirectly serve as BMD weapons.

Nevertheless, the present Soviet missile-defense capability, even if it were made the basis of a countrywide defense, could not prevent enormous damage from a U.S. nuclear attack, or even from an attack by an adversary with a smaller arsenal. Coupled with Soviet offensive capabilities, however, it can be said to increase uncertainty in the minds of a potential attacker. Soviet offensive forces alone account for considerable uncertainty; the defensive systems add to it. (This is, of course, one of the rationales offered by SDI proponents for building a U.S. defense.) Defense also helps to enhance the prospect that Warsaw Pact forces would prevail in a conventional conflict in Europe. U.S. countermeasures—especially air-breathing systems equipped with "stealth" technology—could defeat the Soviet defenses, but as defenses cause higher rates of attrition, they compel dedication of more weapons, thus tending to nullify the strategic doctrine of "flexible response." Targeting flexibility

is bound to be somewhat constrained by the addition of defensive systems, and damage expectations become less predictable.^[34]   

Why The Different Approaches?

Why have the superpowers pursued such contrasting strategic defense policies? One reason is that the Soviets have to take account of the United States' heavy-bomber threat, whereas until recently the corresponding threat from the U.S.S.R. was much less fearsome. The Soviets have therefore had a greater incentive to develop and deploy air defenses; compared to missile defenses, they are technologically more promising. But these considerations alone cannot account for the broad, persistent, and costly Soviet effort to develop passive and active defenses. Sayre Stevens, a former CIA intelligence analyst, has suggested that the approaches of the two sides reflect differing views of what is strategically valuable.^[35]    The U.S. authorities have been reluctant to deploy defenses that they knew would have only marginal utility. Their Soviet counterparts seem to operate on the assumption that any degradation of an attack has some value. Their conviction in this regard may well be fed by memories of World War II, when the armed forces and the populace suffered gravely because of the total absence of air defenses. (If so, they may be taking too little account of the differences between nuclear and conventional weapons, and between World War II and contemporary delivery systems.) The Moscow ABM defense cannot protect against a massive U.S. attack, but it might protect the capital against an accidental launch, and it might also offer some protection against a "decapitating" attack (one aimed at the national-command authority) or a light attack. The Soviets apparently also count on making continual improvements. By constantly upgrading air defenses and ABMs and providing a more and more effective integrated system for detecting and tracking an attack, they may be hoping to lay the foundations for a much more effective system.

Another factor that may help to account for Soviet behavior is strategic doctrine. Michael MccGwire has argued that until the late 1960s Soviet military planners operated on the belief that if war with the West came, even in the form of conflict in Europe or some other theater, the war would become nuclear and would entail nuclear attacks on Soviet territory.^[36]    This belief was reinforced by the U.S. doctrine of massive retaliation espoused by the Eisenhower administration and the subsequent

NATO doctrine of "flexible response." Accordingly, the Soviets sought to achieve a capacity to fight and win a nuclear war in order to deter a Western attack. Their most critical concern was to minimize the damage a nuclear attack might cause. For this purpose, the Soviets sought both offensive and defensive means. They set out to build an ICBM force capable of launching an effective preemptive strike against U.S. missiles and submarine and bomber bases. To complement the offense, they also set out to pursue both active and passive defenses. Thus, the relatively high priority accorded to strategic defense was a function of the overall conviction that any war with the West would necessarily entail nuclear destruction on Soviet territory. As Stevens points out, "the Soviet approach to the reduction of damage is to use not only the counterforce capability of offensive weapon systems, but [also] air defenses, civil and passive defenses, and ballistic missile defenses. The role of these strategic elements would be to limit the damage to the Soviet Union after a preemptive strike."^[37]    The Soviets, in other words, were under no illusion that defenses could be made superior to offenses; they believed, however, that defenses would have some value against a degraded U.S. retaliatory strike.

In 1967 and 1968, according to MccGwire's analysis, this general strategic assumption began to undergo a profound change. The Soviet authorities seem to have become persuaded that the "correlation of forces" had changed sufficiently owing to a combination of factors—military, political, and economic. As a result, the thinking went, it was no longer inevitable that conflict with the West would necessarily result in a nuclear attack on Soviet territory. They also took account of the change in Western strategic doctrine from massive retaliation to flexible response. A conflict, they reasoned, might be confined to a particular theater, such as central Europe. It was presumably on the basis of this change in Soviet strategic thinking, as well as out of a recognition that the West might exploit its technological superiority, that the Soviets decided it would be in their interest to negotiate limits on defensive and offensive weapons. They were probably also becoming more doubtful about the utility of their defenses, in view of the West's countermeasures. Moreover, both the political and military authorities may have been concerned with shifting defense budget allocations away from strategic forces in favor of building up capabilities for force projection in the Third World.^[38]   

U.S. policy has not precluded the use of nuclear weapons in a preemptive attack or a first strike. But, except for a brief flurry of interest in

building shelters and dispersing industry and population, the prevailing view has been that there can be no effective civil defense against a massive nuclear attack. The United States' effort has been to maximize the survivability of a credible retaliatory force by adopting techniques of passive defense—redundancy, silo-hardening, mobility, and dispersion.

The change of doctrine, reflected in Soviet behavior since the late 1960s, may suggest at least a degree of convergence of interests between the superpowers. In itself, this convergence might seem to promote the possibility of agreement on the limitation of defensive systems. Unfortunately, it has been undercut by another competition—the competition by both sides in the militarization of space.

The Militarization Of Space

Since the launching of the first earth satellites, both superpowers have made determined efforts to make military use of space, despite statements on both sides expressing the hope that space could remain a sanctuary for peaceful activities. In 1958 Eisenhower wrote two letters to Premier Nikolay Bulganin proposing cessation of all military activities in space, including the testing of long-range missiles, conditioned on the establishment of an international system of observation or verification. The Soviet leader rejected the overtures, interpreting them as an effort by the United States to thwart an activity in which, thanks to the success of Sputnik , the Soviets had demonstrated an advantage. Eisenhower may not have foreseen all the military possibilities opened by the development of rocket boosters, but he was even more concerned about the burden on the U.S. taxpayer of the effort to contain the expansiveness of the Soviet Union. To keep a lid on the defense budget, he was interested in constraining the arms race wherever possible. For their part, the successful launching of Sputnik I may have led the Soviets to see space as a venue in which they could quickly and economically compensate for the advantages the United States enjoyed in other areas of military technology, including its stockpile of nuclear weapons.

Even under Eisenhower, however, the United States began to exploit space for military purposes, to an extent over the years hardly less determined than that of the U.S.S.R. Together, both states have put more than two thousand military payloads into orbit since the early 1960s—two-thirds of the total number of satellites launched into space.^[39]    The U.S. military budget for space in FY1984 was $10.5 billion, half the total budget for all space activities. The Soviet budget is probably at

least as large, taking account of the difficulty of comparing costs in the two systems.

As a result, both countries have become increasingly dependent on space satellites for military purposes. But thus far, these purposes have been in the nature of support for terrestrial activities: intelligence gathering, communication, electronic intelligence, the monitoring of military testing, and ocean reconnaissance for tracking surface shipping. Increasingly, space is also being used for navigation, for early warning of nuclear attack, for detection of nuclear explosions, for the collection of meteorological data (useful for directing photographic satellites away from cloud cover, as well as for military operations), and for obtaining geodetic data (useful for improving missile accuracy) and information about shifting magnetic fields.

So far, neither side has deployed weapons in space, but both sides have tested ASAT weapons. It is with respect to ASATs that the militarization of space threatens to become uncontrollable. The overlap of ASAT and BMD systems only compounds the problem.

The United States' Development Of ASATs

Early in the race to exploit outer space, the United States took the initiative in developing ASATs. In the 1950s both the navy and the air force prepared the ground by deploying radar systems for space surveillance. In 1964 the United States became the first nation to test ASATs, relatively primitive devices using Nike-Zeus ABMs and air force Thor IRBMs. Two ground-based special-purpose ASAT systems were deployed in the Pacific in the 1960s, one of which remained operational until 1975. When the expected threat—a Soviet orbital bombardment system—did not materialize, this particular deployment was abandoned. Even under Eisenhower, U.S. studies concluded that the earth was "the best weapons carrier"; the Soviets apparently came to the same conclusion. They began to test an ASAT in 1968, stopped three years later, then resumed testing in 1976, which triggered renewed U.S. interest. President Carter attempted to negotiate a treaty designed to stop further ASAT developments. Talks were held in 1978, but the Soviets were not particularly interested. Early in the 1980s the Soviets offered to negotiate a ban on the testing of space weapons, but by then the Reagan administration was becoming committed to the development of a U.S. ASAT.

The launching of Sputnik in 1957 galvanized the U.S. space program, bringing projects to fruition. Reconnaissance satellites had been under study from early in the 1950s and had already benefited from the adoption of the recommendation of the Strategic Missile Evaluation Committee chaired by John von Neumann in the spring of 1954, which urged that the United States give "highest priority" to the development of ICBMs. Given that a rocket capable of sending a warhead an intercontinental distance can also, in general, launch a satellite of approximately the same weight, this decision meant that a sufficient launch capacity would also be available for satellites. The official, unclassified U.S. space program, however, gave initial priority to a scientific satellite, developed in 1955 under Project Vanguard. After Sputnik, however, political pressure led the Eisenhower administration to establish ARPA and then to transfer responsibility for military satellites to the services and the CIA, whose Project Corona reportedly resulted in the launching of satellites that took film and ejected the cannisters for air recovery.

Even before Sputnik, however, the air force had initiated a highly classified program of its own, called the Satellite and Missile Observation System (SAMOS), and also cooperated with the CIA's Corona program, which reportedly used air force Project Discoverer satellites. The downing of U-2 pilot Gary Powers in 1960 stimulated further increases in funding for Project SAMOS.

In general, Sputnik and the U-2 incident stimulated a new commitment to the use of space for military purposes. According to widely published reports, an organization called the National Reconnaissance Office was created in 1960. Air Force officers in particular urged that military activities in space be given high priority. Thus Gen. Bernard Schriever called on the United States to achieve "space superiority," and others argued that air and space were becoming indivisible fields of military operation. The air force made a special claim to the "space mission," though both the army and the navy put their own cases forward for control of satellites.

In the Eisenhower administration, the case for observational satellites was considered compelling. Eisenhower himself believed that because the Soviet Union was a closed society, certainly in comparison with the United States, reconnaissance satellites were crucial. Despite Soviet success with Sputnik, it was not clear at the outset that the Soviets would agree to satellite overflights. For this reason, such overflights were cloaked in secrecy. Because the United States was even more dependent than the Soviets on satellite reconnaissance, Eisenhower was reluctant

to approve the development of ASATs, inasmuch as this would give the Soviets an incentive to follow suit. He did permit exploratory development of the Satellite interceptor (SAINT) system because it was presumably designed for the interception (and inspection) of satellites rather than for their destruction.

It was well recognized, however, that U.S. satellites could not be easily protected by physical means. The United States therefore sought a politico-legal solution to their vulnerability by proposing international agreements to sanction or legitimate overflights by reconnaissance satellites. It proposed that space be used for peaceful activities, on the tacit understanding that reconnaissance satellites could be included because they were not weapons. At first the Soviets refused to agree to the proposals, but their view changed as they acquired their own reconnaissance satellites. As early as May 1960, Khrushchev expressed the view at an international meeting with other heads of state that photographic reconnaissance by satellites was permissible, even though overflights by aircraft were violations of sovereignty. At the same time, however, Soviet officials continued to object to satellite reconnaissance. In 1962 the U.S.S.R. opened a diplomatic offensive at the United Nations aimed at prohibiting such activities through the adoption of a declaration of principles holding that "the use of artificial satellites for the collection of intelligence information in the territory of foreign states is incompatible with the objectives of mankind in its conquest of outer space."^[40]   

The Soviets changed their tune once their own Kosmos reconnaissance program began regular intelligence gathering and as progress was also made in the test-ban negotiations. They recognized that satellite reconnaissance could provide a way around the need for on-site inspection. By September 1963, the Soviets had ceased opposing the United States' call for legitimating satellite reconnaissance.

Meanwhile, the U.S. had not restricted its efforts only to reconnaissance satellites. Both the army and the navy developed ideas for ASATs. The army considered converting the Nike-Zeus into an anti-ballistic missile, and the navy worked on modifying the Polaris missile to serve the same purpose. The air force had the most ambitious program: in response to Soviet civil space activities, it proposed in September 1961 that the United States adopt a ten-year plan for satellite interception, space-based ballistic missile defense, a fast-reaction space bomber that could reenter the atmosphere, and a manned capability in space. The Kennedy administration rejected the proposal for a manned space facility but agreed that ASATs deserved closer consideration. This decision

was certainly reinforced by Khrushchev's threat to place bombs on orbiting Soviet satellites.

In the early 1960s McNamara took a highly secret decision to allow the army to develop a modified Nike-Zeus under the code name Mudflap, later designated Program 505.^[41]    This system became operational on August 1, 1963. Earlier that year the air force was instructed to prepare an additional ASAT, using the Thor missile (alias Project 437). This was tested in February 1964. Nike-Zeus had the advantage of using a solid propellant, but the Thor could reach higher altitudes. Both were designed to use nuclear warheads, a disability inasmuch as their use would have threatened U.S. satellites in the vicinity and their testing would have violated the Limited Test Ban Treaty. Project 437 nevertheless remained in place on Johnston Island until 1975.

In 1963 the United States proposed, and the Soviets agreed, that the United Nations should issue a declaratory ban on weapons of mass destruction in outer space. The Soviet Union had already experimented with satellites designed to carry large nuclear weapons, which the United States called a Fractional Orbital Bombardment System (FOBS). But it evidently determined, as the United States had independently, that terrestrial systems were preferable for such purposes. In 1967 both nations signed a treaty banning weapons of mass destruction from placement in space. Neither the declaratory statement nor the treaty banned the development of ASATs. The United States proceeded with ASAT development as a hedge against surprise and possible Soviet abrogation of the treaty, and also in order to have the ability to attack satellites in time of war.

U.S. concerns were aroused in 1966 and 1967 by Soviet launches from Tyuratam, Kazakhstan. Apparently, the payload portion was commanded down to earth before one complete orbit. McNamara interpreted the launches as an attempt to develop FOBS satellites designed to serve as weapons carriers that would approach the United States from the south, its most vulnerable flank. To counter this threat, the United States utilized over-the-horizon radar, with increased coverage of the southern United States, and commenced development of a new ABM—the Nike X.

As early as 1958 ARPA sponsored a series of experiments called Project Argus, designed to assess certain of the effects of nuclear explosions in space. The Fishbowl series above Johnston Island in 1962 included one large nuclear explosion with a yield of 1.4 megatons; several satellites were damaged.

The navy in 1961 also proposed a direct-ascent ASAT in its modified

Polaris. The air force's SAINT had been designed as a co-orbital device, which must go through several space orbits before it achieves the same orbit as its target. So as not to give the Soviets an excuse to shoot down U.S. reconnaissance satellites, SAINT was designated an "inspection" system rather than as an interceptor. In January and February 1958, Eisenhower sent two letters to Bulganin, referred to earlier, proposing a cessation of all military activities in space, including the testing of long-range missiles. The proposal was conditioned on the creation of an international system for observing and verifying compliance. The U.S.S.R. rejected the proposal, calling it an attempt to hinder Soviet progress. In May 1962, as part of Project HiHo, the Navy test-launched a rocket from a Phantom F4D fighter bomber with a secondary objective of launching ASATs. In 1970 research began on the Miniature Homing Vehicle (MHV), the basis of the United States' current ASAT. The MHV is an air-launched heat-seeking missile that homes in on a target satellite and destroys it by force of impact. The United States has been developing this weapon since 1977, using an F-15 aircraft modified to serve as a launch platform. It is currently estimated that this ASAT could be ready for deployment in 1990 at a cost of $4 billion.^[42]    Other efforts were pursued to improve space tracking and detection, which also served to improve prospects for an effective ASAT. And in the mid-1970s attention was directed to the need for an improved satellite survivability.

The Soviet Military Space Program

In 1968 the Soviets began testing a satellite interceptor, or "killer satellite." By 1970 there was little doubt among Western observers that the U.S.S.R. had succeeded in developing an ASAT. The Soviet system uses a large liquid-fueled booster to launch a satellite that must move through more than one orbit until it can be maneuvered close enough to its target to be exploded. Destruction is achieved by the impact of shrapnel from the explosion. The testing stopped in 1972, resumed in 1976, and later was interrupted again when the Soviets declared an official moratorium on ASAT testing, done in conjunction with a proposal to extend the ban on space weapons to include ASATs. In 1977, however, Secretary of Defense Harold Brown asserted that the Soviets now had an operational ASAT—though it was effective only against satellites in low orbit. Given that most of the United States' critical early-warning and communication satellites are in high orbits, this first-generation system would be of limited utility. In addition, the Soviet ASAT is co-orbital,

meaning that it cannot be used very effectively in a surprise attack: the time needed to put the Soviet killer satellite into operation would give the United States ample warning that the Soviets were at least contemplating such an attack.

By the time Jimmy Carter took office, unilateral Soviet development of ASATs had come to be perceived as politically, if not militarily, unacceptable. On the advice of Brown, Carter concluded that the United States should undertake a three-pronged response. First, the United States should institute the development of a general-purpose ASAT of its own. (This is the origin of the current F-15-based system.) Second, the United States should intensify efforts to make its own satellites safe from, or at least resistant to, attack by Soviet ASATs. And third, the United States should attempt to negotiate a treaty regime with the Soviets designed to eliminate, or at least inhibit, the further development and deployment of ASAT systems.

In accordance with the third objective, bilateral negotiations were conducted with the Soviets in 1978 and 1979. Despite doubts in certain defense quarters, Carter pushed for the broadest possible limitation. At first, the Soviets indicated that they doubted the desirability of a total ban on ASATs and sought to limit the negotiation to something more like the "rules-of-the-road" arrangements that prevail at sea. Before these negotiations could get very far, other events such as difficulties with SALT discussions and, ultimately, the invasion of Afghanistan brought about the termination of these formal efforts to control further development of ASATS. On April 3, 1980, the Soviets resumed ASAT testing. By then, however, the two sides were close enough to an agreement to arouse expectations that if Carter had been reelected an agreement would probably have been concluded.^[43]   

In August 1981 the Soviets offered to discuss a draft space-weapons treaty to be submitted to the U.N. General Assembly. This time it was the United States that showed no interest. Indeed, in June 1982 the air force announced the creation of its Space Command, headquartered at the NORAD complex at Cheyenne Mountain. In the summer of 1983, in a meeting with the U.S. senators, Premier Yuri Andropov offered to amend the Soviet proposal so as to ban the placement of anti-satellite weapons in outer space, along with the testing of any new ASAT. He also offered to eliminate existing systems. The proposal also included a provision that the Soviets knew the United States would not accept: it prohibited the testing of any manned-space vehicle for military purposes, to which the United States was committed using the space shuttle. But

the Soviet proposal impressed the legislators, and they supported the amendment offered by Sen. Paul Tsongas (D., Mass.) to the FY1984 DOD Authorization Act. The amendment prohibited the use of the funds for testing the ASAT against targets in space until the president certified that the United States was negotiating the matter in good faith with the Soviet Union.^[44]   

Prospects for such a treaty are still unclear. Some of its U.S. advocates concede that it is now impractical to prevent the development of ASATs effective against satellites in lower orbits, but they argue that a prohibition of their deployment in significant numbers, and of the testing and development of ASATs capable of destroying satellites in higher orbits, would still be possible and would be in the interests of both powers. Prohibition of the more advanced ASATs could be especially important because most of the critical satellites are in these higher orbits. In addition, the two powers might agree to "rules of the road" similar to the agreements now operative at sea.

Civil Space Cooperation

Although continued emphasis on the military uses of space has not yet altogether precluded international cooperation in space exploration, it has already engendered a climate of suspicion and concern for national supremacy that belies the professions of political leaders that space should be an arena for peaceful exploration in the interest of all humanity. The Apollo-Soyuz docking was the first, and so far the only, instance of official U.S.-Soviet activity in space. Scientific data have been exchanged, however, and the Soviets have lately been more open about their civil activities and plans, an attitude that has evoked appreciation and interest among Western space scientists, who admire the ambitious character of the Soviet program. The disarray and uncertainty that have characterized the U.S. government space policy present a sharp contrast. The Soviet Vega mission to Venus in 1984 involved considerable international cooperation, including one U.S. experiment. Otherwise, cooperation at higher levels has been hostage to general political relations. In 1982 the Reagan administration allowed an agreement on space collaboration with the U.S.S.R. to lapse, in protest against the imposition of martial law in Poland. In 1987, after the leaders of both countries concluded a summit meeting and were eager to make some symbolic gesture of amity, a new agreement was signed. The U.S. team that negotiated the agreement included DOD representatives, who made sure that

technology transfer would not be included. As a result, the agreement calls for little more than the exchange of data and the coordination of mission schedules, but "carefully avoids proposing that researchers from one side fly instruments and other hardware on the other's spacecraft."^[45]    Leading Soviet space researchers have proposed that the two countries collaborate, in ways that would respect DOD sensitivities, on an unmanned mission to Mars scheduled for the early 1990s. NASA has so far declined to commit the United States to such a collaboration, although there is reported to be considerable interest in it.

Along with the ABM Treaty, such collaboration could well be another casualty of a decision to deploy space weapons. Although space has from the first not been treated as a sanctuary in the strictest sense, the willingness on the part of both superpowers to refrain so far from orbiting all but military support systems has preserved a basis for civil cooperation. If space is further militarized, especially by the use of camouflaged weapons, decoys, and declared "keep out" zones, such collaboration is likely to become increasingly difficult. Information on the location of satellites and on conditions in outer space is likely to be treated as a matter of national security, along with virtually all aspects of space technology.

Despite the overwhelming evidence that past efforts to achieve strategic defenses have been largely an exercise in futility, and despite the real possibility that the future militarization of space will preclude both arms reductions and civil cooperation, the elusive quest for strategic defenses continues. Do prospective technologies promise better results, or will they only repeat the folly? We examine these prospects in the next chapter.