January 21, 1988

January 21, 1988 | Backgrounder on National Security and Defense

"The Strategic Defense Initiative: A Shield, Not a Sword"


(Archived document, may contain errors)

I 628 January 21, 1988 THE STRATEGIC DEFENSE INITIATIW A SHIELD, NOT A SWORD INTRODUCTION Soon after Ronald Reagan launched the Strategic Defense Initiative (SDI) in 1983, Moscow began to argue that, in reality, this new program was a cover for a U.S. effort to develop space-based offensive weapons. More recently, the Soviets have claimed that the purpose of SDI is to build a shield behind which the U.S might launch a first strike on the,Soviet Union. Although this is part of the Soviet propaganda campaign against SDI, some U.S. opponents of SDI echo similar views.

These arguments are without merit. SDI is a defensive shield, not an offensive sword. Reasons 1) The laws of physics make it almost impossible to use SDI's defensive technologies, including directed energy, to achieve the mass destruction caused by strategic nuclear weapons. Even if it were possible, it woul d make little sense to duplicate capabilities the U.S. already possesses developed any time soon 2) It is dmbtul that even modest offensive space-based systems can be 3) Even if modest space-based offensive systems could be developed, it would take years a n d cost billions of dollars 4) The deployment of strategic defenses could not give the U.S. the ability to launch a first strike against the Soviet Union, as the Soviets suggest, given the low ratio of first-strike capable US. missiles and warheads to Sovi e t targets This is the 48th in a series of Heritage studies on strategic defense. Previous papers included Backgrounder No. 623, "A Timetable for Deploying A Strategic Defense December 14, 1989, and Backgrounder No. 621 Basing Deterrence on Strategic Defen s e December 2, 1987 2 A major advantage of SDI development, moreover, contradicts the Soviet argument about weapons of mass destruction. The unique characteristics of certain SDI technologies may speed the development of high technology, non-nuclear tactic a l weapons. This thus reduces, not heightens, the threat of mass destruction. Lasers now are being used for targeting and guiding conventional munitions. High energy lasers and -.other--modern non=nuclear-weapons...may.~prove-.usefu.l--as battlefield weapo n s, fired from the ground, from aircraft, or from low earth orbit, Such systems may be able to strengthen U.S. and NATO conventional defense capabilities against a non-nuclear Soviet attack on Western Europe. That possibility should be explored thoroughly i n cooperation with the NATO allies no evidence that SDI is for offense .or that it will become so. The SDI program should proceed at a rapid pace. It will protect the U.S. from nuclear attack and yield dividends for non-nuclear weapons as well SDI will no t produce "space strike'' weapons for offensive purposes. There is ORIGINS OF OFFENSIVE USE THEoRlEs SDI weapons in space could be a cover for preparations for a disarming first strike against Soviet missiles and that space-based weapons could.be used for o ffensive or space strike" purposes. The Kremlin has contended that placing such weapons in space, even for defensive purposes, would increase U.S. offensive capabilities. Some studies by Americans have probed the Soviet assertions. A very tentative report by R D Associates of California,l for example, reviews possible offensive uses of certain SDI technologies as a basis for suggesting that SDI could have strategic offensive capabilities. The R D Associates paper discusses the feasibility of using high-pow e red lasers of the kind under development in the SDI program to create massive fires in urban areas and some kinds of military installations. The authors however, are careful to warn the reader that "almost evkry statement in this brief report requires fur t her study In addition, R D Associates made no attempt to determine cost-effectiveness or to compare SDI with competing concepts. This did not prevent U.S. and foreign SDI opponents from using the seven-page study as the basis for allegations about the off e nsive potential of SDI Certain other SDI concepts have been seized upon by SDI opponents to illustrate the supposed offensive use of space-based defensive weapons. Because of the drastically reduced time scale for such advanced SDI technologies as lasers to reach their targets (laser weapons strike with the speed of light SDI opponents argue that the temptation to conduct a first strike against the Soviets could be greater with space-based offensive weapons than with current strategic systems.

Accordingly, the argument goes, their development could undermine strategic stability Within month: after Reagan launched SDI, Moscow began suggesting that 1. Albert L. Latter and Ernest Martinelli SDI: Defense or Retaliation R D Associates, May 28 1985. -3 WHY SDI I S NOT OFFENSIVE SDI Provides No New Strategic Capabilities There are several problems with the suggestion that SDI will use lasers to destroy military-targets on the -earth+surface and- to start-urban--conflagrations. For one thing, there are serious techn i cal difficulties in using laser weapons to strike down through the earth's atmosphere; cloud cover over a target area, for instance dissipates laser beam intensity. For, another thing, even if defensive technologies could start "urban conflagrations this would not give the U.S. a militarily meaningful capability in the age of nuclear-armed ICBMs.

There is no way, moreover, that SDI weapons could destroy missiles in their Without being able to approach the capability of silos or other hardened military targets as confidently and effectively as highly accurate nuclear-armed ICBMs.

ICBMs, the impact of SDI technologies on the offensive strategic military balance is likely to be no more than marginal.

SDI opponent Robert English, a member of the group that calls itself the Committee for National Security, claims that While the presence of thick clouds would impede a laser strike,' an attacker has the luxury of waiting until conditions are ideal (the de f ender does not)."2 This ignores the obvious..facts that the U.S has neither a first-strike policy nor capability and that, if hostilities were already under way, it would be ridiculous in an age of high-speed weapons, such as ICBMs to wait for good weathe r before striking. A laserl weapon that I must wait for good weather or a favorable position in orbit to be used provides little added offensive capability to U.S. strategic forces Spacebased Menses Are Incompatible with U.S. Targeting Policy U.S. strategi c targeting policy has not included deliberate attacks on Soviet cities for the purpose of killing people since the original massive retaliation concept was officially discarded. Use of SDI lasers in an offensive role to cause urban incineration thus makes no sense in terms of current or projected U.S. national security policy. For nearly two decades, official U.S. strategic policy has placed the highest targeting priority on the Soviet military, its political leadership, and critical economic targets. The o bjective is to strike such targets with as few non-combatant deaths and as little residual damage as possible important targets that are underground, well defended, or otherwise protected can be attacked at all, they can be struck far more effectively wit h nuclear weapons than with any present or prospective SDI weapons, such as lasers or.other directed energy devices. And even if it were U.S. policy to cause urban conflagrations which it is not it could do so far more effectively with nuclear weapons than with any known defensive technologies To the extent that militarily 2. Robert English, "Reagan's Peace Shield Can Attack, Too 27ie Washington Post, February 15, 1987.

I 4 A U.S. First Strike Is Impossiile Moscows assertion that Washington might use space- based strategic defenses as a shield behind which the U.S. might launch a nuclear first strike is contradicted by the U.S. force structure. While the Soyiet Union has developed and deployed a first-strike=nuclear -force the-IU,S has t The Sovietsy.~av~..d e ployed 1,398 large land-based ICBMs, giving Moscow asuperiority of 3 to 1 in overall nuclear throw weight and 10 to 1 in hard target kill throw-weight. Moscow has 5,240 nuclear warheads on its first-strike capable SS-18 and SS-19 ICBMs, or five times the number of such weapons needed to destroy the entire U.S. land-based nuclear deterrent force.

By contrast, the U.S. has operational only 14 MX ICBMs and 300 Minuteman L missiles with the new MK 12A warhead. These missiles carry a total .-of 1,040 of those w arheads whose yield and accuracy make them first-strike capable weapons although the capability of the 300 Minutemen is questionable. Even .including the Minutemen, this is not nearly enough warheads for the U.S. to contemplate a first strike. It would re quire at least three warheads for each Soviet ICBM, or 4,200 first strike capable warheads. This is nearly four times as many as the U.S..has operational.

Insufficient numbers of U.S. first-strike offensive weapons prevents the U.S from contemplating a fir st strike, even if it wanted to do so. SDI does not change this fact in any way. Even if the U.S wanted to launch a first strike behind an SDI shield, it would not have enough first-strike .warheads to do the job On the other hand, Moscows huge arsenal of such weapons means that the Soviet first strike threat to the U.S. would be greatly increased if Moscow were to deploy comprehensive strategic defenses Offensive SDI Would Face Effective Countermeasures SDI opponents curiously are silent about possible So v iet countermeasures to an offensive use of SDI. This is in sharp contrast to the host of countermeasures that SDI opponents envision against the defensive use of SDI. Yet, even cursory examination reveals that it is likely to be far easier to develop coun termeasures to space-based offensive attacks against, targets on land than it is to develop countermeasures for SDI defensive attacks against Soviet missiles in space on their way to U.S. targets.

Most surface targets could be shielded, placed underground, or otherwise hardened (as Soviet missile silos have been hardened with reinforced concrete walls and steel covers) to a very high degree against a space-based offense, and probably could be protected to a degree that would require laser power beyond the inherent capability of space-based or redirected weapons.

Concern about offensive attacks by ground-based laser beams, which are reflected and directed by space-based mirrors to targets on the ground, fails to consider that the mirrors themselves would hav e to be made sufficiently reflective to withstand the laser effects. But if mirrors could be developed to reflect high energy laser beams without damage, then, as a countermeasure, protective reflector -5 mirrors could be placed on the ground as passive d e fenses to deflect laser beams away from high priority land-based targets SDI Weapons Have Limited Military Value Against Soviet Targets Even if. SDI weapons .had? some7 offensive^ capability -against.-stationary Soviet military targets on the ground, it w o uld be of limited future value. In recent years Moscow has given high priority to both defensive and offensive mobile weapons systems, thereby reducing their vulnerability to attack. The two newest Sovlet ICBMs, the SS-24 and SS-25, are mobile and difficu l t to target and track. Even with regard to easily targeted missiles in fixed silos, there is some suspicion that many Soviet ICBM silos do not contain missiles at all, and that the missiles themselves actually are dispersed and hidden throughout the vastn e ss of the Soviet land mass Uses of Kinetic Energy Weapons in Space Are Limited The use in space of kinetic energy weapons (those that destroy targets by impact) to attack surface-based strategic targets in the Soviet Union, including such hardened targets as missile silos, is unlikely to be militarily or economically effective. Such an offensive system is not likely to replace or even supplement ballistic missiles, cruise missiles, or other offensive weapons that use nuclear explosives.

Kinetic energy weap ons designed to be launched from platforms in space against targets on earth would require enormous and costly space-launch payloads to get all that equipment into orbit. The weapons would suffer major problems moreover, on re-entering the earth's atmosph e re. While such weapons could be designed to prevent burn-up on re-entry, they still would have to contend with the problem of serious air drag and deteriorating accuracy Moreover, the terminal guidance systems being considered for advanced U.S strategic m i ssile systems could not be applied to small space-based offensive kinetic energy weapons. defended ground targets while traveling at high speeds. In fact, it is doubtful if the relatively large and complex pidance systems designed for strategic missiles a nd warheads would be at all compatible with small, space-based kinetic energy ,,weapons.

Even if space-based systems could strike in seconds, compared with the 30 minutes or more for intercontinental ballistic missiles, such systems would hardly be suffici ently effective to produce anything approaching a credible alternative to nuclear-armed ballistic missiles would be too great These would have to be guided with great precision against The problems of feasibility and cost ineffectiveness 3. Samuel Cohen a n d Joseph Douglass, "Arms Control, Verification and Deception National Securify I. Record, December 1985 6 Cost Problems Are Immense There are immense technical and cost problems associated with the concept of space-based kinetic energy systems designed fo r strategic offensive use Fundamental design differences exist between a kinetic energy defensive system whose performance requirements are-.-based .on. destroying- an-=extremely soft target such as a rocket booster in flight, and an offensive system that has to .identi

and destroy targets on the earth's surface, which can easily and cheaply be concealed and hardened.

Further, space-based non-nuclear kinetic energy systems easily could be much more expensive than an offensive system of earth-based strateg ic nuclear missiles The number of satellites required to gain adequate offensive coverage by small space-based weapons against the thousands of military and strategic targets in the large land area of the Soviet Union would be vastly more than the one to t wo thousand satellites estimated to be needed for a' strategic defense that would intercept ICBMs in the "boost phase" shortly after their launch. Add to the large number of satellites the huge payloads needed to put in space high energy lasers or kinetic energy weapons with sophisticated guidance systems, and the cost of a space based offensive system is likely to be astronomical SDI Development is InC0mpatiile~'with Offensive Use There is the mistaken impression that offensive kinetic energy weapons coul d be developed and deployed in space clandestinely as part of the SDI program. I This is simply untrue. There would be fundamental differences between the development and testing of kinetic energ) offensive and defensive systems, involving different radars and sensors and different targeting and atmosphere penetration requirements. There is no way that an offensive space-based system could be deployed under the aegis of a defensive system To the technical and cost barriers to a practical offensive system mu st be added the dangers of the strategic arsenal's including very fast weapons that are extremely difficult to target accurately. iSuch weapons would be fired from moving platforms and would need very complex guidance systems.

Considering the technical unc ertainties and high costs that would be involved it is incomprehensible that any U.S.:adniinistration would try to deploy a "covert strategic offensive capability under the guise of a defensive one. It would be close to impossible to carry out such a subt e rfuge in the open American society without Congress or the press learning about it, at least in peacetime NON-NUCLEAR OFFENSIVE POTENTLAL OF NEW 'lECJ3NOUlGlES Though the new technologies being developed under the SDI program will be of little use to offe n sive nuclear forces, they show considerable promise for offensive conventional weapons. No one, including SDI opponents, raises objections to using new non-nuclear technologies for the development of conventional weapons. Such targets as tactical aircraft , Airborne Warning and Control System (AWACS) planes 7 battlefield missiles, communications systems, and theater command and control centers, which would not be primary targets in a strategic nuclear war, would be high priority targets in a regional, conve ntional conflict. Such a conflict is almost certain to be outside the USSR. Anti-satellite defenses thus are likely to be significantly weaker than those inside the main target areas of the Soviet Union.

In a conventional -conflict; too, -with-large-number s *of troops-and-equipment on the move, it would be difficult to conceal critical targets from reconnaissance. It also should be easier to hit conventional targets with short-range space-based weapons than with the longer-range systems that would be neede d for strategic purposes If the full non-strategic offensive potential of SDI-spawned weapons technologies were to be realized, the result would be an ideal coupling of weapons delivery and target vulnerability. Targets could be attacked and destroyed by n e w high-tech weapons immediately after identification, before they have 5 time -.to: move out of harms way. Such weapons might include high energy lasers in orbit or redirected by mirrors in space, or the hypervelocity kinetic energy projectiles in space t h at are now being developed,,under the SDI program CONCLUSION Assertions by Moscow and by some American critics of SDIlthat the SDI program may have strategic offensive applications have been neither accurate nor objective. SDI is a defensive program, base d on sound moral and strategic goals. Its purpose is to move the U.S. away from the doctrine of Mutual.Assured 6 Destruction (MAD which contemplates the destruction of American society. In the long run, MAD endangers U.S. survival; by contrast, Soviet stra t egic defensive programs, active and passive, are intended to ensure the survival of the Soviet leadership Echoing Moscow. The attempt to label SDI as offensive is reminiscent of the attacks made against the development of the neutron bomb a decade ago? Ma ny of the leading foes of that weapon have re-emerged as outspoken opponents of SDI using similar arguments. The arguments of these opponents today against SDI, and earlier against the neutron bomb, closely match the positions of the Soviet Union.

These SDI opponents previously had put forth almost every conceivable reason why SDI defenses would not work effectively, while at the same time arguing that, if strategic defenses did work, they would dangerously destabilize the strategic balance.

Now that it has become clear that SDI indeed is technically feasible, these same SDI opponents appear to claim that SDI technology is so highly feasible that it holds great offensive potential 4. Alton Frye, The High Risks of Neutron Weapons, The Washingt o n Post, July 17, 1977. -8 The SDI program to develop strategic defenses for the U.S. should be accorded the highest national priority unsubstantiated claims that it has a dangerous and destabilizing potential for strategic offense It should not be impeded by false Samuel Cohen is a Los hgeles defense consultant and is known as the father of the neutron bomb All Heritage Foundation papers are now available electronically to subscribers to the "NEx7S" on-line data retrieval service. llie Heritage Foundation' s Reporls (HFRF'TS) can be found in the OMNI, CURRNT MTRS, and GVT group fires of the NEXIS library and in the GOVT and OMNI group fires of the GOWS library.

About the Author