459 September 30, 1985 MANAGING THE TRANSIT1 ON FROM NUCLEAR OFFENSE TO STRATEGIC DEFENSE INTRODUCTION Among the most challenging aspects of strategic defense is how to 1 1 I manage the transition from a solely offensive strategy to one that is systems ma i nly defensive and how to set priorities for the emerging defensive Current U.S. strategic doctrine, arms control policy, strategic force structure, and war plans are based on the concept of mutual assured destruction (MAD Revising this fundamentally, alon g the lines of Ronald Reagan's Strategic Defense Initiative (SDI), could produce an upheaval in the nation's security posture and policies.

Doctrine will have to be rethought; force structure rebuilt; and arms control objectives revised. The transition to defense dominance will be every bit .as revolutionary as the original transition to offense dominance (Ilassured destructionll Rather than being paralyzed by the uncertainties of the long-term technological possibilities for strategic defense, U.S. policy should proceed immediately to define near-term SDI objectives near-term objective is deployment of defenses for U.S. ICBM missile sites. At the same time, the U.S. should begin planning for a long-term transition from an offensive posture to a defensive o ne.

This would include integrating arms control considerations based on a defense-dominant strategic environment into long-term U.S. strategic The main 1. This is the twelfth in a series of Heritage Backnrounders on Strategic Defense. A complete list appea rs at the end of this study planning. Finally, long-term strategic defense requires strengthened protection -against enemy aircraft and improved civil defense.

NEAR-TERM SDI GOALS The only near-term goal of the SDI stated consistently by the Reagan Admini stration is to determine the lvfeasibilityl1 of strategic defense, a rather elusive objective in view of the disagreement concerning what "feasiblemt means in this context. The absence of clearer short-term objectives is a problem because it prevents SDI f rom gaining self-sustaining momentum. Unless SDI produces tangible results, such as deployment of defensive missiles, and acquires the bureaucratic momentum of an ongoing program, it may not survive in a political system noted for its short attention span .

Deployments mean production, and production means jobs, far more jobs that a research and development program is likely to generate.

The political constituency for the SDI created by widespread employment in producing defensive systems will probably be larger and more durable that any constituency based on abstract devotion to the ideal of Itassured survival I Experience has demonstrated that protracted research efforts are most successful when intermediate objectives have been set that permit managers t o gauge .progress. In addition, near-term deployment of defensive systems, even if not designed for population defense, would provide useful indicators of the SDI's progress toward the ultimate goal of protecting American society I The most practical near - term deployment option for SDI technology is an active defense of ICBM silos and other hardened strategic sites. Such installations are intrinsically easier to defend than softer targets like cities. Some SDI proponents resist early deployments of defense s to protect ICBMs because they fear that this will reinforce the prevailing strategic posture and undermine commitment to population defense. This reasoning overlooks such considerations as 1) Soviet strategic forces are designed for a preemptive first st r ike against the U.S. retaliatory forces at the start of a nuclear war. Active defense of U.S. forces would greatly diminish Soviet expectations for the success of such an attack. In so doing, the defenses reduce the perceived military utility of Soviet mi s siles and thus represent progress toward the long-term objective of rendering these missiles "impotent and obsolete 2) The transition from the current strategy of assured destruction to a defense-dominant posture will be accomplished only in stages over s e veral decades. During the early transitional stages 2the U.S. will have to rely upon its offensive weapons to deter Soviet efforts aimed at preventing defensive deployments. Thus, active defenses to protect the integrity of the U.S. offensive forces may b e a necessary prerequisite for a stable defensive transition difference between weapons designed to protect silos and weapons designed to protect people. SDI expert Fred S. Hoffman explained to the Senate Armed Forces Committee earlier this year: "defenses do not come in neat packages labelled 'protection of military targets' and protection of civilians.' Warheads aimed at military targets will in general, kill many collocated civilians and defenses that protect against such attacks will reduce civilian cas u alties 3) It is misleading to imply that there is a fundamental Near-term deployments of U.S. missile defenses, of course, could mitigate the effects of limited Soviet attacks against such nonmilitary U.S. targets as urban or industrial areas. The convent i onal wisdom of assured destruction visualizes attacks on the U.S. largely in terms of massive strikes against urban centers. But it is hard to see a military utility for Moscow in such attacks if they would lead inevitably to unrestrained U.S. retaliation . For this reason, most of the nonmilitary targeting in Soviet war plans is probably quite limited in scope be able to protect against these attacks, just as they could against the similar threat to the U.S. posed by the People's Republic of China or other adversaries with limited nuclear capabilities Thus less than perfect defenses may Near-term defenses also could offer protection against accidental nuclear attacks command failures probably would be limited in scope and thus susceptible to interception by first-generation SDI systems Launches resulting from technical malfunctions or In sum, there are persuasive political, scientific, and military reasons for planning near-term deployment of ballistic missile defenses that offer less than comprehensive prot e ction of'the U.S population during the early stages of the defensive transition, such deployments lead to SDI long-term goals by discouraging destabilizing Soviet behavior, building a political constituency for strategic defense, and providing useful oper a tional experience. Ideally, near-term deployment of partial defenses should be capable of serving as'the first stage in a multi-tiered population defense system. But other objectives, such as protecting offensive forces, are equally important in the near t erm Particularly as defenses of offensive nuclear forces 3- LONG-TERM GOALS In Ronald Reagan's original 1983 formulation of his Strategic Defense Initiative, the ultimate objective was to render nuclear missiles 'Iimpotent and obsolete.Il The 1984 preside n tial directive authorizing the effort, National Security Decision Directive NSDD)-119, diluted this to the goal of "enhancing deterrence The Defense Department's Reno& to the Conaress on the Strateaic Defense Initiative, released earlier this.year, used s i milar terminology in its discussion of objectives strengthening strategic stability: increased security of the United States and its Allies; and eliminating the threat of ballistic missiles consist of more than simply the introduction of a system that def e nds against ballistic missiles. It would require defense against bombers and cruise missiles and civil defense protection on a comparable scale Other goals of the SDI cited in the report to Congress included But over the long term, a true defensive transi t ion would SDI FORCE STRUCTURE EVOLUTION Defensive' Forces The United States today has no significant defenses against a nuclear attack: it relies exclusively on the retaliatory threat posed by its offensive arsenal. The long-term goal of the defensive tra nsition is to develop nonnuclear defensive systems capable of taking over the role currently played by offensive nuclear forces in deterring war and mitigating its consequences.

In 1983, a team of nongovernmental experts concluded that intermediate missile defense deployments were the llpreferred path" to attaining the President's long-term goal of eliminating the threat posed by ballistic missiles. For this, the team identified three short-term applications of SDI research 1) defenses against short-range ( tactical) ICBMs 2) selective defenses of "critical installationst1 in the continental United States, and 3) a limited 0 2. The long-term deployment options proposed above are described without any definition of what "long term" means. The reason is that t e chnologies needed to make each of the various options feasible are not yet available. Whether they become available in the 1980s or the 1990s or the next century will be determined largely by the way in which SDI program objectives are defined 4boost-phas e interception system. Combining these technological possibilities with the various mission objectives set forth for transitional deployments in the preceding section suggests several near-term missile defense options 1) Hard-point terminal defenses of str a tegic assets such as missile silos and communication nodes 2) Ground-based defenses of missile sites (terminal defenses which would intercept incoming missiles in the upper atmosphere endoatmospheric region) and during their .midcourse phase. These would r einforce point defenses and/or protect relatively exposed U.S strategic assets such as bomber bases 3) Ground-based terminal and midcourse defenses designed to protect nuclear and conventional military sites in Europe against attack by Soviet Intermediate - Range Ballistic Missiles (IRBMs) and Medium-Range Ballistic Missiles (MRBMs 4) Ground-based or space-based midcourse defenses designed to provide a moderate defense of urban and industrial sites in Europe and North America against limited nuclear attacks 5 ) Early deployments of space-based systems to intercept Soviet ICBMs in boost phase and thus enable the destruction of some Soviet ballistic missiles prior to release of their multiple warheads and penetration aids 6) Combinations of the preceding possibi lities deployed together .in a near-term, layered defense system.

Assuming that these missions, such as silo-defense, light protection of cities, are deemed worthwhile, it.makes sense to deploy systems to achieve these ends as they become available rather than waiting for the perfect defense.

The most promising near-term option for transitional deployment of defensive technology would be mobile strategic defenses to protect U.S. ICBMs whose housing is designed to deceive the Soviets as to their exact locat ions. Follow-on options might include missile defenses of fixed strategic targets and, later, systems that defend by intercepting Soviet missiles in the upper atmosphere and above the atmosphere. Initial defense of cities against light or accidental attac k s could be provided by a layered system of interceptors designed primarily to protect missile sites, which attack their 3. For background on SDI technologies applicable to Europe, see W. Bruce Weinrod and Manfred R. Hamm Strategic Defense and America's Al lies," Heritage Foundation Backgrounder. No. 425, April 16, 1985 5-targets in the upper atmosphere, combined with ground-based defenses which intercept their target in its midcourse phase.

The U.S. Army's Strategic Defense Command is developing a variety o f ground-based interceptors that destroy objects on impact kinetic-kill) and sensors, which could be integrated into a multi-tiered network of considerable efficacy before the end of this century short-range homing intercept technology) low-altitude inter c eptor that defends missile sites; additional tiers could be provided by the High Endoatmospheric Defense System (HEDS) interceptors in the upper atmosphere and the Exoatmospheric Reentry-vehicle Interceptor The first tier of the network could consist of t he SR-Hit Subsystem (ERIS which hits targets above the atmosphere.

Sensor data would be provided by the Designating Optical Tracker DOT) rocket-launched infrared tracking system, the Airborne Optical Adjunct (AOA) infrared sensor mounted on a Boeing 767, a nd the ground-based Terminal Imaging Radar (TIR All these systems could be deployed in the mid-to-late 1990s if their development schedules were rationally structured. Strategic Defense Command is already investigating the battle management and communicat i ons needed to integrate the sensors and interceptors. The resulting terminal/midcourse defensive network could provide highly reliable protection of U.S. deterrent forces and significant protection of major urban areas against limited countervalue attacks .

Since attacks on U.S. strategic systems or on selected urban and industrial sites are the only rational Soviet nuclear war plan options, the technology under development by the U.S. Army as part of the SDI could negate substantiatly Soviet war-fighting c apabilities before the end of this century.

Offensive Forces During the protracted period of transition from MAD to a defense-dominant strategic posture, U.S. strategic forces probably will consist of an offensive and defensive mix defensive transition, t he offensive arsenal will continue to play its traditional role of deterring attacks on the U.S. and allied territory by threatening potential adversaries. In addition, offensive weapons will take on the new deterrent function of dissuading the Soviet Uni o n from taking military steps to prevent deployment of defenses. In this latter capacity, nuclear weapons will be used to facilitate their own extinction During most of the 4. The near-term, multi-tiered defensive network described above could not prevent a major Soviet attack against American cities. Without boost-phase destruction of a large percentage of Soviet missiles, it is unlikely that the threat posed by a major Soviet attack could be fully negated 6 The Soviet Union probably will deploy defenses a t the same time as the U.S. Assuming the long-term success of Soviet and American strategic defense efforts at the same point in the future, it will become impossible to preserve the viability of offensive forces in the face of highly effective defensive s y stems away. For the time being, the deterrent role of offensive forces is indispensable. They must be sustained and modernized, including upgrading the command and control system This point is many years As for land-based ICBMs, however, Congress has forc e d the Administration to accept options inconsistent with projections of future superpower defensive deployments. The U.S. land-based Minuteman ICBM is growing old and obsolete penetrate Soviet defenses, as could the proposed ten-warhead.MX missile. But Co n gress has limited fixed-silo deployment of the MX to a mere 50 units. In its.place, Congress is pushing development of a small, 15-ton, single-warhead ICBM, known as Midgetman It could not reliably Midgetman supporters argue that it is less "destabilizing " than MX because 1) it is not an efficient first-strike weapon and 2) it is not an attractive first-strike target possibility that Midgetman's single warhead might have to penetrate one or more layers of Soviet missile defenses. Multiple Independently ass u re the penetration of Soviet defenses by U.S. ICBMs; it is a question deserving serious review whether the U.S. should develop a missile that may not be able to penetrate defenses at the same time the intelligence community is predicting and the Administr a tion is encouraging Soviet defensive deployments This reasoning ignores the Targeted Reentry Vehicle (MIRV) technology originally was developed to 1 I I Congress and the Air Force have increased the Midgetman penetration problem by drastically limiting th e missilels size (and thus its payload) and selecting an overweight guidance system. The result is that there will be little or no room on Midgetman for sophisticated penetration aids even current Soviet defensive deployments is an open question.

Whether such a weapon can pen'etrate Preserving the deterrent role of U.S. offensive missile forces during the early stages of a joint superpower defensive transition will require greater attention to potential problems concerning the penetrability of Sov i et defenses. Accelerated development of aids .to assist in penetrating Soviet defenses is therefore necessary to cope with possible Soviet defensive deployments. The Pentagon should give particular attention to the precision decoys'and technology that ena b le warheads to maneuver and to fix on Soviet targets that are now being developed within the Air Force's Advanced Strategic Missile Systems program. Of course, the most sophisticated penetration aids are useless if Congress cuts Midgetman down to a size t h at precludes their employment 7AIR AND CIVIL DEFENSE Defense against bombers (air defense) and civil defense are crucial to the success of any process whose ultimate objective is a uclear-free world.Il Yet there is little evidence that the interdependence of ballistic missile defense and air defense is being seriously addressed by Washington either within SDI or elsewhere is much attention being given to the interaction between contemplated deployments of active defenses and possible passive defense of civ i lians Nor Conventional wisdom has it that there is no point in revitalizing air defenses until the feasibility of balli.stic missile defense has been determined, since both are necessary for a thorough defense and the latter is more challenging always be s o sea-launched cruise missiles on strategic bombers and submarines which are capable of overwhelming U.S. air defenses available or prospective technology will not necessarily upgrade the U.S. air defense system to stop thousands of cruise missiles with t h e same reliability that ballistic missile defenses can intercept ICBMs and submarine-launched missiles. Without upgraded air defenses, the introduction of extensive U.S. missile defense probably will prompt Moscow to shift its arsenal emphasis from ballis t ic missiles to air-breathing systems such as bombers and cruise missiles. Such a shift would improve strategic stability since the air-breathing systems are slower and less destructive. But until defenses against nonballistic missile threats were fully de veloped, the U.S. would still be quite vulnerable to nuclear damage.

While it is quite plausible that effective active defenses against missiles and aircraft will be available, these defenses may not be perfect require such passive defenses as fallout shel ters and urban evacuation plans, but the federal government has no plans for developing such a civil defense system That is true today, but may not The use of The Soviets are deploying a new generation of air- and Minimizing damage from a nuclear attack t h us will Currently, the U.S. is funding SDI studies of systems that would be vulnerable to a Soviet air-breathing weapons threat. Arguments that any system capable of coping with ICBMs can also cope with 5. For a discussion of the potential for defense aga i nst bombers, see Loren Thompson, "Air Defense: Protecting America's Skies," Heritage Foundation Backgrounder No 379 September 13, 1984 6. For discussion of civil defense and strategic defense see Brian Green, "The New Case for Civil Defense," Heritage Fou ndation Backnrounder No. 377, August 29, 1984 aI air-breathing threats are simply wrong. Arguments that highly reliable active defenses will eliminate the need for passive defenses are correct in principle but almost certainly unworkable in practice.

If th e ultimate objective of U.S. policies is a nuclear arms-free world, then'SDI is just one facet of the defensive transition for which the Reagan Administration should be preparing ARMS CONTROL POLICIES The existing structure of superpower arms control agre e ments consists of two components: strict constraints on defensive systems and loose constraints on offensive systems. An arms control regime compatible with the aims of a defensive arsenal by contrast mainly would limit offenses an overt threat to other n a tions would be limited; other kinds of active or passive defense would be permitted Only those defensive systems that represented At some point during the transition to a defense strategy probably quite early on, the 1972 ABM treaty will cease to have str ategic value to the U.S. It should be allowed to die timing of U.S. withdrawal from the treaty will be determined by the pace of technological innovation and the nature of Soviet behavior.

Treaty modifications, for example, could be negotiated with Moscow. As a practical matter, however, the ABM Treaty probably will not survive its 20-year review scheduled for 1992 The precise It would be desirable to extend constraints on offensive weapons Such constraints would make successive levels into the next centur y of active defense feasible at an earlier point in time and thus accelerate the defensive transition. Here too, however, Soviet resistance must be anticipated.

Soviet efforts to negate U.S. defenses through offensive force improvements will continue for s ome time. Gradually, however, it will become apparent that offensive forces are losing their military utility. As this occurs, Russian leaders may become more receptive to formulas aimed at major bilateral reductions in offensive forces.

Their receptivity would be encouraged if, as seems likely, their defensive systems were inferior to those of the U.S.; in such a situation, reductions in U.S. forces might be the only way of compensating for poor Soviet defensive technology.

Once the Soviets have agreed to give up offensive weapons to bolster the Performance of their defenses, the era of Mutual Assured Destruction bill end will then, for the first time in the atomic age, become feasible.

Serious consideration of nuclear disarmament 9TRANSITIONAL INSTABILI TIES The contention that a defensive transition will spark an unconstrained arms race making arms control impossible is based on a model: of Soviet-American interaction called llaction-reaction.l1 This model was developed originally within the McNamara De f ense Department in the 1960s to justify Mutual Assured Destruction. In brief, it argues that any defensive deployment will spawn an offensive reaction designed to preserve the adversaryls deterrent capability. Thus, any U.S. effort to build a defensive sh ield while ma.intaining the integrity of its offensive forces will provoke similar activities in the Soviet Union. The end result, in theory, is an unlimited and dangerous competition in both offensive and defensive weapons.

The action-reaction model assum es the race between offensive and defensive technologies is so close that successive increments of either in one country will require a response in the other country which in turn is sufficiently effective to require a counterresponse.

But this logic excl udes the possibility that advances in defensive technology might be so impressive as to preclude an effective offensive response. Since the objective of the SDI is to discover and develop such technologies, the long-term success of the program would rende r the reasoning behind an arms race irrelevant. The Soviets will not proliferate offensive forces unless they can reasonably expect thereby to negate U.S. defenses; if this expectation is justified, the U.S. will not build defenses in the first place warti m e, most notably to preempt U.S. retaliatory forces. Simply being able to obliterate American cities has little military utility because it invites responses in kind. While it is unrealistic to expect the SDI to develop impenetrable city defenses in this c e ntury it is quite plausible that U.S. defenses of its missile forces could be built that are simply beyond the capacity of Soviet offensive weapons to negate. If this were to occur, it is hard to see how proliferation of offensive capabilities would benef i t Soviet security. Consequently, with nothing to lose, Kremlin leaders might be quite willing to accept negotiated deep reductions in offensive forces Further, Soviet strategic forces have specific missions in CONCLUSIONS The problems presented by the tra n sition from today's reliance on nuclear offensive weapons to reliance on nonnuclear defense are manageable. Its benefits are indisputable. Deterrence will not last forever; the U.S. should begin planning the shift to an alternative posture now 10 The meas u res to manage the defensive transition comprise four Obiectives. The U.S. must identify its objectives clearly components: Since the defensive transition will take many years and encompass the tenures of several Administrations, the U.S. must specify both long-term and intermediate goals to keep the effort on track various components of strategic defense at various stages in the transition. Particularly, it must give more attention and resources to short-term technologies that might protect U.S. missiles a nd European military sites. Also, it must consider the roles that offensive forces will play in a mixed strategic force posture prior to their complete elimination.

Instabilities. The U.S. must anticipate potential instabilities that will accompany the tra nsition from offense dominance to defense dominance. By so doing, the U.S. can take steps to minimize the dangers they present Forces. The U.S. must think through the interrelation of the Arms Control. The U.S. must revise arms control policies so that th ey contribute to the aims of the defensive transition time, this will mean a complete reversal of the objectives that have characterized the SALT process.

The fundamental assumption on which recent U.S. strategic policies were founded, that deterrence some how would continue indefinitely, is unjustified and dangerous. Until America's present strategic posture is replaced by something more rational, U.S survival hangs by a thread spun of mere luck Over It is premature to start planning the precise mix of off e nsive and defensive weapons that the United States will need to maintain in its strategic force posture at successive stages in the defensive transition, because it is not yet clear what defensive technologies will prove viable or what the Soviet response s to those technologies will be. It is not too early, however, to reflect upon the appropriate organizational framework in which such a mixed force structure might operate. Moreover, it is useful to consider in advance how war plans and strategy might be i nfluenced by the coexistence of extensive offensive and defensive capabilities in the force structure of both superpowers.

Administration to address these issues therefore should be supported.

The on-going efforts of the Prepared for The Heritage Foundation by Loren Thompson Deputy Director National Security Studies Program Georgetown University 11 - Heritage Foundation Backgrounders on Strategic Defense Robert Foelber, Ifstrategic Defense: Avoiding Annihilation,Il No. 30 4 November 9, 1983.

C. Richard Whelan, "Wanted: A Space Policy to Defend America,Il No. 311, December 8, 1983 Robert Foelber and Brian Green, IISpace Weapons, The Key to Assured Surviva1,'l' No. 327, February 2, 1984.

Brian Green, Itstrategic Defense: The Technology That Makes It Brian Green The New Case for Civil Defense No. 377, August 29 Possible,I

No. 375, August 23, 1984 1984.

Loren Thompson, "Air Defense: Protecting America's Skies No. 379 September 13, 1984.

David B. Rivkin, Jr. and Manfred R. Ham, IIIn Strategic Defense Moscow Is Far Ahead," No. 409, February 21, 1985.

Anonymous, W.S.-Soviet Arms Accords Are No Bar to Reagan's Strategic Defense Initiative No. 421, April 4 1985 W. Bruce Weinrod and Manfred R. Ham, IIStrategic Defense t America's Allies,Il No 425, April 16, 1985.

Francis P. Hoeber, IIIn the Key Battle of Comparative, Costs, Strategic Defense Is A Winner," No. 442, July 5, 1985.

Thomas Krebs, llM l~ Many Problems in Countering A U.S. Strategic Defense System,Il No. 454, September 17, 1985 12