Anti-Satellite Weapons, Countermeasures, and Arms Control

Chapter 1 Executive Summary Contents

Page Introduction ...... 3 Principal Findings ...... 3 Comparison of Potential ASAT and Arms Control Regimes ...... 13 1. Existing Constraints...... 13 2. Comprehensive ASAT and Space-Based Weapon Ban ...... 14 3. ASAT Weapon Test Ban and Space-Based Weapon Deployment Ban 15 4. One Each/No New Types ...... 17 5. “Rules of the Road” for Space ...... 17 6. Space Sanctuary ...... 18 7. Space-Based BMD ...... 19 Treaties of Limited Duration...... 20

Tables Table No. Page l-1. Effect of Regimes on ASAT Development and Arms Control ., ...... ,13 l-2. Sensor Technology for Compliance Monitoring ...... 16 Chapter 1 Executive Summary

INTRODUCTION

For over two decades the United States and clear whether such survivability measures will the Soviet Union have used satellites for mil- be adequate to guard against the highly de- itary purposes. As a result of recent techno- veloped ASAT threats of the future. Another logical advances, military satellites will soon possible contributor to satellite survivability be able to play a more significant role in ter- is mutually agreed arms control. A judicious restrial conflicts. These space assets will be combination of certain arms control measures able to supply more types of information, more and unilateral satellite survivability measures rapidly, to more diverse locations. Some will might provide more security to U.S. military carry out target acquisition, tracking, and kill satellites than either type of measure alone. assessment functions, thus operating more At the same time, however, arms control directly than before as components of weap- measures which constrained the threat to U.S. ons systems. satellites would also constrain the ability of This growing military utility also makes sat- the United States to weaken Soviet military ellites attractive targets for opposing military capabilities by attacking their satellites in forces. Both the Soviet Union and the United time of war. In addition, limits on ASATS States have been developing anti-satellite would severely limit the kinds of ballistic mis- (ASAT) weapons. These weapons could weaken sile defense weapons that might be deployed the opponent’s military capabilities by depriv- in the future. (The subject of ballistic missile ing his forces of the services of some satellites. defense is dealt within a companion OTA re- The existing Soviet anti-satellite weapons— port, Balistic Missile Defense Technologies.) and future, potentially more effective ASATS This report explains the dilemmas facing –pose a growing defense problem for the U.S. policymakers and assesses the pros and United States. cons of some options for dealing with the chal- A variety of unilateral measures, passive lenge of anti-satellite weapons, particularly in and active, may improve the survivability of the light of projected future weapons tech- U.S. military satellites. At present, it is un- nology.

PRINCIPAL FINDINGS Current Soviet military satellites pose though not “weapons” themselves, support only a limited threat to U.S. military ca- and enhance the effectiveness of terrestrial So- pabilities, but future space systems will viet forces that would engage in direct com- pose a greater threat. bat. For example, if navigation satellites improve munition delivery accuracies, then fewer The Soviet Union currently uses satellites munitions are required to accomplish a given to perform a wide variety of tasks including missile launch detection, communications, objective. The growing military utility of sat- navigation, meteorological surveillance, pho- ellites has rekindled U.S. interest in ASAT tographic and radar reconnaissance, and col- weapons. lection of electromagnetic intelligence (e.g., Some Soviet satellites already supply lim- radar emissions). Many of these satellites, al- ited targeting information to other terrestrial

3 4

assets. The Administration has expressed its These options include nondestructive as well concern about: as destructive measures; those presented below are not mutually exclusive. . . . present and projected Soviet space systems which, while not weapons themselves, ● Possible nondestructive responses to So- are designed to support directly the viet MILSATs: U. S. S.R. ’S terrestrial forces in the event of –Force Augmentation: U.S. combat or a conflict. These include ocean reconnais- support forces could be increased to sance satellites which use radar and elec- counter the increase in effectiveness tronic intelligence in efforts to provide targeting data to Soviet weapon platforms which Soviet forces could derive from which can quickly attack U.S. and allied sur- use of military satellites. Force augmen- face fleets. ’ tation is often, but not always, more costly than other means of mitigating At present Soviet radar (RORSAT) and elec- the threat posed by Soviet military sat- tronic intelligence (EORSAT) ocean reconnais- ellites. sance satellites pose only a limited threat to –Passive Countermeasures: By using U.S. and allied surface fleets. RORSATS and passive measures to conceal or disguise EORSATS are typically deployed at altitudes their identity and nature, U.S. forces and inclinations which offer limited observa- could reduce the utility of Soviet recon- tion range. Although the observation “swath” naissance satellites. For example, as- of these satellites will eventually cover most sets now detectable by radar might be of the Earth, if only one or two of these satel- redesigned to reflect radar signals only lites are operational-as has been customary weakly in order to evade detection by in peacetime-then a ship would be exposed radar satellites, or radio silence might to observation only intermittently and might be practiced, or covert signaling tech- successfully evade the satellite. The Soviet niques used to prevent detection by sat- Union could increase the number of deployed ellites that collect signals intelligence. RORSATS and EORSATS, thereby making –Electronic Countermeasures and Electro- evasion more difficult. Other countermeasures optical Countermeasures: Electronic coun- exist which could further reduce the threat termeasures such as “jamming” (i.e., posed by these satellites, but such measures overloading enemy receivers with might not be available to merchant resupply strong signals) and “spoofing” (i.e., vessels operating during a protracted non- sending deceptive signals) could be used nuclear conflict. to interfere with satellite functions. In the future, sophisticated communication, Electro-optical countermeasures such navigation, and surveillance satellites are as “dazzling” (temporary “blinding”) or likely to play a greater role in all levels of ter- spoofing optical sensors are also avail- restrial conflict. This will increase the incen- able. However, these countermeasures tive for both the United States and the Soviet —especially spoofing—require detailed Union to develop and deploy ASAT weapons. knowledge of the satellite systems (e.g., operational frequencies, receiver sensi- tivity, etc.) against which they are Possible responses to the threat posed directed. by Soviet military satellites are numer- ● Possible Destructive Responses to Soviet ous and diverse. MILSATs: A variety of options are available to miti- –Inadvertent But Inherent ASAT Capa- gate the threat to U.S. and allied security bilities: The inherent ASAT capabilities posed by Soviet military satellites (MILSATS). of nuclear weapons such as ICBMS and SLBMS could be used to destroy low- ‘President Ronald Reagan, Report to the Congress: U.S. Po]- altitude Soviet satellites; with some icy on ASAT Arms Control, Mar. 31, 1984. modifications, these weapons might 5

also be used to attack satellites at Although national utility for space system higher altitudes. Some types of non- support is difficult to assess precisely and nuclear interceptors (e.g., that demon- meaningless to compare between nations, it strated in the U.S. Army’s 1984 Hom- is apparent that the United States is more de- ing Overlay Experiment (HOE)) which pendent on MILSATS to perform important might eventually be developed and de- military functions than is the Soviet Union. ployed for BMD purposes, would have The United States has global security commit- some inherent ASAT capability. Fi- ments and force deployments, while the Soviet nally, any highly maneuverable space- Union has few forces committed or deployed craft capable of noncooperative rendez- outside the borders and littoral waters of mem- vous—e.g., the U.S. Space Shuttle—has bers of the Warsaw Treaty Organization and some ASAT potential. Cuba. The United States has corresponding —Planned ASAT Weapons: When oper- requirements for global and oceanic command ational, the current USAF MV ASAT and control communications (C3) capabilities weapon will be able to destroy Soviet and relies largely on space systems to provide military satellites in low-Earth orbit. these requirements. The Soviet Union, on the –Advanced ASAT Weapons: Space- or other hand, can rely on landline communica- ground-based directed-energy weapons tions systems and over-the horizon radio links or advanced kinetic-energy weapons for many of its C’ needs. Satellite communi- could be developed that would be able cations links are used by the Soviet Union but to destroy Soviet satellites beyond the are not as essential as those of the United range of existing or planned U.S. ASAT States. In addition, the Soviet Union has weapons. greater capability to reconstitute satellites which are lost in action; hence even to the ex- The United States is now more depen- tent the Soviet Union is dependent on space dent on satellites to perform important system support, it is less dependent on indi- military functions than is the Soviet vidual satellites for some functions. The Union. United States also has fewer alternative ter- In choosing between ASAT weapon devel- restrial means for collecting intelligence than opment and arms control, one wishes to pur- does the Soviet Union, which can exploit the sue that course which makes the greater con- freedom and openness of U.S. society for this tribution to U.S. national security. This is purpose. often characterized as a choice between developing a capability to destroy Soviet satellites Soviet ASAT capabilities threaten U.S. while assuming U.S. satellites will also be at military capabilities to some extent now risk, or protecting U.S. satellites to some ex- and potentially to a much greater extent tent through arms control while forfeiting ef- in the future. fective ASAT weapons. The better choice could, in principle, be identified by comparing The Soviet Union tested a coorbital satel- the utility which the United States expects to lite interceptor system from 1968 until its self- derive from its military satellites with the dis- imposed moratorium of August 1983. The utility which the United States would expect Reagan Administration considers this ASAT to suffer from Soviet MI LSATS during a con- system to be operational. The interceptors are flict. Such a comparison-although possible in believed to be capable of attacking satellites principle–is made exceedingly difficult by the at altitudes of up to 5,000 kilometers, depend- number of conflict scenarios which must be ing on their orbital inclination. At present considered and by the lack of consensus or offi- there appear to be only two launchpads for So- cial declaration about the relative likelihood viet coorbital interceptors, both located at and undesirability of each scenario. Tyuratam. 6

attractive targets. Both the United States and the Soviet Union have been developing anti-satellite (ASAT) weapons

The existing Soviet ASAT weapon may be The current Soviet interceptor and the effective for negating low-altitude U.S. mili- booster that it has been tested with cannot tary satellites, such as are used for navigation reach critical U.S. early warning and commu- (Transit), meteorological surveillance (Defense nication satellites in high orbits. If the Soviet Meteorological Support Program satellites), ASAT weapon were mated with a larger boost- and other purposes. Assistant Secretary of De er—a procedure which has yet to be tested— fense Richard Perle has stated: it might be able to reach these U.S. satellites. We believe that this Soviet anti-satellite ca- In addition to the coorbital interceptor, the pability is effective against critical U.S. sat- Soviet Union is testing ground-based lasers ellites in relatively low orbit, that in wartime which the Reagan Administration believes we would have to face the possibility, indeed have ASAT capabilities. The U.S. Department the likelihood, that critical assets of the of Defense estimates that the U.S.S.R. could United States would be destroyed by Soviet test a space-based laser within the decade.3 anti-satellite systems. . . . If, in wartime, the Soviet Union were to attack critical satellites Advanced directed-energy weapons such as on which our knowledge of the unfolding con- lasers and particle beam weapons–if devel- ventional war depended, . . . we would have oped and deployed—could give the Soviets an little choice but . . . to deter continuing at- “all altitude, “ “instantaneous kill” capability. tacks on our eyes and ears, without which we As the United States increases its reliance on could not hope to prosecute successfully a space systems to perform vital military func- conventional war. z tions (e.g., the MILSTAR communication satellite system), an increase in Soviet ASAT ca- ‘Statement of The Honorable Richard Perle, Assistant Sec- pabilities could create a significant threat to retary of Defense (International Security Policy), in Hearings U.S. national security. before the Subcommittee on Strategic and Theater Nuclear Forces of the Senate Comm”ttee on Armed Services: Review of the FY 1985 Defense Authorization Bill, Mar. 15, 1984 ‘U.S. Department of Defense, Soviet Military Power, 1985, [S.Hrg. 98-724, Pt. 7., p. 3452]. p. 44. 7 .

Aside from its intentional ASAT capabil- tional or nuclear explosive charge, a space ities, the Soviet Union could currently attack mine would destroy its quarry almost ins- low-altitude satellites with its nuclear ABMs, tantly on command or (if salvage-fused) ICBMs, and SLBMS. With some modification, when attacked or disturbed. these nuclear assets might also be used to at- High-Power Radio-Frequency Weapons: tack satellites in higher orbits. Current Soviet These would be devices capable of produc- spacecraft (i.e., Soyuz, Salyut), because of their ing intense, damaging beams of electro- limited maneuter and rendezvous capabilities, magnetic radiation that could be used to do not hate a significant ASAT potential. Fu- jam communication and radar systems at ture Soviet spacecraft, such as the expected low power levels or to overload and burn Soviet “Shuttle” and space plane, will have out satellite electronics at higher power greater inherent ASAT capabilities. The So- levels; viets also have the technological capability to High-Energy Laser Weapons: High-ener- conduct electronic warfare against space gy lasers may eventually be capable of systems. producing intense, damaging beams of electromagnetic radiation that could jam Several technologies on the horizon optical communication and sensor sys- could lead to a new generation of highly tems at low power levels or cause perma- capable ASATS. nent damage at higher power levels. Ground-based lasers would have infre- ‘1’he following advanced ASATS could be de- quent opportunities to attack satellites \“eloped and deployed b~~ either the United but, unless attacked themselves, could States or the Soviet Union: shoot inexpensively and repeatedly. ● 5’pace Alines.a These would be deployed Space-based reflectors could also be used within lethal range and would continu- to relay laser beams from ground-based ousl~’ trail their target. Using a conven- lasers to their targets. Spacebased lasers

,/’

Artist’s conception of high-energy laser facility at the Sary Shagan test facility in the Soviet Union,

H!gh-energy lasers may eventually be effective ASAT weapons, Ground-based lasers would have Infrequent opportunities to attack satellites, but, unless attacked themselves. could shoot inexpensively and repeatedly, 8

might be able to attack several satellites riety of ASAT weapons and will be par- in quick succession; space-based X-ray ticularly economical for the protection lasers might be able to attack several sat- of small satellites capable of being imi- ellites instantly and simultaneously. tated by small, cheap decoys. Combina- ● Neutral Particle Beam Weapons: Power- tions of these passive responses—e.g., ful particle accelerators, similar to those decoys for “dark” spare satellites– now used in scientific research, might could offer even greater protection than eventually be developed which could de- individual measures alone. stroy the hardened electronics of a —Active Countermeasures: Active coun- spacecraft. termeasures may be destructive or non- ● Kinetic-Energy Weapons: Space- or destructive. Destructive countermeas- ground-based kinetic-energy weapons ures could include giving satellites a (similar to the current U.S. MV ASAT) self-defense capability or providing crit- would probably be small, homing vehicles ical satellites with an escort defense. that destroy their target by colliding with Nondestructive countermeasures might it at extremely high velocities. include electronic countermeasures and electro-optical countermeasures such as jamming. Attacking Soviet ASAT con- Possible U.S. responses to the Soviet trol facilities is also a potential-though ASAT threat are numerous and diverse. dangerous— active countermeasure. The United States could respond to the –Deterrence: The Soviets might be de- threat posed by the Soviet ASAT threat in terred from attacking U.S. satellites if several ways; both unilateral and diplomatic the United States declared its willing- options are available. ness to retaliate for attacks on U.S. space assets. Such retaliation could be ● Possible unilateral responses to Soviet against Soviet space assets, in which ASATS: case the United States would need a ca- –Reduce Dependence on Military Satel- pable ASAT weapon, or it could be lites: No matter what satellite surviv- against Soviet terrestrial assets. The ability or arms control measures are former alternative assumes that the taken, there will always be some risk Soviets value the preservation of their that critical satellites can be destroyed satellites at least as highly as they or rendered inoperable. The United value the destruction of U.S. satellites. States must exercise caution in the ex- The latter alternative, of course, carries tent of its reliance on space assets to a greater risk of uncontrolled escalation perform tasks essential to the national if deterrence should fail. security. Nonetheless, some space sys- –Keep-Out Zones: The United States tems perform vital military functions could declare and defend protective which cannot be duplicated—or can be zones around critical satellites. duplicated only imperfectly-by terres- Defended keep-out zones could offer sig- trial systems. nificant protection against current –Passive Countermeasures: Passive ASAT weapons for some satellites. This countermeasures such as hiding, decep- subject is discussed in detail below. tion (use of decoys), evasion (maneuver- Possible diplomatic responses to Soviet ing), hardening (making satellites more ASATS: durable), and proliferation (adding more –Arms Control; The United States, the satellites) all offer significant protection Soviet Union, and other spacefaring na- from the current and perhaps future So- tions could negotiate limitations on the viet A SAT weapons. Decoys would testing, deployment, or hostile use of probably be effective against a wide va- anti-satellite systems. 9 . —

–Rules of the Road: The United States, neutral particle beam weapon could cost more the Soviet Union, and other spacefar- than it would to scale up the weapon to pene- ing nations could negotiate restrictions trate the shielding, and such a weapon could on potentially provocative activities in slew its beam quickly enough to make evasion space, such as unexplained close ap- infeasible. With such a weapon it might be as proaches to foreign satellites or irradi- economical to damage spare satellites as they ation of foreign satellites with low- are brought “on line’ as it would be to dam- power directed-energy beams. With age initially operational satellites. such agreed restrictions in force, these activities would justify defensive or Active measures, such as “shoot-back” with retaliatory measures. a weapon of longer effective range, could provide protection against some A SAT weapons but not against weapons such as space mines Of the future ASAT weapons now fore- or single-pulse lasers which could destroy sat- seeable, those which would be most effec- ellites instantly and without warning. How- tive if used in a preemptive or aggressive ever, it might not be economical to attack sat- surprise attack would be space-based and ellite systems composed of many small, cheap therefore subject to attack by similar satellites—and possibly decoys as well—with weapons. expensive advanced ASAT weapons. Such sat- Preemptive attack would be an attractive ellites could perform a number of important countermeasure to space-based ASAT weap- functions (e.g., communication or navigation) ons. If each side feared that only a preemp- without encouraging a proliferation of ad- tive attack could counter the risk of being vanced weapons to attack them. Therefore, al- defeated by enemy preemption, then a crisis though it would be difficult to protect individ- situation could be extremely unstable. While ual satellites, satellite systems performing salvagefusing, if it proved practicable, would some critical functions might retain a fair de- diminish this risk, it would create a risk of gree of survivability. space war breaking out by accident. For example if a meteoroid destroyed a satellite, it might set off a chain reaction of salvage fus- ing which would destroy all satellites. To the A commitment to satellite survivability is important whether or not ASAT de- extent that protection was sought through velopment, or arms control, or both, are “shoot-back” rather than “shoot-first” tactics, a premium would be placed on having the big- pursued. gest and best ASATS deployed, which could The United States should place more empha- lead to an intense arms race. sis on means to ensure the survivability of critical military satellites and, particularly, their associated ground stations and data links, Foreseeable passive or active counter- regardless of whether ASAT limitations are measures may be inadequate to guaran- agreed upon. The existence of non-ASAT tee the survival of large inilitary satellites weapons (e.g., ICBMS, ABMs) and space sys- attacked by advanced ASAT weapons. tems (e.g., maneuverable spacecraft) with Passive or active countermeasures might some inherent ASAT capability makes it im- have only limited effectiveness against very possible to ban the ability to attack satellites. advanced ASAT or BMD weapons. For exam- Therefore, even under the most restrictive ple, it might be uneconomical to rely on pas- ASAT arms control regime, programs for sat- sive measures to protect large and expensive ellite survivability and countermeasures must satellites from a powerful neutral particle be pursued. In the absence of arms control beam weapon. Shielding satellites against a limitations on ASATS, ensuring satellite sur- 10

viability will be a more demanding task since United States might announce a “no first highly capable directed-energy ASAT weap- strike but possible first use’ policy for the em- ons or space mines could be deployed. ployment of ASAT weapons as it has for the employment of nuclear weapons. In the absence of restrictions on the development or deployment of ASAT weap- If defensive satellites (DSATS) are deployed ons, satellite survivability can be en- by the United States to defend its satellites, hanced if the United States is willing to or if certain satellites are given self-defense ca- negotiate or declare keep-out zones and pabilities, the United States would have to de is able thereafter to defend such zones cide under what circumstances it would use against unauthorized penetration by for- these assets and whether it wished to publicly eign spacecraft. announce this employment policy. The United Although passive or active countermeasures States might declare in advance that it would alone may be insufficient to protect satellites, fire at satellites suspected of being ASATS if if combined with keep-out zones they could of- they approached U.S. satellites within possi- fer a significant degree of protection from cer- bly lethal range. However, such a declaration tain ASAT weapons. Without keep-out zones would have an uncertain legal status and space mines could be predeployed next to all might generate considerable political opposi- critical military space systems. A keep-out tion from both spacefaring and non-space- zone of sufficient size would reduce the effec- faring nations. tiveness of such weapons. However, advanced, directed-energy or kinetic energy ASAT weap- Certain arms control provisions would ons may be able to function effectively even reduce the probability that advanced outside very large keep-out zones. ASATS will be developed or deployed. However, arms control could not guaran- tee the survival of U.S. satellites attacked Should ASAT development be pur- by residual or covert Soviet ASAT sued, the United States will need to for- weapons. mulate an employment policy. Arms control provisions, such as a ban on At present, no clear consensus exists among all testing of all systems “in an ASAT mode,” those Administration military space policy would reduce the likelihood that the Soviet analysts and executives interviewed by OTA Union could successfully develop and deploy on the conditions under which the United advanced, highly capable ASAT weapons. The States would attack foreign satellites or on the categories of weapons eliminated might in- manner in which it would retaliate for an at- clude space mines capable of “shadowing” val- tack on U.S. satellites. If the United States uable military assets in any orbit, directed- continues with its ASAT development and de- energy weapons with kill radii of hundreds to ployment plans, it will be necessary to formu- thousands of kilometers, and advanced kinet- late an employment policy. ic-energy weapons. In the absence of an agree- If the United States wishes to enhance the ment limiting their development, each side deterrent value of its ASAT weapons, it may would have a strong incentive to seek contin- choose to publicize certain aspects of its em- ually more effective means to attack threat- ployment policy. It might, for example, prom- ening satellites and to defend valuable assets. ise that the United States would not use its In the absence of adequate countermeasures, ASAT capabilities in an aggressive or preemp- the “instantaneous kill” capability of some ad- tive first strike but might use them in a defen- vanced ASATS might be destabilizing in a cri- sive or retaliatory reaction to an attack sis, because they would give each side an in- against the United States or its allies, even if centive to “shoot first” or else risk the loss U.S. satellites were not attacked. That is, the of its space assets. 11

Photo cred(l Lockheed Photo cred{t U S Deparfment of Defense Launch of U.S. Homing Overlay Experiment (HOE) to Artist’s conception of the Soviet GALOSH ABM test nonnuclear anti-ballistic missile technology, interceptor currently deployed around Moscow.

ABM interceptors may have some inherent ASAT capabilIties, ABMs, as well as ICBMS and SLBMS, present a threat which may not be easily resolved through arms control,

A ban on testing weapons in an A SAT mode ing satellites which might be booby-trapped. would be less effective at reducing the threat However, the range, effectiveness, and re- posed by weapon systems with inherent action time of even advanced maneuverable ASAT capability and by the existing Soviet spacecraft not designed as weapons would be ASAT weapon. ICBMS, SLBMS, and ABM in- substantially less than those of intentional terceptors with nuclear payloads are examples ASAT weapons. Although the development of of systems with residual ASAT capability. Al- maneuverable spacecraft would not be in- though these systems lack the kind of preci- hibited by most ASAT testing limitations, sion guidance necessary to actually collide some limits could be placed on operating them with a satellite, the long-range destructiveness “in an ASAT mode. ” of their nuclear payloads makes them poten- Arms control provisions might substi- tially effective ASATS. The Shuttle’s recent tute for passive and active countermeas- success at retrieving satellites strongly sug- ures in reducing the threat posed by gests the ASAT potential of future maneuver- ASAT weapons, but arms control would able spacecraft, although costly vehicles like be more effective if combined with coun- the Shuttle would probably not risk approach- termeasures. 12

U.S. satellites can be protected either by in- have excellent ASAT capabilities, any ASAT creasing their survivability or by reducing the limitation or test ban would almost certainly threat posed by Soviet ASAT weapons. Pas- impede BMD development. Conversely, tech- sive or active countermeasures are designed nology development ostensibly for advanced to do the former while arms control provisions ASAT systems might provide some limited would hopefully do the latter. In considering BMD capabilities, or, at minimum, informa- the advantages and disadvantages of ASAT tion useful in BMD research. arms control, ASAT development, and coun- Some available unilateral actions have clear termeasures, it is important to consider them benefits: in packages. A combination of arms control provisions and passive countermeasures, for ● Deployment of attack sensors on valuable example, or of passive countermeasures and satellites in order to provide information active countermeasures, could provide greater to support a retaliation decision; security than each component of such a pack- ● Deployment of a space-based, space sur- age might provide alone. veillance system in order to provide information to support verification of compliance with future arms control agreements; The benefits of most ASAT limitations to provide warning information required conflict with the benefits of ASAT exploi- for effective evasion or dispensing of de tation. coys; to support a decision to retaliate in Although ASAT arms control might pre- the event of an attack; and to provide in- vent the Soviet Union from developing ad- formation required for the targeting of 4 vanced, highly capable ASAT weapons, it ASAT/DSAT weapons ; would also place a similar restriction on the ● Hardening of military satellites against United States. Therefore, although U.S. sat- nuclear effects to a modest degree in or- ellites might be less vulnerable to ASAT at- der to preclude “cheap kills” by nuclear- tack, the United States would have to give up armed ICBMS, SLBMS, or ABMs; the ability to strike at Soviet satellites which c Development. or maintenance of electronic threaten U.S. and allied forces. Although arms countermeasures and electro-optical coun- control might prevent an expensive and poten- termeasures, which would be relatively tially destabilizing arms race in space, it would cheap, useful at all conflict levels, and un- also limit the ability of the United States to likely to be prohibited by arms control use its comparative advantage in advanced agreements. technology to protect U.S. satellites and place threatening Soviet satellites at risk. The ASAT weapon under development in the Not all arms control regimes are inconsist- United States is sufficient to meet the threat ent with ASAT development or deployment. posed by current, low-orbit Soviet military sat- “Rules of the road” for space–e.g., negotiated ellites. keep-out zones—might be pursued simultane- Should the United States decide that it is ously with ASAT research, testing, and de- in our national security interest to deploy ployment. ASAT weapons, the current MV program and, potentially, interceptors based on the recently Effective ASAT arms control would tested HOE technology, are sufficient to re- likely place significant restrictions on the spond to the threat posed by existing Soviet testing and deployment of future ballis- military satellites in low orbit. The current tic missile defense systems. U.S. ASAT could be made even more effective by the addition of a spac~based space surveil- There is considerable overlap between BMD 4Because of its usefulness, such a surveillance system would and ASAT technologies. Since even a poor bal- bean attractive target for a Soviet ASAT attack. The ultimate listic missile defense system would probably utility of such a system, therefore, hinges on its survivability. 13 lance system to aid the process of targeting altitudes out of reach of the U.S. MV. Should and/or additional basing facilities. this happen, it would provide a strong incentive to extend the MV’S capabilities by add- Many of the functions performed by Soviet ing a larger booster or to develop a newer, military satellites may eventually be per- more capable ASAT system. formed by more capable satellites orbiting at

COMPARISON OF POTENTIAL ASAT AND ARMS CONTROL REGIMES

There are widely varying views about the of A SAT and BMD technology development, wisdom of deploying weapons which are to satellite survivability, and arms control. Each operate in space or against space objects. This regime is constructed so that it is different fact, combined with more general concerns from the other regimes and so that it contains about the Soviet military threat and the elements which might reasonably be expected dangers of the U.S./Soviet arms race, has to co-exist in the same proposal. made it difficult to forge a national consensus on the subject of ASAT weapons. Some peo- 1. Existing Constraints ple oppose A SAT weapons as a matter of principle because these weapons would operate in The first regime is defined by treaties and space or because such developments would agreements presently in force; these are the contribute to the arms race. Others believe the Limited Test Ban Treaty, the Outer Space benefits of ASAT weapons are outweighed by Treaty, and the Anti-Ballistic Missile Treaty. the risk they pose to current U.S. space sys- The existing international legal regime pro- tems, which are seen as essential for maintain- hibits the use of A SAT capabilities except in ing U.S./Soviet strategic stability. Still others self-defense, the testing or deployment of see the development of A SAT and BMD weap- space-based weapons with BMD capability, ons as a means to exploit U.S. technological and the testing or deployment in space of nu- advantages to enhance U.S. power, reduce the clear space mines or ASATS that would re- threat of conflict and global nuclear war, and quire a nuclear detonation as a power source. reduce the damage done by such a war should it ever occur. Table 1-1 .—Effect of Regimes on ASAT Development In its analysis, OTA has attempted to take and Arms Control into consideration this range of viewpoints and, to the greatest extent possible, show how Restrict with Develop ASAT arms control weapons it leads to a range of policy options. Many of Existing constraints . . . . . No Yes the choices that will be made over the next sev- Comprehensive ASAT eral years will require a delicate balancing of and space-based strategic, economic, and political considera- weapon ban ...... Yes No Test ban and space- tions. There is little doubt that reasonable per- based weapon ban . . . Yes Yes/Noa sons can and will disagree as to the most One each/no new types . . Yes Yesb Rules of the road ...... Yes Yesc appropriate nature of this balance. c Space sanctuary ...... Yes Yes Seven international legal regimes and cor- Ballistic missile defense . No Yes alrr thts regime ASAT weapons could be developed, tested, and deployed on Earth responding military postures are considered but not In space The United States could pursue ASAT development with!n the critically below. Each of these regimes is in- bounds of the treaty, or it could forego ASAT development entirely bAll ASAT weapon5 other than “current types” could not be tested or cledoyed tended to facilitate assessment of the effective In space c Development and deployment optional but strongly supported by aciwcates Of ness and desirability of different combinations this regime 14

With these few exceptions, all other ASAT research could be conducted without first hav- weapon development and deployment activi- ing to modify or withdraw from the ABM ties would be allowed. It is, therefore, permis- Treaty. sible for the United States and the Soviet Some view advanced ASAT research as dan- Union to develop and deploy coorbital inter- gerous for this very reason. They argue that ceptors (like the current Soviet system), direct- such research will gradually erode the useful- ascent interceptors (like the current U.S. sys- ness of the ABM Treaty, thereby precipitat- tem), terrestrial or space-based lasers, space- ing a defensive and offensive arms competi- based neutral particle beam weapons, and tion on Earth and in space. Rather than weapons based on maneuvering spacecraft. protecting satellites, a competition in space In the current regime both the United weapons might severely reduce their military States and the Soviet Union could develop, utility. Under conditions of unrestrained com- test, deploy, and use such passive counter- petition, security might be purchased, if at all, measures as hiding, deception, evasion, only at the price of a substantial and sustained hardening, and proliferation. Active, non- commitment to the development of increas- destructive defenses, such as electronic or ingly sophisticated offensive and defensive electreoptical countermeasures, would also be space weapons. In such an environment, en- allowed. Active, destructive defenses, such as suring the survivability of satellites would re- shoot-back or DSATS, would be allowed as quire more than simple hardening or evasion. long as they did not violate any of the trea- Costly measures might have to be taken such ties enumerated above. as the deployment of precision decoys, predeployed spares, or acquiring the ability to The primary advantage of the current re- quickly reconstitute space assets. Satellites ca- gime is that it allows the almost unrestrained pable of defending themselves or a compan- application of U.S. technology to the twin ion satellite might also have to be developed problems of protecting U.S. satellites and plac- and deployed. ing threatening Soviet satellites at risk. Un- der this regime, the United States would be Should space-based weapons such as space free to use its comparative advantage in ad- mines or directed-energy weapons be deployed, vanced technology to keep pace with expected these might be capable of the almost instan- developments in Soviet ASATS and other mil- taneous destruction of a large number of crit- itary satellites. Advanced U.S. ASATS might ical satellites and ASATS. This could force na- discourage the development of more capable tions into a situation in which they must “use Soviet space systems designed to place U.S. or lose” their own pre-deployed space weap- terrestrial assets at risk. In addition, the ons. This might supply the incentive to esca- United States would be free to respond to So- late an otherwise manageable crisis. viet A SAT weapons with increasingly sophisticated defensive weapons and countermeas- 2. Comprehensive ASAT and ures, thereby reducing the probability that the Space-Based Weapon Ban Soviets would ever use their intentional or inherent ASAT capabilities. A comprehensive ASAT and spacebased weapon ban would require the United States In the existing regime, research and devel- and the Soviet Union to agree to forgo the pos- opment on new ballistic missile defense tech- session of specialized ASAT weapons, the nologies can also proceed without the con- testing—on Earth or in space—of specialized straints that might be imposed by certain ASAT capabilities, the testing in an “ASAT ASAT arms control regimes. Testing of ad- mode’ of systems (e.g., ICBMS or ABMs) vanced ASATS could provide valuable information that would contribute to the develop- ‘Testing in an “A SAT mode” would include tests of ground- ment of very capable BMD systems. There- , air-, sea- or space-based systems against targets in space or fore, some types of generic space-weapon against points in space. 15 which have inherent ASAT capabilities, and an absolute ban on possession might make it the deployment in space of any weapon. Such less likely that the current generation of a regime would require the U.S.S.R. to destroy ASAT weapons could be upgraded and held all of its coorbital interceptors and the United in readiness in significant numbers. States to destroy all of its direct-ascent inter- 6 However, if the United States can only be ceptors. confident that the Soviets are complying with Although this regime contains the most far- a treaty to the extent we can verify compli- -reaching arms control provisions, it would ance, then the United States would not have have the disadvantage of being the most dif- confidence that this regime offered any greater ficult to verify. Unlike an ASAT test ban and protection to our satellites than would a test space-based weapons ban regime, a compre- ban and space deployment ban. hensive ban would prohibit possession and testing of A SAT weapons on Earth.7 Because 3. ASAT Weapon Test Ban and the current Soviet coorbital interceptor is a Space-Based Weapon Deployment Ban relatively small spacecraft launched on a much larger, generaI-purpose booster, the Soviet In this regime, in addition to adhering to Union could maintain and perhaps even ex- treaties and agreements presently in force, the pand its ASAT force without the the United Soviet Union and the United States would States gaining unambiguous evidence of a vio- agree to forgo all testing in an “A SAT mode” lation. and the deployment of any weapon in space. Such a ban would not only prohibit the test- Since the United States might agree to a ing of both current and future ASAT systems comprehensive ASAT ban only after consid- but would also place similar restrictions on erable domestic political friction over ques- BMD systems with ASAT capabilities. This tions of compliance and verification, it is im- regime would not ban terrestrial research on portant to consider how such a ban might ASAT or space-based weapons and would not make a greater contribution to U.S. national attempt to ban their possession. Therefore, if security than a ban on ASAT testing and it were judged to be desirable, ASAT and spacebased weapon deployment (discussed be BMD weapons could be developed (though not low). The purpose of both bans would be to pre tested in space) and held in readiness on Earth. vent the use of ASATS, or, at minimum, to reduce the probability that an ASAT attack In a test ban regime, the passive counter- would be effective. An ASAT test ban would measures and nondestructive active counter- primarily affect weapons reliability, while an measures that were discussed in the “existing ASAT possession ban, if observed, would af- regime” could still be developed and employed. fect both availability and reliability. It is con- Destructive active countermeasures such as ceivable that the risk posed by possible ille- “shoot-back” or DSATS could not be tested gal Soviet use of ASAT weapons might be or deployed but could be developed and held somewhat lower in a regime in which the in readiness. Soviets could not lawfully possess ASAT Although a ban on testing in an “ASAT weapons. Presumably, the inability to overtly mode” would not eliminate all threats to sat- possess ASAT weapons would diminish one’s ellites, it would reduce the cost and complex- ability to use them effectively. Furthermore, ity of ensuring a reasonable level of satellite survivability. The United States would still 6Such an agreement might resemble the draft treaty proposed benefit from ‘hardening’ its satellites and de- to the United Nations by athe U.S.S.R. in August of 1983, except that draft also bans the testing or use of manned space- ploying spares and decoys, but the more craft for military purposes. See U.N. Document A138/194, Aug. elaborate, expensive, precaution of developing 23, 1983. and deploying DSATS would be prohibited 7A comprehensive ban would not ban systems with inherent ASAT capabilities, such as ICBMS, ABMs, and maneuvera- and, indeed, less attractive. In the absence of ble spacecraft, reliable, effective ASATS, satellites would pre 16 -.

Table l-2.—Sensor Technology for Compliance Monitoring

Prohibitable action Observable .— sensors ASAT attack: Attack sensors: KEWa impact ...... acceleration accelerometers Pulsed HELb irradiation . . . acceleration accelerometers Continuous H EL irradiation ...... heating thermistors NPBC irradiation ...... ionization ionization detectors Keep-out zone penetration . . . position of thermal radiation source (ASAT) space-based LWIRd thermal image~ f Interception test ...... positions of thermal radiation sources space-based LWIR thermal imageP r (ASAT and target) NPB ASAT operation ...... thermal radiation from ASAT space-based LWIR thermal imagere HEL ASAT operation ...... thermal radiation from ASAT space-based LWIR thermal image~ f Irradiation of target with NPB ...... gamma radiation from target gamma-ray spectrometer Irradiation of target with pulsed HEL ...... thermal radiation from target space-based LWIR thermal imager Irradiation of target with pulsed HEL ...... reflected radiation from target space-based multi spectral imager Irradiation of target with continuous HEL ...... position of thermal radiation source (target) space-based LWIR thermal imager Irradiation of target with continuous HEL ...... reflected radiation from target space-based multi spectral imager Nuclear explosive aboard satellite ...... gamma radiation from fissile or fusile gamma-ray spectrometer (and optional nuclei activated by cosmic radiation or by particle beam generator) particle — beams a/([email protected] weapon bHtgh.energy laser cNeutral. Darticle beam dl-ong.w~velength Infrared eThe LWlR telescope on the Infrared A~trOnOnll~al satellite (lRAs) OXOMpliflOS demonstrated space-based tflerrnal IMager technology, this Instrument IS described in .4strophys/ca/ Journal, 278 (1, Pt. 2), L1 -L85, Mar 1, 1984 (Spectal Issue on the Infrared Ast ronomlcal Satelllte) fRadar and Passive radio direction.finding methods could also be useful for tracking, tf h!dlng measures are not employed b the Penetratln9 spacecraft LWIR tracking IS emphasized here because it is difficult to counter by such measures gA target irradiated by a high-energy neutral panicle beam will emit gamma rays, neutrons, and other observable particles, Just as It Will, at a slower rate, when bombarded by natural cosmic rays These gamma rays could be detected by a gamma-ray spectrometer such as those which have been carried by Sowet Venusian and lunar landers and by U S NASA Ranger and Apollo spacecraft (NASA report SP-387, pp 3.20 ) sumably be of greater utility since the United on the HOE technology) since a “no test” ban States might have higher confidence that they would not prohibit ASAT possession. How- would be available when needed. ever, confidence in the operational capability of both the U.S. and Soviet ASAT systems Relative to the existing regime, the primary would degrade over time without continued advantage of a regime banning testing of operational testing. ASAT capabilities and deployment of space- based weapons would be that highly valued There would be two important disadvan- U.S. satellites in higher orbits–e.g., the future tages to this regime. First a ban on testing in MILSTAR system–could be protected with an “A SAT mode” and deploying space-based some confidence from advanced A SAT weap- weapons would not offer absolute protection ons, especially if protected as well by passive for satellites; there would remain some possi- countermeasures. The fact that advanced bility that an untested–or covertly tested– ASATS could not be overtly tested would re- advanced ASAT, if suddenly deployed and duce the probability that they would be devel- used, might actually work well enough to over- oped and deployed. If they were developed and come passive countermeasures. Second, with- used without prior testing, a test ban would out an ASAT weapon the United States would reduce the probability that they would be suc- lack a fully tested means to attack threaten- cessful. ing satellites. The United States would, therefore, have to place greater reliance on coun- As in the existing regime, the United States termeasures to protect its terrestrial assets. could retain a capability to attempt to negate It is unclear whether countermeasures alone low-altitude Soviet satellites with its MV will be able to keep pace with the threat posed ASAT (or, possibly, with interceptors based by advances in military satellites. 17

Depending on one’s viewpoint, an additional A primary disadvantage of a “no new advantage or disadvantage of this regime is types” regime would be that allowed (i.e., that the testing of some types of advanced tested, nonnuclear) U.S. ASAT weapons would BMD weapons would be prohibited. This pro- be inadequate to negate threatening Soviet hibition might even include some ground- satellites if such satellites were moved to based BMD weapons such as the U.S. HOE higher orbits–a feasible but technologically (Homing Overlay Experiment) ABM intercep- difficult and costly Soviet countermeasure. An tor, which is currently allowed under the ABM additional disadvantage to this regime is that Treaty. Although such limitations would only attempts to define “new types” of ASATS be slightly more restrictive than those of the would be likely to result in the same ambiguity ABM Treaty, they would be very restrictive and distrust that resulted from attempts to when compared to a regime in which the ABM define “new types” of ICBMS in the SALT II Treaty was no longer in force. negotiations. Finally, the degree of protection afforded high-altitude satellites by a ban on testing “new types” would be uncertain; there 4. One Each/No New Types would remain some probability that an un- Regime four would include arms limitation tested advanced ASAT, if suddenly deployed provisions which would restrict the United and used, might actually work. Systems with States and the Soviet Union to their current inherent ASAT capabilities (ICBMS, ABMs, ASATS and prohibit the testing in an “A SAT maneuvering spacecraft) would also still exist. mode’ and deployment, in space, of more ad- As in the test ban and space-based weapon vanced systems. Existing treaties and agree- ban regime, a “no new types’ regime would ments would remain in force. In addition to limit the testing of some types of advanced banning the testing or deployment in space of BMD weapons which are currently allowed un- new types of ASATS, the “no new types” der the ABM Treaty. agreement would prohibit making current systems more capable so they could attack tar- 5. “Rules of the Road” for Space gets at higher altitudes. BMD systems would also be banned if they had ASAT capabilities. Whether or not the United States and the In a “no new types” regime, the passive Soviet Union agree to restrict ASAT weapons, countermeasures and nondestructive active they might negotiate a set of “rules of the road” for space operations. These rules could countermeasures that were discussed in the “existing regime” could still be developed and serve the general purpose of reducing suspi- employed. Destructive active countermeas- cion and encouraging the orderly use of space, or they could be designed specifically to aid ures such as “shoot-back” or DSATS could not in the defense of space assets. Examples of be tested or deployed but could be developed and held in readiness. Current ASATs—should general rules might include agreed limits on they already possess the capability when the minimum separation distance between satel- treaty is signed-could be used to attack other lites or restrictions on very low-altitude over- ASATS. flight by manned or unmanned spacecraft. These general rules might also be used to The primary advantage of a “no new types” establish new, stringent requirements for ad- regime, relative to the existing regime, would vance notice of launch activities. Specific rules be that, by prohibiting the testing of advanced for space defense might include agreed and A SAT weapons, highly valued U.S. satellites possibly defended “keep-out zones, ” grants or in higher orbits could be protected with some restrictions on the rights of inspection, and confidence. In addition, the United States limitations on high-velocity fly-bys or trailing could retain a capability to negate low-altitude of foreign satellites. It might also be desira- Soviet satellites (e.g., RORSAT) in the event ble to establish a means by which to obtain of war and to respond in kind to a Soviet timely information and consult concerning am- ASAT attack. biguous or threatening activities. 18

The “rules of the road” discussed above– There are too many satellites in low-Earth if implemented in the absence of restrictions orbit to accommodate large keep-out zones. on ASAT weapon development—would not re- However, it might be feasible to establish move the threat of ASAT attack. The primary smaller keep-out zones around such satellites purpose of such a regime would not be to re- and, in addition, to specify a minimum angu- strict substantially the activities of the par- lar separation between orbital planes to pre- ties, but rather, to make the intentions behind vent continuous trailing. these activities more transparent. Although the degree of protection for U.S. space assets 6. Space Sanctuary to be gained from a “rules of the road” agreement would be less than from other arms limi- Regime six would establish altitude limits tation regimes, the costs would also be cor- above which military satellites could operate respondingly less if other nations failed to but where the testing or deployment of weap- comply with such rules. One must assume that ons would be forbidden. A “space sanctuary” in the absence of ASAT arms control, both regime would not constrain ASAT weapon de- ASAT development and satellite survivabil- velopment, testing, or deployment in space ity programs will be given high priority. This but would attempt to enhance security by pro- being the case, offensive and defensive meas- hibiting these activities in deep space (i.e., ures would be available to respond to viola- above 3,000 nautical miles, or about 5,600 tions of “rules of the road. ” kilometers) where critical strategic satellites are based. At present, the altitude of these If they were defended, “keep-out zones” strategic satellites makes them invulnerable to would probably offer the closest thing to secu- attack by the current Soviet and U.S. ASATS. rity in a “rules of the road” regime. Space mines designed to shadow satellites and det- In a “space sanctuary” regime, the passive onate on command would lose a great deal of countermeasures and nondestructive active their utility if held at bay by a defended keep- countermeasures that were discussed in the out zone. Nonetheless, there are a number of “existing regime” could still be developed and difficulties with trying to implement this re- employed. Unlike the “test ban” or “no new gime, not the least of which would be the re- types” regime, destructive, active counter- action of other space-faring nations. measures such as DSATS could be tested and deployed, but not in deep space. Deployment ASAT weapons such as nuclear interceptors in deep space of ‘‘shoot-back’ capabilities or must be kept at a range of several hundred DSATS would probably be prohibited since it kilometers from moderately hardened satel- might be impossible to differentiate these lites in order to protect such satellites; ad- weapons from offensive ASATS. vanced directed-energy ASAT weapons might have to be kept much farther away. Given the The primary advantage of this regime would number of satellites currently in orbit, this be that it could protect satellites in high or- would present several problems. Satellites in bits from the current generation of ASAT geostationary orbit are already so closely weapons. In addition, a deep-space sanctuary spaced that a keep-out zone sufficiently large regime would constrain ASAT development to protect satellites from a nuclear weapon less than would a comprehensive test ban re- would displace other satellites. It is possible gime or a no-new-types regime. However, that critical strategic warning and communi- should the United States and the Soviet Un- cations satellites could function in supersyn- ion choose to pursue advanced ASAT weap- chronous orbits.8 If so, there would be ade- ons, a space sanctuary might offer only limited quate room to accommodate large keep-out protection. zones around satellites in such orbits. The greatest risks in a space sanctuary regime would be posed by advanced directed- ‘I.e. higher than geosynchronous orbital altitude. energy weapons which could be tested and de- . 19 ployed at low altitudes. Such testing and deployment would probably be adequate to guar- 7. Space-Based BMD antee effectiveness against targets at higher The seventh regime might result from U.S. altitudes. Satellites at very high, supersyn- or Soviet withdrawal fro-m the ABM Treaty chronous altitudes might still derive some pro- followed by the deployment of space-based tection from this regime, but violation of the BMD systems. Since even a modest BMD sys- sanctuary by highly maneuverable kinetic- tem would make a very capable A SAT weap- energy weapons or by satellites covertly car- on, in a “space-based BMD” regime there rying powerful nuclear or directed-energy could be no attempt to restrain ASAT devel- weapons would remain a risk. For this reason, opment. Moreover, each side would probably sanctuaries might provide less security than want the freedom to develop new A SAT weap- would keep-out zones (discussed above), be- ons capable of destroying the opponent’s cause any foreign satellite entering an agreed space-based BMD systems. keep-out zone could be fired upon, while a satellite entering a sanctuary could be lawfully The ASAT weapons allowable under the fired upon only if it could be proven that it “spacebased BMD” regime would include all was, or carried, a weapon. of those in the “existing regime, plus weap-

Artist’s conception of the Space Shuttle deploying a neutral particle beam weapon.

Neither of the weapons I Illustrated here exwts today, but I n the absence of agreed limitations, both the United States and the Soviet Union WI I I probably develop a wide range of advanced space weapons. 20 ons capable of countering ballistic missiles in ASAT countermeasures must prove to be ef- flight. Defensive measures would be less con- fective for spacebased BMD platforms if a de- strained and more essential than in the “ex- cision to deploy them is to make sense. Per- isting regime. In particular, advanced space- haps large improvements in the effectiveness based weapons such as neutral particle beam or economy of passive countermeasures such weapons could be deployed at low altitudes as combinations of hardening, deception, and and then used as ASAT or DSAT weapons. proliferation would provide the needed protec- Passive countermeasures and nondestructive tion. Alternatively, the superior fire-power or active countermeasures like those discussed massive shielding of BMD weapons might in the “existing regime” would be developed give them a degree of protection unattainable and employed. by smaller, less capable satellites. Depending on one’s viewpoint, the principal With respect to other military satellites, the advantage, or disadvantage, of a space-based expense of equipping them with countermeas- BMD regime would be that it would allow the ures to insure some level of survivability United States and the Soviet Union to deploy against advanced BMD systems would be con- highly capable weapons in space. On March siderable. However if, as some argue, space- 23, 1983, President Reagan called for a vigor- based missile defenses could make us more se- ous research program to determine the feasi- cure and encourage the Soviets to make real bility of advanced BMD systems, suggesting reductions in offensive missiles, this would re- that the deployment of such systems, if fea- duce the threat of U.S./Soviet conflict. In a sible, could offer an alternative to the current world where conflict was less likely, satellite stalemate in strategic nuclear weapons. Given vulnerability would be less important. the inherent ASAT capabilities of advanced Others, of course, disagree strongly with BMD weapons, satellites would be most vul- this argument. They claim that space-based nerable in a space-based BMD regime. Before missile defenses will decrease our security by the United States deployed space-based BMD systems it would have to determine, first, that encouraging greater competition in both offensive and defensive weapons. In a world of the contribution that such systems made to space-based weapons and higher U.S./Soviet U.S. security was great enough to compensate tension, satellite vulnerability would be a crit- for the threat which similar opposing systems ical and potentially destabilizing factor. would pose to U.S. satellites; and, second, that space-based BMD components could be protected at competitive cost against advanced ASAT weapons.

TREATIES OF LIMITED DURATION Each of the regimes examined above could tions for the indefinite future.g Treaties of be negotiated as a treaty of indefinite or limited duration allow parties to take advan- limited duration or, alternatively, as one which tage of future technological options, yet can remained in force as long as periodic reviews were favorable. Each of these alternatives Wheaties of unlimited duration usually contain a clause which would have its advantages and disadvantages. states that if a country’s “supreme national interests” are threatened, then that country may withdraw from the treaty, Treaties of indefinite duration are more effec- In addition to “supreme national interest clauses, ” treaties may tive at discouraging the pursuit of banned also contain specific unilateral or agreed statements regarding activities, yet require a greater degree of fore- specific understandings about related events. For example, The 1972 ABM Treaty contains a unilateral statement by the LJnited sight regarding the long-term interests of the States which links the continued viability of the treaty to “more signatories and can foreclose technological op- complete limitations on strategic arms. ” 21 encourage aggressive development programs tinued in force after they had expired (e.g., the designed to reach fruition at the termination “Interim Offensive Agreement” signed at of the designated period. Treaties which call SALT I). The real issue would be whether the for a periodic reassessment of agreed limita- parties believe that adherence to the treaty in tions in theory have great flexibility, yet, in question continued to be in their national secu- practice, often result in a strong presumption rity interest. that they should be continued. The Reagan Administration has recently in- The United States might, for example, en- dicated that it intends to conduct ASAT tests ter into a treaty limiting ASATS with the ex- to gather information useful in advanced plicit and public reservation that we would BMD research.l” Given the close connection withdraw from this treaty if and when we were between these two technologies, an ASAT ready to test and deploy a ballistic missile de- treaty of even limited duration would require fense system in ways that the ASAT Treaty modification of current SD I program plans. would forbid. Alternatively, we might take the Thus, to the extent that the United States public position that we intended to restrict our wished to maintain the most rapid pace of ad- BMD activities so as to remain within the vanced BMD research within the bounds of limits of an ASAT Treaty. While the former the ABM Treaty, such a treaty would not be position would suggest a treaty of limited du- desirable. Conversely, to the extent that the ration and the latter a treaty of unlimited du- United States wished to slow the pace of So- ration, this need not be the case. It would be viet BMD research and would be willing to de perfectly possible to sign a treaty of unlimited fer decisions regarding the testing of space- duration, with the standard provision allow- based or space-directed weapons, an ASAT ing for withdrawal, accompanied by a clear treaty of limited duration could contribute to statement of some of the conditions under that result. which we intended to withdraw.

- From one point of view, the exact language jOThe ~urpo9e of ~9t9 ‘ ‘in an ASAT mode’ would be to in in a treaty regarding its duration would be less vestigate advanced technologies without violating the ABM Treaty. The Department of Defense recently told Congress that, important than the intentions of the parties. “To ensure compliance with the ABM Treaty the performance After all, there have been numerous examples of the demonstration hardware will be limited to the satellite of treaties of unlimited duration that were vio- defense mission. Intercepts of certain orbital targets simulat- ing anti-satellite weapons can cleady be compatible with this lated soon after they were signed and exam- criteria. ” [Report to the Congress on the Strate@”c Defense Im”- ples of treaties of limited duration that con- tiative, Department of Defense, 1985, app. B, p. 8.]