American and Soviet space planners are both familiar with the concept of "windows"-transient time periods when the positions and relative movements of the earth and the target planet or planets are such that a probe vehicle launched during the window can reach the target. In effect, the window exists when a number of variable factors, some independent, some interacting, are in phase at the same time.

A similar concept applies to arms control negotiations. Great strides are possible only under "window" conditions, when the negotiating parties are simultaneously driven to seek agreement by their interacting positions. The variables that determine those positions are many: strategic concepts, the state of technological development, weapons inventories and ongoing programs, control and verification capacities, and, most fundamentally, budgetary and political forces. All of these must be at least in a neutral position, and some must be pressing, if the resistance of inertia, hostility, suspicion, special interests and the momentum of weapons programs is to be overcome.

The classic case of an open window perceived and acted upon was the Anti-Ballistic Missile Treaty that was the centerpiece and major accomplishment of the SALT I agreements of 1972. That treaty essentially eliminated ABMs as an element in the strategic balance. It ended, for practical purposes, both the U.S. Safeguard and Soviet Galosh programs then in progress, programs which, in the judgment of all but a handful of strategic thinkers, could only have been destabilizing. And it saved both countries from very large expenditures.

On the other hand, the SALT II negotiations that ran from 1972 to the final set of agreements reached in 1979 suffered for lack of the window conditions, chiefly the obstacle of ongoing weapons programs of great momentum. Given a ratified SALT II treaty, however, a spectrum of factors will come together in the next negotiating period to open a window for arms control on a major scale, especially with respect to reducing or eliminating the deployment, on land-based ICBMs (intercontinental ballistic missiles), of multiple independently targetable reentry vehicles (MIRVs). A similar window may be opening with respect to theater nuclear weapons in the NATO area, although it will be more difficult to deal with. But if the problem of MIRVed ICBMs can be tackled successfully, the way may be open for a truly productive SALT III.

II

To understand how the SALT III window may work, it is worth noting briefly the conditions that made the ABM agreement possible:

1. Strategic concept. On the U.S. side in particular, there was grave concern that ABMs were inherently destabilizing. To the extent that they even appeared to offer protection to strategic targets, they made the requirements for attacking forces volatile and unpredictable, a clear field for worst-case planners. They were bound to stimulate increases in offensive weapons on both sides, and in programs for evading or overcoming defenses.

2. Technological status. The U.S. ABM system was under severe attack; experts contended that it was of fundamentally defective design for its stated objective, the defense of the intercontinental ballistic missile (ICBM) fields. The U.S.S.R. program was proceeding very slowly if at all, suggesting that it, too, was being basically reexamined. Both sides had gone far enough to realize that while ABM systems could be created, they would be of doubtful effectiveness.

3. Weapons balance. The Galosh system was ahead of Safeguard, with some ABMs actually deployed. Safeguard, however, was technically more advanced and proceeding more rapidly. Neither side had a successful program clearly in prospect. On the contrary, emphasis on ABM, by either side, could only stimulate the other's programs both in ABM and offensive weapons.

4. Expense. The costs of the ABM development itself would be substantial for both sides, and the additional expense of the programs stimulated by the ABM could be foreseen.

5. Control and verification. Finally, there was available a realistic set of arms control proposals, including adequate verification.

Just how these factors translated into political pressures on each side must be a matter of judgment. In hindsight, the Soviet leaders may have been less influenced by the strategic argument (which had been pressed on them as far back as the Glassboro summit of 1967) than by their limited technological possibilities, the relatively higher momentum of the U.S. program, and the expense. On the U.S. side, regional domestic opposition to any widespread U.S. deployment, and a powerful opposing campaign by technical and academic experts combined with public supporters of arms control were special added factors. What is clear is that both sides came into focus at roughly the same time, with similar basic calculations.

As a contrary example, in the same SALT I negotiations of 1969-72, no agreement or even serious negotiation was possible concerning MIRVs. Highly successful U.S. MIRV programs were in full swing, starting their deployment to operational forces, while the U.S.S.R. was in an early development phase. With such an imbalance, the United States could not generate a control proposal, carrying anything approaching an Administration consensus, which did not maintain a U.S. advantage. The Soviets, whose ability to catch up in a few years was easily predictable, and freely predicted, were disinclined to limit MIRVs until they had caught up, and in any case were completely and understandably unwilling to agree to a permanent MIRV inferiority. In brief: no window-no agreement.

Similarly, the development of these weapons systems and extensions thereof have obstructed breakthroughs in the SALT II negotiations. The Soviet programs, leading to their fourth-generation systems (SS-17, -18, and -19), are not only catching up in qualitative terms-MIRVs and improved accuracy-but are continuing to expand the U.S.S.R.'s ICBM force. In effect, they have been adding improved quality to increased quantity in a way which the United States was bound in the end to respond to with a new missile program of its own. At the same time, the United States has been completing its initial MIRVing program, improving accuracies and yields, starting new submarine and submarine missile programs, and-to a degree perhaps more disturbing to Soviet leaders than we had thought-moving well ahead in the development of high-accuracy cruise missiles of long and intermediate range. In these circumstances, it is understandable that SALT II accomplished less substantive arms control than was hoped, and the very real accomplishments of SALT II are all the more remarkable.

For SALT III, however, both technological and cost advantages in far-reaching arms control measures should exert essentially equal magnetism for both sides. New technology, especially high-accuracy, mobile ICBMs and IR/MRBMs (intermediate- and medium-range ballistic missiles), as well as cruise missiles, confronts the two superpowers and their allies with new or intensified threats. Turning these potential threats into actual hardware, and developing and producing the weapons to counter them, will call for large new or expanded weapons programs on both sides. These programs will be destabilizing. They will be immensely expensive. They will, in some cases, be technically very difficult and uncertain, as, for example, the method of basing the proposed U.S. mobile ICBM designated MX. They will in some cases be politically very complex and divisive, e.g., the establishment, control and location of a cruise missile force, or an IR/MRBM force, in Europe. And, as always, the counter-programs will themselves be subject to countering in due course.

At the very best, all these programs can promise is a renewed temporary standoff, at an even higher level of weaponry, after a dangerous, unstable and very expensive buildup.

On the other hand, there is, in the same time frame, a basis for arms control agreements which could control the new threats without tilting the U.S.-Soviet (or NATO-Warsaw Pact) strategic balance. This is the window.

At present, and for a substantial period ahead, only ICBMs with MIRVs pose a preemptive counterforce threat to land-based ICBMs that could destabilize the nuclear balance. ICBMs with single warheads, however powerful, can destroy on the average only some fraction less than one silo each; the attacker in a silo-to-silo duel expends more weapons than he destroys and gains no advantage; the value of striking first evaporates. Submarine weapons lack the combination of yield and accuracy to threaten a major ICBM system in hardened silos, and the problem of controlling the immensely complex and time-sensitive counter-force attack would be formidable from submarines. Bombers, with or without cruise missiles, lack the necessary speed; warning time would be measured in hours, much too slow for preemption. It is only MIRVed ICBMs, and, indeed, only advanced MIRVed ICBMs such as fourth-generation Soviet weapons and U.S. MX and Minuteman III with Mark 12A warheads, that have the requisite combination of warhead numbers, yield, accuracy, speed, reliability, and tight controllability to attack entire ICBM systems. In brief, were the MIRVs on ICBMs eliminated, fixed ICBM vulnerability would go with them. Thus we should work in SALT III to eliminate MIRVed ICBMs.

Granted, this would not be a permanent fix. But it should last for a substantial weapons generation or more, until, say, submarine-launched ballistic missile (SLBM) accuracy, yield and control were markedly enhanced. And that problem could be handled by qualitative controls in future SALTs before it became acute.

III

Ratified SALT II agreements will make an important, probably essential, contribution. The accompanying "Statement of Principles" prescribes early resumption of SALT negotiations aimed specifically at reducing numbers, controlling weapon developments, and ensuring verification; the stage will be set for progress.1 SALT II's provisions for equal numbers of strategic launchers provide the necessary common base for reductions and establish the principle of equality. SALT II's verification provisions are of central importance: MIRV counting rules, prescribed data exchanges, advance notification of certain tests, as well as the provisions, carried over from SALT I and further clarified in SALT II negotiations, against interference with or concealment from national technical means of verification (i.e., technical intelligence-gathering systems), are not only necessary in themselves, but are essential precedents for the intrusive, probably cooperative, verification measures that will be needed in later agreements. The limits set in SALT II on the number of warheads per missile reduce the worst-case projection of the total numbers of warheads the Soviets could load on their ICBMs, which are larger and of greater carrying capacity ("throw-weight") than ours; these limits are also a precedent for further warhead controls and reductions. The program restraints contained in the SALT II Protocol, especially those on deployment of ground- and sea-based cruise missiles and mobile ICBMs, while they do not restrain development and thus do not interfere with the negotiating leverage of these systems, emphasize their importance and focus ongoing negotiation on them.

SALT II has another major value, perhaps inadequately appreciated. It cleans out a mass of underbrush that stood in the way of progress, laying down precise agreements, understandings and treaty terms on a long list of disputable points (the distinction between a modernized and a new missile, the counting of aircraft with cruise missiles, the definition of throw-weight, the dates when weapons pass into and out of the countable inventory, and dozens of other specifics). Given a ratified SALT II, none of this laborious effort need be repeated; much of the future work, indeed, could be accomplished merely by additions to, or revisions of, articles of SALT II. Also, the long negotiations have improved communication and understanding on both sides, at many levels of government and throughout growing arms control communities; there is a much clearer and readier perception of what the situation is and what the problems are. This will expedite and focus future negotiations.

Rejection of SALT II by the Senate, whether outright or by "killer amendments," would abruptly stop the SALT process, and surely have a negative impact on other arms control negotiations. How long it would take to regain momentum, if it could be done at all, and how much damage would have been done to the terms already agreed to and to the authority any Administration would bring to further negotiations, can perhaps be debated. Clearly, however, there would at best be much to do again, by negotiators commanding less confidence, in an atmosphere exacerbated by rejection of a hard-fought compromise.

By about the terminal date of the SALT II treaty, in 1985, if negotiations have not been successful, the new weapons, even those not yet deployed, will be accepted elements of the new strategic balance. Great investments will have been made; the programs will have widespread support and immense momentum. Defense planners will be concentrating on the next weapons generation-on the counters to the counters. Somewhere in that time frame, the current opportunity will slip away; this particular window will close. But with SALT II, there is an opportunity of unprecedented scope.

IV

As we have noted, the United States faces a situation in which its Minuteman system will, in the mid-1980s, be theoretically vulnerable to a preemptive strike by a fraction of the Soviet fourth-generation ICBMs (SS-17, -18, and -19), assuming the accuracies, yields and reliabilities now estimated for these weapons and the SALT II constraints on their missile and warhead numbers.

Such an attack would leave untouched the ample retaliatory capabilities of our at-sea submarines and alert aircraft. Further, the outcome of the attack is highly questionable, considering the great uncertainties confronting the attacker. The attacker's forces would be entirely inexperienced in large-scale launchings, and this would be an attack of great complexity in targeting and timing. The chances of serious mistakes would be substantial, and he would have no valid estimate of his "operational degradation," i.e., the reduction in accuracy, reliability and timing between single test firings on target ranges and mass firings from regular silos with ordinary crews under extreme tension. He cannot know with precision the resistance of our silos, nor, given the limits of geodetic precision, their exact position in relation to his launch points. In a mass attack, he, like us, has no experience of the effects of the detonations of leading weapons on following ones (fratricide), nor of the dust the leading weapons throw up, and if he designs his attack to separate the detonations in time and space to avoid fratricide and dust, the attack will take considerable time-hours-to complete, during which many yet unhit Minutemen could be fired in retaliation. He cannot be sure of the weather in the widespread target areas, which can have measurable effects on the arriving weapons.

Finally, the U.S. response to such a counterforce attack would be unpredictable, even by ourselves. The attacker could not be sure that the United States would not "launch on warning," that is, fire its ICBMs when the incoming strike was detected, before it hit, leaving only empty silos to receive the attack. And he surely could not count, with any confidence, on our government making a cool, analytical weighing of forces in such a situation, under appalling pressures, with the immediate dead-even in an anti-silo attack-counted in the millions. He would have to reckon with the substantial probability that the response would be a general strike by our immense remaining forces against his cities and population, essentially destroying the fabric of his country, even in the face of his capacity to do the same to us.

The expected vulnerability of Minuteman, when and if the Soviets achieve their anticipated accuracies in the next few years, is therefore of limited significance in a direct operational sense. Nevertheless that vulnerability, however theoretical, can be felt by us and seen by others as a U.S. weakness; in times of tension it could expose us or our allies to political pressure from nuclear threat. Perhaps more important, vulnerable Minutemen could be a destabilizing factor in a time of high crisis. The Soviet ability to destroy a high percentage of our ICBMs would put a premium on our striking first; in a situation where a strategic exchange seemed more and more probable, to the point of inevitability, some relative advantage from the first strike could be the final persuading factor. Finally, strikes against vulnerable ICBMs are at the heart of strategic concepts aimed at "limited" nuclear warfare at the strategic level. The ICBMs provide a "legitimate" (i.e., not urban-industrial or population) target system of significant value. Such concepts, giving apparent rationality and purpose to the actual use of nuclear weapons, erode the barrier between nuclear and non-nuclear warfare. They reduce nuclear deterrence.

Such considerations have brought the Administration to the decision to proceed with the development of a new mobile missile, the MX, and to pursue as a priority the question of its mobile basing. Senate SALT II hearings likewise leave no doubt that the Congress, too, is determined to proceed with necessary equalizing programs.

As in the ABM treaty case, it is not possible to be sure that these concerns, in the areas of strategic concept, deterrence, instability, and computer-calculated outcomes of nuclear exchanges, are felt as strongly on the Soviet side as they are in the United States. One simply cannot know whether the Soviet civilian leadership believes what some Soviet military theoreticians write about being prepared to fight nuclear war at all levels. But the Soviets are clearly capable of understanding and absorbing the U.S. determination to equalize, and the capacities of our proposed programs. They will feel that weight increasingly as the programs progress. It cannot fail to be clear to them, as to us, that the prospect is for an extremely expensive and, in the end, fruitless further competition unless an arms control avenue is found.

The MX is designed to be larger than Minuteman, to carry ten warheads (in place of the three in Minuteman III) of substantially higher yield and remarkable accuracy. It is to be carried in a mobile launcher and based in some sort of protective concealment system (trenches, multiple silos, "race tracks," conceivably in alert aircraft or waterborne in vehicles other than ocean-going submarines or bottom crawlers). It is expected to have limited vulnerability to attack-the land systems would be unprofitable counter-force targets because they would require greater expenditures of attacking forces than would be offset by losses of MX; the air and sea basings would themselves be protected by their mobility while in the air or at sea. The ten-year costs of a 200-missile system are currently estimated at $30 billion; experience suggests that estimates of weapons system costs made at this early stage are almost invariably markedly low. The present schedule calls for the system becoming operational commencing in 1986 and being completed in 1989; production delays, like cost overruns, are not unheard of in weapons procurement.

The MX system, then, when and if it meets its design goals, will overcome the present threat to Minuteman. In addition, the system will have sufficient capability to threaten the U.S.S.R.'s ICBMs as they now threaten ours. Subject to the same reservations that were outlined above about the significance, in operations, of Minuteman vulnerability, the MX system, once operational, would be theoretically able to destroy a very high percentage of Soviet ICBMs in their silos. Indeed, the threat to the Soviets would be greater than theirs to us, in that a higher proportion of their strategic power is concentrated in ICBMs-some 70 percent of their strategic warheads and over 80 percent of their strategic megatonnage, whereas for the United States the figures are about a quarter of the warheads and 40 percent of the yield.

Even the Soviet residual force, after discounting its ICBMs, would be a formidable, probably ample, deterrent. Still, the perceived threat would exist, as the threat to Minuteman does for us. Almost certainly the Russians would have to follow us into some form of mobility or concealment. At a minimum, this would require a major, entirely new, mobile weapons system. If their decision were to replace the capabilities of their entire fourth-generation fixed ICBM system, the new system would have to carry some three times the warheads of the proposed MX system-a massive program.

The product of this cycle, after a decade or more of dynamic instability as one and then another program reached operational status-and as possible weaknesses or vulnerabilities of the new systems were exposed and exploited or corrected-and after vast expenditures on both sides, would be at best two new opposed ICBM systems, neither vulnerable, for a time, to the other's preemption.

But this would be by no means the end of the matter. The Soviet fourth generation will threaten the Minuteman; the MX will threaten the fourth generation; new developments, in turn, will threaten MX. Nuclear arms expert Richard Garwin has already suggested to the House Armed Services Committee (February 7, 1979) that quite feasible "pin-down" tactics-detonating a series of weapons in the airspace above the MX deployment areas-could deny the use of land-based MX, for periods of hours, at times of the Soviet's choosing. (The same possibility exists for U.S. and Soviet ICBM fields, and for any future Soviet land-based mobile ICBM deployment area.) Speaking of the multiple aim point (MAP) basing system, a kind of massive "shell game" then apparently the leading candidate for MX basing, Garwin also pointed out that if adopted by the U.S.S.R., it would raise the specter of a Soviet "break-out" from SALT.

The thought here is that (1) SALT permits building and storing, but not deploying, additional missiles, and (2) allows for denunciation of the treaty by either party on six months' notice under the supreme national interest clause, while (3) MAP would require building a large number of protective silos. If either country built the weapons and silos-a thousand or more-and then denounced the treaty, a substantial ICBM reinforcement would require only the building of the launchers to hold the missiles in the silos, and the six-month denunciation notice-a relatively brief period. (A similar possibility exists in other land-based systems where a large number of protected launch points is built for a small number of ICBMs.) Garwin thinks that five years after this country went ahead with MX in MAP, there would be "as much concern and search for an alternative to MAP, in view of its potential vulnerability, as there is now a sense of urgency to do something about Minuteman." Problems of this nature apply to all the so-far suggested basing systems, for the United States and U.S.S.R. alike.

In short, the weapons-building route, the arms race, is inescapably unstable and unreliable. Clearly, if the end can be met by an arms control agreement, that would be the less dangerous, the less expensive, and the less hostile path.

V

Eliminating MIRVed ICBMs should not be beyond the limits of negotiability. It could be adequately verified by national technical means, supplemented by a ban on any further testing of ICBMs with MIRVs. It would require the United States to convert its 550 Minuteman III missiles to single warheads. The U.S.S.R. now has something over 600 MIRVed ICBMs, presumably building toward the SALT II limit of 820; that would have to be converted. Both sides possess tested single warheads for the ICBMs involved.

The U.S.S.R. would reduce its warheads by a greater number-on the order of 5,000 (assuming the full 820 Soviet MIRVed ICBMs) to the U.S. 1,100. Numerically, then, the Soviet reductions would be the greater.

Timing (the period of the open window) is, as always, an essential consideration. There is a range of key dates. The SALT II Protocol will expire at the end of 1981, ending the ban on deploying mobile ICBMs (including the U.S. MX). Soviet fourth-generation ICBMs, with high kill probabilities against Minuteman silos, are expected to be essentially deployed in the early 1980s, as are U.S. aircraft armed with air-launched cruise missiles (ALCM). SALT II expires at the end of 1985. The MX missile is scheduled for deployment during the late 1980s.

What these dates indicate is that the Soviet weapons which bring ICBM vulnerability to a head will be in place a few years ahead of the proposed U.S. counters. Further, the U.S.S.R. may share our view that multiple warheads are the major benefit of their larger ICBM throw-weight, and feel that a MIRV ban would surrender a significant Soviet advantage. They may value the transient superiority in ICBM counterforce capability that will exist from completion of the fourth-generation deployments in the early 1980s until MX is operational. They may be-probably will be-disinclined to trade hardware going into deployment, the fourth generation, against weapons under development, the MX. It is a truism that neither nation is normally willing to bargain an actual against a hypothetical system.

However, there are countervailing considerations. The countering weapons are clearly within our capacity to develop and produce; the recent presidential decision on MX and the Senate SALT II debates have made clear that we are determined to produce them. Congressional action on the defense budget will drive the point home. Thereafter, MX forward movement will be clearly evident, month by month. The technology of the missile is in hand; the basing is complex theoretically but its construction is straightforward. The Soviets will be able to observe its momentum, and they are aware that weapons programs tend to become irreversible. In brief, MX probably has some leverage with the U.S.S.R. now, and it will steadily gather leverage during the SALT III negotiating period. This process will be stimulated by the quicker and more precise dialogue on strategic nuclear matters, between the superpowers, that the past ten years of the SALT process have created.

Further, the Minuteman III, when upgraded with the Mark 12A warhead and the NS-20 guidance system, will itself have substantial hard-target kill potential. Were the United States to upgrade all 550 Minuteman IIIs (1,650 warheads), they could fire two warheads at each of the 820 Soviet MIRVed ICBMs and theoretically destroy some 75 percent of them (more with the introduction of marginal improvements expected in the next two or three years). It would clearly be worthwhile from the Soviet standpoint to eliminate this U.S. capability.

The Soviets have seen, in the case of MIRV-as we have-that advantages are temporary. We can hope they will be more ready to look ahead. And the possible agreements are of great value to both sides. In brief, the window is already cracked, and will open progressively wider through, say, the first half of the 1980s.

Against the point that greater Soviet ICBM throw-weight may make ICBM MIRVs more valuable to them, one can balance the facts that, first, they have already accepted, in SALT II, restrictions on numbers of warheads per missile-they are not, apparently, concerned to get maximum fractionalization. Second, since single warheads have greater yield than the aggregate of MIRVs on the same missile, the Soviets would gain in megatonnage; in the past, they have developed and tested very high-yield war-heads-they may well find value in the megatonnage gain.

As far as the Soviet mid-1980s ICBM counterforce superiority is concerned, the rebuttal is self-evident. First, it is operationally unusable. Second, it is destabilizing and dangerous. Third, it could not be decisive; our retaliatory capacity is ample, redundant, and (with air-launched cruise missiles) growing, even assuming an unrealistically successful Soviet preemptive strike. Fourth, it is transient. MX, once deployed, will not merely cancel the advantage, but reverse it.

Those are, so to speak, the mechanics. More fundamentally, both sides would benefit from the agreement. From the U.S. standpoint, we would regain confidence in our Minuteman system. There would no longer be great concern about preemptive counterforce attacks against them, nor about the destabilizing effects of their theoretical vulnerability; "limited" silo-to-silo exchanges would lose such rationale as they now have. This country would sense improved deterrence, improved stability, and strengthened validity of our basic "assured second strike" strategic concept.

On the Soviet side, similar advantages accrue. They may not evaluate them as we do, of course, but even if they do not share our strategic concepts, the practical situation they confront will be quite clear, and they are at their best in evaluating the "objective factors." Their mid-1980s advantage is limited, not decisive. The oncoming MX program will reverse the advantage, put at risk their entire ICBM system, and require an equivalent system of their own. In a sense, therefore, rather than trading hardware against concepts, the Soviets could view the ICBM MIRV ban as trading away a moving MX program against the hypothetical Russian system MX would almost certainly require them to build. It is a good deal for the Soviets too.

Both parties would waste enormous amounts of money and resources on a mobile ICBM race. The Soviet cost would depend on the scale of their program, but it is unlikely to be less than the low estimate of $30 billion cited for the United States. If they made a complete changeover to mobile systems at their current force levels, it could be two or more times greater. Both would be faced with technical and strategic uncertainties; the mobile-basing problem is not solved, and mobility will at once raise the question of counters, and counters to the counters. Both would lose in intelligence confidence and SALT verification; verification of mobile systems is intrinsically less certain. And both parties-and their allies-would confront a decade or more of increased hostility and lessened stability from an intensified and dynamic arms competition.

The agreement, overall, would be balanced and equitable, causing no long-term tilt in the strategic relationship. Both sides would retain ample, indeed excessive, deterrent and retaliatory capacity. The Soviets would retain their lead in total yield and in missile throw-weight, but the significance of throw-weight would be markedly lessened when it could no longer be converted into a multiplicity of warheads. The Soviet advantages would be balanced by the U.S. lead in numbers of SLBM warheads and in bomber capabilities.

The elimination of MIRVs on ICBMs is not the only arms control route to reducing ICBM vulnerability. President Carter's "comprehensive proposal," at the start of his term, sought the objective largely through reductions in Soviet throw-weight, combined with control of increasing accuracy by limitations on missile testing. As formulated, the proposal was arguably inequitable, but, more important, the SALT II foundation had not been laid and the MX counterthreat was unborn; the window was not yet open. Others have proposed moving to, or at least toward, a dyad; eliminating the vulnerable ICBM system, or reducing it to minor proportions, and relying on air- and submarine-carried weapons for strategic deterrence. This would make our ICBM force into a bargaining chip in pressing for deep Soviet reductions in forthcoming negotiations.

McGeorge Bundy, in a thoughtful article in International Security, proposes that the triad be maintained, but not with MX. He would replace the Minuteman with a new system to serve as the triad's third leg: a mobile system embodying MX's reduced vulnerability,2 but deliberately designed not to have the accuracy/yield/numbers characteristics which would threaten the Soviet ICBM system. It would thus cure the problem of Minuteman vulnerability, without driving the U.S.S.R. to a massive change-over to a mobile system. Verifying its limitations might be tricky. Even so, willingness to shift from MX to a Bundy-type system would be a powerful bargaining chip in arms control negotiation.

No such ideas should be dismissed. They should be explored in depth in preparing for SALT III negotiations. In the absence of new insights, however, eliminating ICBM MIRVs appears to be the most direct and effective cure for the problem of Minuteman vulnerability.

VI

In addition, an ICBM MIRV ban would be notably fruitful in opening up other aspects of SALT III. It should make both sides willing to agree to a complete ban on mobile ICBMs, since the key motivation for such systems would be removed. This would not only halt a major step-up in the arms race, but would make a valuable contribution to verification. As we have noted, verification of mobile weapons is intrinsically more difficult, and it will be hard indeed to make MX reliably verifiable without reducing the invulnerability of the system. The solution chosen may be subject to Soviet challenge as a violation of SALT's verification provisions. Further, we might-and probably would-be dissatisfied with the Soviet solution to the same problem in their answering system. The result could be a serious setback to verification generally and to strategic weapons control.

Also, an ICBM MIRV ban should lead to an agreement to flight test or deploy no new types of ICBMs, rather than the one new type apiece allowed in SALT II. Our SALT II motivation for insisting on one new type was to permit MX, or its equivalent; the Soviet purpose is not surely known-perhaps they felt a need for a single warhead replacement for the SS-11. In any case, the ICBM MIRV ban should remove the requirement for both parties. This would still permit both sides to "modernize" their systems within the SALT II rules (perhaps refined in SALT III). Such modernization permits considerable development, but the agreed limits would prevent sharp, destabilizing changes.

Once the Minuteman vulnerability problem is in hand, SALT III should be capable of truly substantive strides. For openers, both sides could presumably agree on banning air-to-surface missiles. More broadly, both sides have agreed on "significant and substantial reductions of strategic offensive arms" as a SALT III objective. The basic SALT II aggregate number (2,250 ICBM and SLBM launchers, plus strategic bombers) could be cut by a flat amount-1,800 has been suggested for the initial step, with further steps to be negotiated later-or the parties could adopt the proposal advocated by a number of experts: cutting the total by a fixed annual percentage, say five percent, either for a stated term of years or indefinitely, until one or the other party calls for renegotiation. In either case the reductions would be meaningful.

The internal sublimits would come down sharply. The 820 limit on MIRVed ICBMs would of course go to zero, and consequently open the 1,200 limit (ICBM plus SLBM) and 1,320 limit (ICBM plus SLBM plus bombers with ALCM) to steep reductions. The end figure will require hard negotiation. The United States relies on these relatively stabilizing air- and submarine-launched weapons for two legs of its deterrent triad, and on their large numbers of warheads to balance the Soviet margin in ICBM throw-weight and megatonnage. The Soviets might argue for smaller figures than we can agree on, though they, too, have a large investment in submarines. In any case, both sides should be ready for tightening of limits in the ALCM/SLBM areas.

The cruise missile question will be ticklish. The United States has settled on ALCMs, in preference to the B-1 penetrating bomber, as its chief aircraft-carried retaliatory weapon, and ground- and sea-launched cruise missiles are under consideration for NATO support (as is discussed more fully in the next section). The U.S.S.R. is understandably concerned about both. The United States will be unwilling to accept deep numerical cuts or seriously constraining qualitative limits on air-launched cruise missiles, and will be unable to discuss ground-launched or ship-launched cruise missiles substantively until the European theater question has been considerably discussed, and then only in concert with its allies.

So there will be hard bargaining on several issues. But the result should be a SALT III that would be truly stabilizing.

VII

One other destabilizing situation today is the increasingly perceived nuclear threat to NATO Europe. Soviet development of the SS-20 mobile IRBM, the Backfire bomber, and the SS-21 tactical missile appears to be creating the possibility of a counterforce type of attack that would make NATO's own nuclear capabilities highly vulnerable. A NATO response to these concerns is almost inevitable and perhaps approaching decision. Do we, then, have a parallel to the problem of ICBM vulnerability, with the elements of concern, threat, and potential counter-threat all present? I believe we do, and that the result could be another important window for arms control.

Europe has been vulnerable to nuclear destruction for nearly 20 years. It is not now possible to eliminate that threat to NATO Europe or to the Warsaw Pact countries, any more than to the United States or the U.S.S.R. Were there nothing else, were there no tactical or theater nuclear forces, each alliance is targetable by the opposing superpower's strategic forces, each armed with ample excess destructive capacity.

The significance of the new theater weapons is not that they alter that overall vulnerability, but that they can be perceived as reducing an element of theater-level deterrence by increasing the Soviet capacity for counterforce attacks. NATO Europe has relied for nuclear deterrence, and, if necessary, nuclear support, primarily on U.S. strategic forces, supplemented by U.S. nuclear elements based in Europe, allied "two-key" forces, and French and British national forces. These forces have not been invulnerable to attack-by aircraft, by overrunning, by strategic or other weapons-but the new Soviet weapons, especially the mobile SS-20 with its multiple warheads and high accuracy, have greatly increased ability to attack NATO nuclear elements, and other military targets, with high kill probabilities and little warning.

The increased threat to theater forces combines with European concerns about the certainty of the "coupling" of external U.S. strategic forces, the primary deterrent. Europeans, that is, cannot be absolutely sure that our strategic forces would if needed be committed to hostilities confined to the European theater-NATO treaty or no NATO treaty-now that such commitment would most probably result in the destruction of the United States. Europeans therefore understandably give some attention to the contingency of a theater nuclear war confined to Europe; in this scenario, increased Soviet counterforce capacity is significant.

Accordingly, several allied programs have been conceived to counter these Soviet developments. They include deploying extended-range Pershing missiles and additional modern nuclear-capable tactical aircraft to Europe. But the most significant possibility is a mobile intermediate-range missile system-cruise, ballistic, or a combination of both-designed for greatly reduced vulnerability and able to match the Soviet SS-20 by threatening the Western U.S.S.R., as well as the Warsaw Pact countries, with a reliable theater-based attack accurate enough for counterforce purposes. This would restore the theater deterrent, and while it could be perceived as increasing any tendency to decoupling, would sufficiently enhance the theater's self-contained capabilities to outweigh that consideration.

This European situation is quite comparable to the problem of Minuteman vulnerability. That is, an element of the overall NATO nuclear force can be seen as threatened by Soviet developments even though, as in the case of Minuteman, the operational feasibility and rationality of an attack is highly questionable. And the response, taking the weapons-building route, would be to create a new NATO-European system, analogous to MX, as a counter.

It must be noted that establishing a NATO IRBM or IRCM force in Europe would create major problems. The force would be an answering threat to the Warsaw Pact, granted. But on the NATO side, it would generate very difficult and divisive problems of control, deployment, coordination, security, financing, modernization, and support, like those that became evident in the early 1960s during consideration of NATO MR/IRBM and the NATO Multilateral Force. It would also be very expensive, diverting resources from more productive ends, military or civil. It would probably exacerbate European concerns about decoupling U.S. strategic forces from European defense. On the Soviet side, it would clearly be a project to oppose strongly, surely a source of enhanced NATO-Warsaw Pact tensions and hostility, and in due course a stimulus to a further countering system.

Agreements that would prevent a new theater nuclear weapon cycle or, better, commence the reduction of the opposing systems, would clearly be the better road.

Negotiating such agreements would be a matter of great complexity. In the first place, they could not be negotiated directly between the United States and the U.S.S.R. The interests of our NATO allies are profoundly and directly involved; they would have to participate fully. Warsaw Pact nations would also have to join in, even if their participation were more cosmetic. SALT could not be the appropriate forum for a multilateral operation, even though its concerns would overlap at the boundaries (cruise missiles, Backfire bombers). Neither would the Mutual and Balanced Force Reduction discussions in Vienna be a satisfactory locale; MBFR would likewise overlap the new negotiations (tactical nuclear weapons), but its basic thrust is quite different. It would not be rational to load the MBFR forum with a separate and important new task, requiring a different kind of expertise, just as its work, long comatose, is showing signs of progress. In sum, an entirely new multilateral negotiating forum would be needed, coordinating with both SALT and MBFR. There would be an exponential increase in negotiating difficulties.

Further, the elements of the agreements would be very difficult to fix in an evenhanded way. Theater nuclear forces in Europe form a continuum from deep-strike elements to battlefield weapons, from forces supporting strategic strike plans to those integrated into conventional forces. It would be visionary to try to attack the whole problem at once, yet, on the other hand, it would be hard to control one element without tilting others. The problem, and it would be complex and time consuming, would be to narrow down to specific issues where substantive, balanced agreements were possible and which made strides toward stability and toward mutual reductions in theater forces. Clearly, the theater negotiations, like SALT, would have to be a continuing process-agreement after agreement over time.

It is evident that much study and discussion, both national and international, will be needed to find a consensus on both the negotiating mechanism and the elements to be negotiated. Some outlines of the problems of substance can, however, be laid out. The objective, to repeat, should be to stabilize the theater nuclear relationship, to prevent deployment of major new systems or major modernizations or reinforcements on either side, and to undertake balanced reductions. The factors that would create the possibility for agreements now and in the next few years-the factors that open the window-are, in the first place, the heightened concern in NATO over increasing Soviet theater capabilities at a time of U.S.-Soviet strategic equivalence, balanced by predictable Soviet concern over prospective NATO programs produced in response; and, in the second place, the new and prospective weapons systems themselves, coming in the same weapon cycle: the SS-20, the SS-21 tactical missile, theater cruise missiles, enhanced radiation warheads, the extended-range Pershing, the general program to modernize NATO tactical nuclear elements. A related program, so far pushed aside in SALT but ultimately inescapable, is the question of U.S. forward-based systems, balanced by that of the Backfire bomber and other Warsaw Pact theater systems.

A special group has recently been established under the NATO Council, in Brussels, to explore theater nuclear arms control possibilities. It was set up, characteristically enough, some two years after a similar group started work on the arms-building route. As yet, the various national views have not coalesced, much less those of the Alliance, and the issue is not being given much priority. Obviously, there is as yet no contact with the other side on the matter, and the hard and time-consuming business of establishing working negotiations-getting mutual understanding and broad agreement on the general substance of matters to be negotiated, specifying the outlines of the problem, the order of priorities, and getting some feel for the nature of each side's preliminary views and proposals-remains to be planned, much less carried out. These matters took years in SALT and in the Mutual and Balanced Force Reduction talks.

The last ten years of intensive work in those negotiations have greatly extended the communications, the common vocabulary, and the informed work force in East-West arms control matters; theater nuclear negotiations will profit from what has gone before. Still, quick results in the European theater are not to be thought of. On the other hand, the deepening concerns, the threats, the counterthreats and the expensive hardware programs, all leading to a major, unstable climb to at best an equally unstable plateau, are clearly in sight. It is time for a substantial effort toward the arms control alternative. The factors are favorable if the negotiators can catch up with them.

VIII

Three other arms control agreements which bear on the strategic relationship and the NATO-Warsaw Pact balance are currently under negotiation: a comprehensive test ban, a ban on anti-satellite weapons, and mutual and balanced force reductions. All would be killed, or at least indefinitely delayed, by failure to ratify SALT II. Given SALT II, however, all three are generally promising. Each would be a valuable step. Other possibilities can be suggested, or will emerge.

The projects discussed in the earlier sections, plus these, could together form the basis for a broad U.S. campaign of nuclear and East-West arms control. The key triggering item is solution of the problem of ICBM vulnerability. It is the one for which the various influencing factors-the window conditions-are most immediate and unmistakable. Success with it would ripple out, surely to a valuable SALT III, and also to positive momentum for the others.

No one can guarantee success, in whole or even in part, for such a major program of arms control efforts. Still, many factors justify the attempt. If it fails, the arms-building route, however unpalatable, remains. Success would make our security, our allies' security, and that of the whole world measurably greater and more stable. Hostility and fear would be reduced and large resources saved.

Last but not least, whether such a program were to fail or succeed, it would be good for this country that we had made the effort. It would be good for our view of ourselves and our confidence, now in disarray, that we still follow our best national impulses; it would be good for the world's view of us if we publicly dedicated ourselves to a large-scale effort to stem the momentum of the arms race.

There is, however, no reason to expect failure. The time is ripe; the international and military factors are favorable. A window is opening.

1 The "Statement of Principles," essentially the initial agenda for SALT III, agrees on continuing negotiations to: (1) limit and reduce numbers and qualitative characteristics of strategic weapons; (2) strengthen strategic stability by limitations of the most destabilizing arms; (3) ensure adequate verification by national means plus, where needed, cooperative measures. The agreed objectives are substantial reductions in numbers, limitations on new development and modernization, and agreement on cruise missiles, air-to-surface ballistic missiles, and mobile ICBMs.

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  • Vice Admiral John Marshall Lee, U.S.N. (ret.), in addition to holding senior command and staff positions in the Navy, was Assistant Director of the Arms Control and Disarmament Agency, 1970-73; Vice Chairman of the U.S. delegation to the U.N. Military Staff Committee, 1969-70; and Vice Director of the International Military Staff of the NATO Military Committee, 1966-69.
  • More By Admiral John M. Lee