DETERRING NUCLEAR WAR 4; THE IMMEDIATE ISSUES

The crucial, immediate issues in the 1980s strategic debate will involve SALT II ratification, the mobile ballistic missile, and the anti-ballistic missile. A scorecard would read something like this:

SALT II

Old arms-control adovocates -- those who haven't undergone some conversion from the Soviet Union's unrelenting military buildup, invasion of Afghanistan, and persistent refusal to acknowledge either the virtues of assured second-strike or the security fears of nations bordering on the Soviet empire -- have been reduced to lying low and salvaging what they can of the signed but unratified SALT II treaty.

Given the Soviet intervetions after SALT I in Angola, Ethiopia, South Yemen, and Afghanistan, dispirited American arms-control proponents no longer view SALT as the cornerstone of a broader East-West political detente. They do contend negatively, however, that a failure to ratify SALT II would remove one element of restraing, predictability, and risk management at a time when this constraint is most sorely needed. Alton Frye, Washington director of the Council on foreign Relations, declared in the summer issue of Foreig Policy, "The entire process of strategic restraint in which the two countries have invested so heavily is in danger of collapsing."

More specifically, arms controllers contend that SALT II's restrictions on the number of warheads on monster Soviet warheads (which otherceiling on total Soviet warheads (which otherwise could grow to double America's arsenal by 1985) , and a ban on encoding of missile-test transmissions -- as well as SALT's quantitative limit on the missile race in general -- would enhance Western security. They point to further advantages in the treaty's requirement that the Soviet Union dismantle 104 missiles or bombers immediately and 150 more by 1981 (in contrast to a reduction of only 33 on the US side). They therefore urge Senate ratification.

SALT opponents, on the contrary, object to the exclusion of the Soviet Backfire bomber as a strategic weapon and to the inequality of the treaty's approval of the existing 308 Soviet heavy missiles but prohibition of any American heavy missiles. (The latter disparity arose because in the past Washington deemed heavy missiles useless militarily and refrained from building them. The dramatic improvements in MIRV accuracy, however, now give a new significance to the 40 warheads that could be attached to a Soviet SS-18 missile that is 10 times the size of America's three-warhead Minuteman. On this point doves retort that this is precisely the advantage of SALT II: that it holds the Russians down to 10 warheads per missile even on the SS-18 -- while allowing the US to put an equivalent 10 warheads on its new MX mobile missile.)

In any case, foes of SALT II tend to cite heavy missiles more as an example than as a central flaw of the treaty text as it stands. Now, as earlier, the opponents are perhaps less interested in the particular merits or demerits of the treaty than in the opportunity the SALT debate has provided for restarting America's military engine after the post-Vietnam decade of military disenchantment.

This attitude explains the original deal the Carter administration tried to strike of buying SALT ratification with a sharp increase in overall military spending. It explains as well most of the polemics, Strategic Survey suggests, during the tortuous SALT debate in the Senate. These involved the Soviet brigade in Cuba, the general thesis that "you can't trust the Russians" (an argument that went well beyond the question of the specific adequacy of SALT verification provisions), and the final suspension of ratification with the Soviet invasion of Afghanistan.

Indications now are that a President Reagan would kill the SALT II treaty either by going back to Moscow for prolonged renegotiation or -- as Reagan adviser William van Cleave proposes -- by mothballing all strategic arms limitation talks for several years until the US is stronger militarily.

Indications are that a re-elected President Carter would try once more to secure the two- thirds Senate majority for ratification. Even if Mr. Carter retains office, however, ratification is dubious. MX

Once upon a time the mobile ICBM was a dirty word in the arms-control lexicon. After SALT I, in fact, Washington warned Moscow (which was then more interested in mobility than the US was) that any shift to movable missiles would be regarded as inimical to SALT. Mobile missiles would be destabilizing, the US held, because they would be all but impossible to count by satellite in verifying agreed ceilings on launcher numbers.

In 1980, however, the shoe is on the other foot. The side that is going mobile is the US, with its $30 billion-to-$40 billion (critics say more) MX now in the planning stage. (The Soviet Union has deployed a mobile ballistic missile in the intermediate range but so far as is known has not planned a mobile missile in the intercontinental range.)

The American change of heart follows from the new 1980s vulnerability of fixed land-based missiles. The MX is designed to prolong the invulnerability of the land-based ICBM by turning it into a moving and therefore less certain target.

Arms controllers initially opposed the MX for the old reasons, and also because the new accuracies promised to give the MX a first-strike capability that mobile missiles had previously lacked. When the Soviet Union moved to acquire an anti-silo first-strike threat of its own, however, and continued to build giant missiles well after Soviet accuracy and MIRVing made their huge size unnecessary for any discernible defensive purpose, the arms controllers had second thoughts. The virtue of prolonging the invulnerability of the American ICBM in the perhaps crucial early '80s by making the ICBM mobile seemed to contribute more to stable deterrence than an increased first-strike potential would detract.

(Resignation played some role in this acquiescence, too, as it became clear that the first- strike prerequisite of counterforce targeting could no longer be deferred and had in fact been routinely programmed into American targeting plans for years, irrespective of whether public policy was counterforce or countervalue.)

In addition, some fears of MX nonverifiability were allayed when a convoluted open-hole check was devised that might enable the rival superpowers' satellites to confirm that ceilings were not exceeded in random agreed counts of total launchers.

A few arms controllers have continued to resist the MX and advocate a more radical response to silo obsolescence in reducing the present ICBM-bomber-submarine "dyad." This idea has faded, however, after running into doubts about the future control and survivability of submarines, Air Force objections to the dismantling of the big Air Force ICBM program, and lack of Navy interest in the novel shallow-water submarines being proposed.

For different reasons neither hawks nor environmentalists are very enthusiastic about the MX -- and the local environmentalists in the American Southwest could yet defeat the project. At this point defense planners see no real alternative, however, and the current debate focuses less on the basic shift to mobility than on the MX's technical mode, such as the now-discarded "racetrack" system or the currently favored "loading dock" system. ABM

The anti-ballistic missile (which was originally conceived of as an area-wide city defense rather than a "hard point" missile defense) was severely restricted under the 1972 ABM treaty, on the vulnerable populations-invulnerable weapons theory of stability. Under this treaty each superpower is permitted only a token two deployments of defensive missiles to shoot down incoming missiles, with no more than 100 launchers in each deployment.

In the 1970s the ABM treaty was widely regarded as the most unambiguous success of the entire SALT exercise, in actually forestalling one corridor of the arms race rather than simply proclaiming a ceiling on already existing weapons stocks. This perceived success was hardly dimmed by the fact that the US decided, for purely domestic reasons -- technological difficulties and local opposition at prospective ABM sites -- to waive even its permitted ABMs.

Now, however, the ABM concept has been revived -- not as an area-wide city defense, but as a hard-point defense of one's own missiles against attacking missiles, and particularly as an adjunct to the MX.

The reasoning runs thus: If SALT II is not ratified and Soviet missiles are therefore not limited quantitatively, the planned MX would be subject to being blanketed by any Soviet first strike. (A greatly expanded MX would not be a feasible response, since it would be prohibitively more expensive and probably could not outpace the cheaper expansion of threatening Soviet warheads.) Some planners have therefore turned to the ABM -- or, as it is more specifically termed in this case, the ballistic-missile defense (BMD) -- as a possible defender of the MX against such a threat. This new possibility has come about largely through technological advances in the past eight years in sensors, electronics, and reduction of the size and cost of radars.

The hitch in all this -- apart from the doubts of some specialists as to the efficacy of any defense system that relies on vulnerable radars -- is that the US would have to abrogate or renegotiate (or violate) the 1972 ABM treaty to deploy the BMD.

For hawks -- who disliked the ABM treaty from the beginning -- this presents no obstacle. Sen. Jesse Helms, for one, is quite prepared to scrap the treaty when it comes up for review in 1982. The Republican platform, while not committing itself on the treaty advocates taking the initial step of intensifying ABM research and development (which is legal under the treaty, with specified exemptions).

Arms controllers generally do not oppose the BMD defense of the MX on substantive grounds, since whatever maintains the invulnerability of weapons is regarded as stabilizing. Some do argue, however, that the cost of abandoning a major achievement of SALT for a still dubious (and probably temporary) technological fix is too high. It would run the risk, they say, of unraveling the whole delicate process of reaching arms limitations agreements with the Soviet Union. If Washington withdraws unilaterally from a painstakingly worked out treaty when the treaty no longer suits it, then this sets a bad precedent for comparable unilateral retreats in the future by Moscow.

Some arms controllers further fear that the unpredictability of technological innovation might well lead the ABM down the path of MIRV. Originally MIRV seemed to favor the US military posture, but in the end it produced the silo obsolescence and greater instability we are experiencing today. Similarly, an ABM that could prolong US silo invulnerability (and thus superpower stability) in the early '80s could in the late '80s give the Soviet Union that comprehensive (and destabilizing) defense that the hawks fear.

At this point such arms-control reservations are dormant, however. Momentum lies with the BMD advocates, and the reservations would probably be reactivated only if the BMD encounters major technological or financial problems.