IN A WAY, the administration has already succeeded beyond its wildest dreams in the effort to win Senate approval of the SALT II treaty. Here it is barely midsummer, and a growing chorus of important voices (whose opposition had been most feared) is saying that the treaty itself is no villain, that its ratification is almost a matter of indifference, that the fundamental strategic problems that most concern them are in fact beyond the power of the treary, as such, either to remedy or even make much worse. That is necessarily a foreshortened and somewhat distorted version of the positions taken by Henry Kissinger and Georgia's Sen. Sam Nunn, as well as some others on the skeptical middle-right. And each has sketched out certain special hesitations and recommendations and objections of his own. But it is still fair to say that in some unexpected and consequential sense both have pronounced the treaty neutral - meaning that its significance and therefore its merit can only be judged in terms of the use the administration plans to make of its relatively permissive terms.

In this they were accepting a line of argument the administration has been plying with ever greater fervor for months: that the SATL II accords are neutral and harmless so far as the changes in the strategic balance that worry a lot of senators and others are concerned. Yes, it is all too unfortunately true, this argument goes, that for a period in the early to middle (or late) 1980s the American land-based ICBM force will be vulnerable to destruction by Soviet attack. But, in the context of ratifying the accords, the principal reply has not been that this is an unrealistic fear of that the United States wuld still have enough nuclear explosive power available to counterattack mercilessly and thus to deter in the first place (the standard answers). Rather it has been thet the treaty under consideration did not cause the pending "sitting duck" status of the Minuteman force and, most important, does nothing to prevent our takin steps to remedy this status. The argument runs that the proposed development of the new MX mobile land-based missile and some other military initiatives, all countenanced by the accords, will provide the remedy.

To the evident discomfiture of some of the treaty's supporters in and out of the administration, prominent critics such as Mr Kissinger and Sen. Nunn have now accepted this construction of the treaty's inherent meaning and merit - almost. The difference is that they are insisting, as a condition of support, on tougher military and political measures, and they want them in hand before the SALT accords are approved.

The administration asked for this. There was never any prospect - nor should there have been - of its being able to have the SALT accords discussed in that detached, antiseptic, "no linkage" way some of its spokesmen originally seemed to be insisting on, as if the treaty and protocol werr self-contained and self-sufficient and self-enforcing documents that enjoyed a clean and innocent life apart from conduct of the armed-to-the-teeth and not-very-friendly parties that had signed them. So it was always in the cards that the SALT documents would be considered in the context of larger Soviet-American relations and of Soviet behavior. And once the administration (properly) enlarged the whole debate to include the changing strategic relationship and its own plans (that is, the MX) for dealing with it - they could harldy expect to keep others, like Mr Kissinger and Sen. Nunn, from pursuing this line of thought - to somewhat different, or at least more stringent, conclusions.

You do not have to believe in all the improbable-to-preposterous scenario warfare the arms specialists set forth to believe that the conditions the worriers describe, starting in the early 1980s, are worth worrying about. That should be a central focus of the arms debate. And even though the treaty is "neutral" in the sense of not ruling out steps to change these conditions, there is nothing wrong with making the treaty's acceptance contingent on certain undertakings from the administration about how it will act to reduce the high risks inherent in a situation where the American land-based ICBMs are known to be theoretically vulnerable to attack by the other side and of potential military use only if they are preemptively fired at the war-edge of an international conflict.

We think the critics are right to make evidence of an authentic and active effort to reverse this situation a central issue of treaty ratification. Our confidence does not extend, however, to the particular weapon system that has been selected to do the main part of the job. In gaining the approval of SALT 1, a commitment to the Trident submarine - premature and now conceded by many to have been wrong - was undertaken. The MX system, along with the implausible basing modes being discussed for it, has as many serious and impressive critics (on both sides of the debate) as the Trident had, and the MX case looks to be even stronger.At the very least, the momentum toward acceptance of this system should be slowed and various proposed alternatives weighed. It is correct to say that SALT II can only be reasonably considered in the context of the changing U.S.-Soviet strategic relationship and how the American land-based missile force can be made more stable and secure over the next decades. There are far too many question marks surrounding the MX to suggest that it should have the principal part in this urgent project.