In the course of forming an opinion of the merits of SALT II, I have been impressed by the damage to its case resulting from a fallacious assumption. It is that parity in strategic forces can be achieved through rough equivalence of numbers of strategic weapons, or, more accurately, strategic launchers. If it can be shown that this assumption is incorrect and that equality in numbers does not assure "equivalent overall military capabilities" -- a requirement set by the administration for an acceptable arms-control agreement -- the case for SALT is in serious trouble.

A mere count of strategic weapons is wholly inadequate to measure the relative effectivenss of opposing forces. The only military capability possessed by such weapons is the ability to destroy hostile target on order, and hence, the only meaningful measure of their value is their target destruction potential. The latter derives not only from numbers of weapons but also from such things as the accuracy, reliability and throwweight of weapons, their survivability under attack and the number and nature of the targets they must destroy.

Analytic studies of the relative losses that would be suffered by U.S. and Soviet forces in a major strategic exchange usually indicate that the U.S. side would be at a serious disadvantage. This is because we must assume that a nuclear exchange would be initiated by a Soviet first strike, probably directed at our exposed ICBMs. In this case, we would have to expect to lose a large part of these weapons, perhaps up to 80 percent or more at the height of the Soviet destructive capabilities in the 1980s. Moreover, if we wished to retaliate against their unfired ICBMs, we would be uncertain which missiles had been launched and which remained in silos ready for a second salvo. To do maximum damage to the remainder, we would have to fire upon all known silos and, in so doing, waste many American weapons on empty holes.

Similarly, if our retaliation extended to urban-industrial targets, we would need to expend many more weapons than the Soviets to achieve equivalent damage on similar targets. This is because the larger number and greater dispersion of such targets in the Soviet Union and the better protection afforded them by Soviet air and civil defense measures.

Thus, it is clear that U.S. forces, to match Soviet destructive capabilities, would need a considerable superiority in numbers of weapons to compensate for these disadvantages. Since SALT II obviously contains no such compensations, it cannot rightfull claim to establish essential equivalence in the preeminent measure of strategic power: target destruction potential. Accordingly, parity based on numbers alone is revealed as a dangerous fallacy, one which entails serious consequences.

Since the treaty purports to establish parity in military capabilities yet does not, its ratification would mislead our country and its allies as to the true balance of forces resulting from it -- a misapprehension unlikely to be shared by Soviet leaders, who are openly delighted with its text in the present form.

Further, ratification would validate and perpetuate the numbers fallacy for all future arms control treaties since we would find it hard to reject at a later date or to persuade the Soviets to abandon a standard that they must perceive as advantageous.

Finally, since our government following ratification would be expected henceforth to follow a military policy consistent with the treaty, in logic our strategic programs would be designed to catch up and keep up with our Soviet rivals in the strategic field in every way permitted by its terms. We could expect such programs to include not only an MX missile to match the best of the Soviet ICBMs but also probably a new bomber to offset the Backfire along with plans for expanded air and civil defense. All this would cost a great deal of money that, in times of economic stringency like the present, would be raised largely at the expense of our under-strength non-nuclear forces. The result could be a serious imbalance of force structure to the detriment of highly important tasks involving the support of allies, the protection of sea lanes and the assurance of access and undisturbed trade with essential overseas sources of oil and other important raw materials.

Such are a few of the possible consequences of the numbers fallacy. As long as it is the accepted formula for determining military needs in the strategic field, we shall be condemned to a mindless numbers race whether or not SALT is ratified. Only if we insist on basing our weapons requirements on the need to perform tasks of unchallenged importance to our security -- in most cases the destruction of certain designated target systems -- can we know with reasonable certainty what and how many weapons we really need either for deterrence or for retaliation. As an added plus, a strategic policy so conceived would not depend on numbers decisions made in Moscow.

Does the numbers fallacy with its consequences constitute a fatal weakness for SALT, one justifying its rejection? Probably not, if the administration can translate the numbers of weapons permitted by the treaty into terms of destruction potential and then produce convincing evidence of the adequacy of the latter against all majro Soviet target systems under all likely conditions. I suspect that the adequacy probably exists, but the Senate and the public are surely entitled to the evidence.