It may be disappointing but should not be surprising that SALT II contains only a modicum of arms control despite seven years of negotiations. It would be astounding if two such hostile rivals were to agree to sweeping limitations on their primary means of military security. The purpose of armament arrangements between two highly competitive great powers is quite different. It is basically a political agreement; to provide a margin of reassurance and thus add an element of stability to the general relationship.

The new SALT agreements set only some rough outer limits. U.S. forces will grow to 11,000-12,000 warheads and bombs and similar Soviet forces will double, from 5,000 to 10,000. Nevertheless, these limits compare not with ideal limits in theoretical treaties, but with the probabilities of no agreement.

Consider, for example, the problem of the potential ability of the Soviet Union to wipe out most of our ICBMs. The United States has two choices. We can develop a new ICBM in some "mobile" basing of about 8,000 alternate launch points for about 200 real missiles. The SALT limits on Soviet missiles and warheads make it exceedingly difficult if not impossible for the Soviet Union to launch an attack on this scale. (Indeed, proponents of the MX mobility should desperately want limits on Soviet forces.) The second choice is to set aside SALT and to race by producing more "aim points" than the Soviets can produce missile warheads. The United States could probably win, but it is not self-evident why challenging the U.S.S.R. to build the maximum number of warheads is preferable to limiting them.

There are, of course, several possible improvements in the agreements that would yield American advantages. Some of them have already been tried and have failed in negotiation. Nevertheless, the Soviets probably could swallow some amendments but not the most significant ones. It is almost certain that the Soviets would not agree to scrap the temporary ban on land- and sea-based cruise missiles contained in the treaty protocol (which expires at the end of 1981). It is also unlikely that they would agree to count their Backfire bombers in the aggregate ceilings of 2,400 and 2,250. (If by some chance they did count some or all of them, it would certainly mean that Moscow intended to upgrade the aircraft significantly and probably arm it with long-range cruise missiles - not an attractive outcome for the United States.)

Probably, the Soviets would agree that the United States could have the right to build 300 very heavy ICBMs as the Soviets themselves have done. But deploying the new MX missile accomplishes about the same result within the treaty as written. The Soviets would probably accept some hortatory language about verification. Clarifying the status of "mobile" ICBMs seems to have been accomplished in the Vienna discussions and would not have to be a treaty amendment in any case. Insisting that the treaty protocol expires at the end of 1981 as written is redundant but harmless.

Senators, however, need to weigh some fundamental questions in considering the merits of each individual reservation or amendment. What is the international impact of a test of strength with the president, or the cost of humiliating him by imposing a series of major amendments? What is the risk in testing the limits of Soviet tolerance? And, above all, do the changes have real strategic significance? No amendments being discussed will solve the problem of the vulnerability of our ICBMs, or redress the imbalance in Europe, or check Soviet-Cuban intervention in Africa. Nor will these issues be solved by outright rejection. One theory is that only by defeating SALT can we administer the necessary shock to the American people and warn the Kremlin. But then what happens? Would our allies support us? Would the Senate proceed to vote the necessary defense funds in the new post-SALT environment? Would the president acquiesce in his defeat? What would Moscow do?

It seems likely that we would find ourselves in a political and strategic limbo. The Kremlin might well continue talking, but its basic strategy would be to begin preparing for sharper competition and contention with the United States. They probably would not launch a new "arms race" but would wait for the presidential elections - much like the period after the collapse of the summit in May 1960. We could thus find ourselves in the unenviable position of abiding by the essence of SALT, without any of the binding provisions on verification, while circling in a political holding pattern until November 1980.

This doleful state of affairs would coincide with a period of increasing international turmoil. The Soviet leadership is in transition. Sino-Soviet relations are in flux. Europe is groping for a larger identity. The international economic structure is being radically altered. There is a tendency toward regional instability if not chaos. Is it in the interest of the United States to challenge the Soviet Union in these circumstances and, if so, to what end? To get a new treaty or to force a Soviet defeat?

Confrontation with Moscow may come in any case; SALT unfortunately does not guarantee better Soviet behavior. But defeating SALT certainly is a leap into the unknown.

We need to rise above the technicalities of arms control, verification, amendments and reservations and answer some basic political questions. Ironically, it was one of SALT's main critics, Sen. Henry Jackson (D-Wash.), who put the issue quite correctly in a recent speech, when he asked whether it was possible to achieve an accommodation with a totalitarian superpower through negotiated agreement. The SALT proponents cannot dodge this question by stressing the virtues of a given article in the treaty, or its verifiability, nor can the opponents take refuge in contrived amendments that defer the basic decision. In the end the Senate will be voting to send a signal to Moscow about the direction we wish our relations to follow.

It would seem that the prudent course is 1) to approve SALT with a minimum of change, 2) to use the post-Vienna period to continue the political dialogue that was started there, especially concerning the consequences of Soviet interventionism in critical regions, and 3) to look to our own defenses rather than build up illusory hopes about SALT III (which incidentally deserves much more sober consideration before rushing into negotiations). Soviet conduct at the summit suggests that a wide area of differences with the United States will persist and may even grow. But, at the same time, the signing of the SALT treaty suggests that both sides would prefer these differences remain within some bounds. Can we really expect much more? CAPTION: Illustration, no caption