Rejection of SALT II having been a major element of President Reagan's campaign, it is clear that something new is required. Eugene Rostow, new director of the Arms Control and Disarmament Agency, opened with the suggestion that the acronym SALT-- Strategic Arms Limitations Talks--be changed to START-- Strategic Arms Reduction Talks.

The Carter administration had somewhat the same idea. In 1977 it proposed substantial reductions to Moscow, including the elimination of the Soviet SS18 heavy missile. Soviet suspicion that the careful trade-offs of the 1975 Vladivostok meeting were being revised in the United States' favor caused a sharp rejection of the Carter proposals. Gen. Edward Rowny's recent revival of this approach is not likely to meet a better reception, nor is the administration's new effort to measure relative forces by throw-weight and megatonnage rather than missile launchers and warheads.

The 1977 experience gives warning that any proposal to replace SALT II must be carefully prepared to appeal to the Soviet Union as well as to the United States.

One of the major causes for the failure of SALT II and the current determination of the United States to strengthen its nuclear forces is the danger that the Soviets are developing a first-strike capability, some years ahead of earlier intelligence projections. It has been the focus of great concern, leading to proposals such as the MX missile and its shell-game basing system, possible revival of anti-ballistic missile defense requiring abandonment or modification of the 1972 ABM agreement, and farther-out possibilities such as active defense systems in space.

From the Soviet point of view, the same first-strike concern exists. Relatively recent increases in the accuracy of the American Minuteman III due to an improved guidance system, the substantially improved effectiveness of the new A-12 warhead and, of course, the prospects for a new MX missile clearly present the likelihood of an American first-strike potential, either existing or imminent.

We are thus in a situation comparable to that in the late 1960s, when the United States was well ahead in MIRV technology. The subject was omitted from SALT I, at the cost of seeing the Soviets not only catch but surpass us in the numbers of warheads placed on their new generation of missiles in the 1970s. We are currently somewhat ahead of the USSR in first-strike capabilities, but the Soviet progress is clear, as is the prospect that the two superpowers will face each other in the high noon of the 1990s with these hair-trigger arsenals, but still essentially equal in overall power.

In this situation, a real START could be made on one simple principle: The elimination of the first-strike potential of both the United States and the Soviet Union. The only first-strike potential existing or likely to exist in the near future comes from land-based intercontinental ballistic missiles (ICBMs). A simple no-first-strike environment thus could be achieved by an agreement to dismantle and eliminate all land- based ICBMs in observable stages. Each nation's technical means of verification--its intelligence systems--would ensure it that the other side was dismantling and eventually abiding by the mutual restraint.

In past years, this would have represented a most unbalanced reduction, since the Soviet Union would be required to eliminate some 1,400 such launchers (as against 1,050 American), which would leave it with a minor and not very effective submarine-launched ballistic missile (SLBM) fleet and a marginal strategic aircraft capability, compared to large U.S. capabilities in these two systems. In recent years, however, the Soviets have built up their SLBM fleet to a present total of over 950 launchers, are arming them with MIRV warheads and are deploying the Backfire bomber, which has the capability, although perhaps not the current mission, of intercontinental strategic attack. These improvements clearly provide the Soviet Union with more than an adequate nuclear capability for a certain retaliatory strike.

The United States SLBM fleet is currently being modernized by the Trident; the country retains an effective, although aged, B-52 fleet (which may or may not be modernized by the B1 or Stealth bombers), and is on the verge of a wholly new system of strategic range cruise missiles, air-fs, sea-fs or land-based, to continue our "Triad" capability of a certain response to Soviet attack.

None of these forces on either side has a first-strike capability. The SLBMs suffer certain inherent firing position inaccuracies and control problems, making them inappropriate for first-strike action. The aircraft and cruise missiles have such slow delivery rates that they also cannot be considered in this category. If SLBM accuracy should improve in the coming years to the point of threatening a first-strike capability, a START II could contain it.

The enormous benefits in mutual safety-- and savings--which would accrue to both nations from this decision are quite obvious. The MX and its mobile basing mode currently being discussed in the United States is estimated to cost up to $100 billion. The nation-wide ABM system, which was forestalled by the 1972 SALT agreement, was estimated to have cost between $50 and $100 billion, which was saved. Sums of at least this magnitude and, of course, prime technological talent in both nations could then be available for other purposes. The American defense budget for conventional weaponry could be increased to the degree that is certainly required and a real saving in defense costs nonetheless achieved. The Soviets might even put some of their savings into better industrial, agricultural and consumer investments for their people.

The key to this START is its clear benefit to both nations and its lack of any strategic advantage to either. Once again, it could prove that an administration with confidence in itself, its power and its principles can make major changes in policies that administrations with softer credentials were unable to make.