Understanding the forces behind the SALT II controversy

President Reagan has thrown down the gauntlet on SALT II. Declaring that he will no longer be bound by the arms control agreement, he has drawn sharp words from Moscow and stirred controversy among the Western allies, in Congress, and among many American voters. Here are some questions and answers to help clarify the growing public debate:

What is the SALT II agreement?

The comprehensive accord resulted from the second series of Strategic Arms Limitation Talks and was signed by the Soviet Union and the United States in 1979. It set a total ceiling on offensive nuclear arsenals. It also established numerical subceilings of 820 for multiple-warhead intercontinental ballistic missiles (ICBMs), 1,200 for multiple-warhead ICBMs and submarine-launched ballistic missiles, and 1,320 for a combination of missiles carrying multiple warheads and bombers with air-launched cruise missiles.

Why is the agreement at issue?

The accord was never ratified. After the Soviets invaded Afghanistan, President Carter asked the Senate not to proceed with ratification. Even if it had been ratified, it would have expired in December 1985.

Upon assuming office, President Reagan made clear the US would not ratify the treaty, which he had called ``fatally flawed.'' But the President established a policy of abiding by the terms of both SALT I (which expired in 1977) and SALT II as long as the Soviets showed equal restraint.

Has the SALT regime worked?

Supporters say yes. Both SALT I and SALT II have affected the force structures of the superpowers. Both sides have planned within the SALT ceilings and probably would have deployed more weapons without the agreements.

To stay within the SALT boundaries, the Soviets have dismantled more than 1,000 land-based and sea-based missiles and 14 Yankee-class submarines since the early 1970s. The US has destroyed eight Polaris submarines and will complete retirement of its Titan missiles in 1987. Last year it dismantled a 16-missile Poseidon submarine when the seventh Trident submarine went out for sea trials.

Through 1987 the Soviets would have to dismantle more weaponry than the US to stay within SALT II.

Why is the administration raising the issue now?

The eighth Trident submarine began sea trials in late May, which would have put the US on the verge of exceeding the SALT II subceiling of 1,200 multiple-warhead missiles.

What did the President do?

He ordered that two old Poseidon subs be scrapped. But he said the decision was made for military and economic reasons and not because of SALT II, as it would cost too much to refurbish the aging subs. Henceforth, the President said, the US will base its arms decisions not on the SALT II terms but on the perceived Soviet threat and US military needs. This is a fundamental shift of policy.

Has the US then breached the treaty?

No. Scrapping of the two Poseidons keeps it within de facto compliance of SALT II.

Does this mean the US plans to upset the rough offensive balance established by SALT II and escalate the arms race?

That is not clear. The President stated the US would not deploy more strategic nuclear delivery vehicles (missiles or bombers) or ballistic missile warheads than the USSR. But the Soviets have more ballistic missile warheads than the US (while the US leads in nuclear-armed submarines, bombers, and cruise missiles), leaving the door open for additions of ballistic warheads to the US arsenal.

Also, Reagan did not say he would limit the number of bombs and cruise missiles carried by bombers. The US has a huge advantage in this area.

When is the next potential breach of SALT II?

At the end of the year. The US will be outfitting the 131st B-52 bomber with cruise missiles, which will put it over the treaty limits.

What will the President do?

He said he would go ahead with deployment of more cruise missiles unless the Soviets took ``constructive steps'' in the arms control field. He has left himself room for maneuver, however. He could continue to arm the B-52 bombers with cruise missiles but dismantle two more Poseidon submarines on grounds that they, too, are uneconomic. This would still keep the US within SALT II.

Why is Reagan opposed to SALT II?

The goal of the accord was to put a numerical cap on escalating nuclear arsenals not reduce them. So SALT II has made possible an enormous buildup of Soviet forces, which he believes now weakens the US strategic position. The President also charges the Soviet Union with violating the arms control agreements.

Does the Soviet buildup threaten the US?

Most Western arms experts say there remains a rough nuclear balance because the US continues to have the edge in nuclear-armed submarines, bombers, and cruise missiles. But the modernized Soviet land-based missile force is said to pose a first-strike threat to American ICBMS. The new MX missile, permitted under SALT II, is targeted to that problem.

If the Soviets are in fact violating SALT II, why has the US not repudiated the agreement long ago?

Administration supporters of SALT II, including the State Department and the Joint Chiefs of Staff, have supported compliance with the accord because it has placed restraints on Soviet strategic forces that far outweigh concern about violations. The Soviets have complied with the most important part of the agreement, the weapon numbers limits.

Without SALT II, say its supporters, the Soviet Union is in a better position than the US to add to its nuclear arsenal. By merely deploying more warheads on its heavy SS-18 missiles (now permitted 10 warheads each under SALT II), the Soviets could add more than 6,000 warheads to its stockpile. The US could not match such a buildup.

Why is the President then repudiating the treaty?

His advisers are deeply divided over the issue. Civilian leaders in the Pentagon and other administration conservatives have long wanted to do away with SALT II, contending that the US is better off without an arms control agreement. Their arguments find a resonance with Reagan, who wants to achieve sharp reductions in nuclear weapons rather than ratify the present huge arsenals.

Some administration officials hope that the President's decision will force Moscow to negotiate the deep reductions he seeks.

Are the Soviets likely to meet the President's conditions for reconsidering his SALT II decision?

Arms experts doubt the Soviets will unilaterally reduce their nuclear forces or stop treaty violations without some quid pro quo. But there are new signs of possible Soviet flexibility in the Geneva arms talks -- signs that emerged before Reagan announced a new SALT policy.

Is this the end of SALT II?

The situation is ambiguous. It cannot be ruled out that Reagan, having left himself wiggle room, will continue de facto compliance with the accord. Much will depend on what the Soviets do next, on whether there is progress in Gevena arms talks, and on whether there will or will not be another summit meeting. Alleged Soviet violations

As part of the SALT I process, the US and USSR set up the Standing Consultative Commission (SCC) to help settle treaty disputes.

The commission, comprised of delegates from both countries, has resolved a variety of compliance issues. But the US is alleging several Soviet violations or potential violations of the nuclear arms treaties that the SCC has not resolved. They are: SALT I Interim Agreement:

Violation: USSR is using former SS-7 intercontinental ballistic-missile sites as the basis for facilities for their new SS-25 ICBMs. The treaty does not permit reuse of sites that were deactiviated to compensate for new systems. Antiballistic Missile Treaty

Violation: The building of a phased-array radar near Krasnoyarsk, deep in the Soviet interior, whose siting and orientation violate the pact. The Soviets say the radar is a space tracking facility, permissible under the treaty.

Probable Violation: The Soviets have tested ABM components apparently designed to be moved from one location to another over a period of months. It would take years to move fixed ABM facilities. The treaty prohibits development, testing, or deployment of mobile, land-based ABM components. SALT II

Violation: Soviets have built the SS-25 and the SS-X-24, which violates a provision allowing each side to flight-test and deploy one new ``light'' ICBM. The Soviets said the SS-X-24 was their new ICBM and claim the SS-24 is a permitted modification of an older ICBM.

Violation: The number of Soviet strategic nuclear delivery vehicles exceeds the initial ceiling of 2,400 for each side.

Violation: The Soviets have been heavily coding telemetry during missile tests, impeding US efforts to verify Soviet compliance with the treaty. The treaty bars deliberate concealment techniques that hinder verification.

Violation: The Soviets have not allowed the US to ``see'' planned launchers for the SS-25 during testing or to verify that the launcher launched the missile. This runs counter to the SALT II provision prohibiting concealment of the association between missile and launcher during tests.