THINGS look set for a superpower pact limiting long-range nuclear weapons to flower in June. The United States and the Soviet Union have agreed on the central elements of a Strategic Arms Reduction Talks (START) treaty, as President Bush and Soviet leader Gorbachev affirmed at the seaborne Malta summit. When the pair meet on solid ground here in the US in three months, they will likely have a splashy ceremony on a START agreement in principle.
You never know, though - arms control is an unpredictable business. Some difficult technical details must still be resolved, and points considered settled could come unglued.
Last month the Soviet Union dropped its demand that a strategic weapons pact be linked to limits on the US Strategic Defense Initiative (SDI). But this issue has long been contentious, and in the US government ``people are crossing their fingers'' that it will not be raised again, says an administration official familiar with START progress.
In Geneva, US and Soviet negotiators are hard at it and will continue to work straight through to the June summit date. Even under the best of circumstances it will take them until late summer or fall to finish all the picky details of the long START treaty text.
START is a long-running set of talks, having begun under the Reagan administration in 1982. Unlike the conventional force talks, which have moved at diplomatic warp speed, START has been a long hard slog.
From the beginning, it has focused on two US-held principles: that unlike the SALT nuclear agreement, START should bring real reductions in nuclear arms, and should particularly limit big, heavy land-based missiles, weapons judged destabilizing because they can destroy an adversary's arsenal with little notice.
The two sides have agreed to START ceilings of 6,000 strategic nuclear warheads, with no more than 4,900 on ballistic missiles. While this is billed as a 50 percent cut in weapons, complex counting rules mean it will be about a 30 percent actual reduction, with each side retaining more warheads than the 6,000 limit.
``There are lots of little ways around the limits, so the real arsenals will be 9,000 to 10,000 warheads,'' says Jack Mendelsohn, deputy director of the Arms Control Associaton.
On delivery systems for the warheads, each side will maintain no more than 1,600 ballistic missiles and heavy bombers, under proposed treaty provisions. Of the missiles, no more than 800 can be mobile. The Soviets have agreed to halve their force of 308 ``heavy'' SS-18 missiles.
For years progress on the treaty was held up by bitter differences on how to treat sea-launched nuclear cruise missiles (SLCMs), and by the Soviet insistence that for a treaty to make sense it had to be linked to restrictions on strategic defense weapons, such as those the US ``star wars'' program aimed to develop.
These obstacles began crumbling last fall as it became apparent Gorbachev wanted fast movement on arms treaties. When Secretary of State James Baker III visited Moscow in February, he left with a Soviet agreement that SLCMs would be cut out of the treaty. Instead, each side will issue declarations of how many SLCMs they will deploy. The Soviets agreed to drop a demand for START-star wars linkage, but reserve the right to pull out if they think a star-wars test has violated the Anti-Ballistic Missile Treaty.
Though this completes an outline of a treaty, difficult technical differences remain, many complicated enough to cause eye-glazing even in dedicated diplomats.
It is not yet set, for instance, what sort of air-launched cruise missiles will be covered by the treaty. The US wants only longer-range ALCMs included; the Soviets would limit those with ranges as short as 600 kilometers.
Negotiators have not settled on rules for counting the number of warheads on any future missile type. Verification provisions have yet to be agreed to. The duration of the treaty is still an issue.
Still, in Washington the treaty is considered practically a done deal. This is seen in criticism of the administration's START work, which has switched from ``you're not moving fast enough'' to ``you didn't do it right.''
Proposed treaty counting rules on bombers have come under congressional fire, for instance.
By counting each bomber as one nuclear warhead, no matter how many bombs it can carry, START would encourage the superpowers to beef up bomber forces even as missiles are controlled. As slow-flying bombers are not as threatening as missiles, that would be fine - except budget constraints mean the US is unlikely to build expensive B-2s to take advantage of the loophole.
``We're heading for a START agreement that is potentially out of sync with where the force is going,'' says Rep. Les Aspin (D) of Wisconsin, who chairs the House Armed Services Committee. Attention is turning START 2. The Soviets are outlining START 2 should accomplish.
Because it will still leave the superpowers with thousands of nuclear weapons, START 1 ``is not really going to have an affect on crisis stability,'' says John Steinbruner, director of foreign policy studies at the Brookings Institution. ``But it puts in place a political and regulatory structure for a follow-on agreement that might.''
Second of three weekly articles