Rarely in the history of arms-control negotiations have the two sides seemed so far apart.
Indeed, the Soviets and Americans are so far apart in their initial positions that the only safe thing to say about the strategic-arms talks beginning this week is that they are not likely to produce quick results.
Reagan administration officials are currently trying to cast the brightest possible light on this, looking for every conceivable glimmer of a positive response from the Soviets. But most experts expect the Geneva negotiations on reducing strategic arms, set to begin June 29, to be difficult and protracted.
In their statements at the outset, both sides are playing heavily to the public -- and to the West European public in particular -- for sympathy and support for their respective approaches. That does not necessarily bode well for arms-control negotiations; in the past it has been virtually impossible to negotiate complex issues in the open. For awhile at least, the two sides may produce more public relations than arms control.
At the same time, however, both sides may come under pressures within the next year or two that could push them toward an agreement. On the American side, it is likely to be pressure from the US and West European peace movements -- and the pressure of American and European elections. On the Soviet side, where public opinion counts for less, it will be the pressure of an American arms buildup and new US weapons deployments.
Just how concerned the American negotiators are about public opinion can be seen in the strong reaction of some US officials to a vote in the House Foreign Affairs Committee. On June 23 the committee called for a freeze in American and Soviet nuclear weapons. In endorsing this nonbinding resolution, the committee ignored White House and State Department pleas. The administration had argued that a freeze at current levels would lock the Soviets into a position of nuclear superiority.
''All those congressmen were up for elections this fall,'' said a State Department official. ''In the mail, they've had huge numbers of pro-freeze letters. . . . They're afraid people will vote against a representative who didn't endorse the freeze.''
In this official's view, if the trend continues, the Soviets will simply try to wait out the Americans in the arms-control talks. They will count on public pressure for an arms-control agreement building before elections, with the heaviest pressure of all coming before the 1984 presidential election.
''If we have to look over our shoulders at this kind of thing all the time while we're in Geneva, it's really going to cut into our options,'' said this official.
Edward L. Rowny, the retired Army lieutenant general who will be the chief US negotiator at Geneva, says he is counting on the development of new long-range US weapons and promised planned deployment of new medium-range American missiles in Europe to give the Soviets the incentive to compromise in the negotiations. General Rowny says he agrees that the Soviets are being asked to give up their advantage in land-based intercontinental ballistic missiles in the initial phase of a new agreement. But he argues that with new, more powerful US weapons being developed, the Soviets ought to have an interest in negotiating a cap on US strategic forces.
The Soviets have criticized the American proposal for suggesting deep reductions in land-based forces. But so far they have been reluctant to say they will not even discuss it. Some officials see this as a sign that the Reagan proposal has a certain appeal to both the American and European publics. But once the Soviets get into the Geneva negotiations, they will have a representative who is fully capable of pointing out in a trenchant way what the Soviets perceive to be flaws in the Reagan plan. Viktor Karpov, the chief Soviet negotiator to the Geneva talks, is described by one US official as ''a very shrewd, tough cookie.''
''He has a biting kind of wit, and can be very abusive when he wants to be,'' the official said.
If Mr. Karpov goes on the attack and the negotiations reach a deadlock, some US officials believe it may be possible for the two sides to negotiate so-called ''confidence building measures.'' These might ease some public pressure from the United States and Europe. Such measures, now being considered by inter-agency committees within the US government, would be designed to diminish the element of surprise and prevent an accidental nuclear war. They would include, among other things, a greater exchange of strategic data between the two sides and the provision of more advanced warning on nuclear-missile tests.
Some US officials think that an agreement on confidence-building measures might help improve the atmosphere for a summit meeting between President Reagan and Soviet President Leonid I. Brezhnev, possibly even by the end of this year. But the overall state of US-Soviet relations is almost as unpredictable as the arms-control talks. Just how unpredictable can be seen in a new Congressional Research Service study that examines three widely varying but plausible ''scenarios.''
Some experts think that the real progress in the Geneva talks will come when the two sides agree to complete secrecy. As it is, the two delegations are supposed to agree not to leak information in Geneva, while leaving senior officials in their respective capitals free to talk about the talks. That could be a prescription for more high-level playing-to-the-gallery.