The short-term gains from the talks last week between Mr. Reagan, Mr. Shultz, and Mr. Gromyko are apparent. They at least broke the ice between the United States and the Soviet Union. They allowed the President to espouse better relations and dialogue, and Mr. Gromyko to blur the image of Soviet intransigence and open a way out of the diplomatic dead end of their own making. Around the world many were reassured that the atmosphere was less tense.
But what will the talks mean for the longer run? Will they lead to improving relations and progress in arms control? There the outlook is more murky.
Objectively, more-normal relations and arms restraint would seem to serve the Soviets' interests. Recently, things have not been going too well for them at home or abroad. A decade ago, in their view, the ''correlation of forces'' was moving in their favor and compelling the US to accept detente largely on their terms. Now the US is rearming to offset their military buildup and starting the ''star wars'' defense initiative. Their rigid economy is slowing, creating strains in allocating resources for the military, investment, and consumers. The Soviet Union has almost no appeal as a model anywhere. Ferment and pressure for autonomy are increasing in Eastern Europe. Massive military power is the USSR's main achievement. A series of ailing and aged leaders has deprived it of strong leadership.
Under these conditions, the Soviets were angered and frustrated by Mr. Reagan's earlier rhetoric assigning them to the ash heap of history. That may remove one barrier to dialogue. But the remaining obstacles to progress, especially in arms control, are formidable:
1. Even if both sides were ready for real negotiations, working out mutually acceptable restraints would be slow and difficult. Proponents of a ''nuclear freeze'' may make the process sound easy, but that is gravely misleading. Moreover, there is no real consensus in the US (or the West) about objectives. Even radical cuts would leave both sides with huge nuclear arsenals and might not improve stability, which, in my view, should have top priority. There might be the makings of a bargain in a trade-off of ''space defense'' for cuts in large Soviet ICBMs.
2. Even if Mr. Reagan is now as eager for arms control as he says, the US will be hard put to develop realistic proposals if he is reelected. A new book by Strobe Talbott describes the bureaucratic infighting and lack of leadership that have prevailed heretofore under Mr. Reagan. The Defense and State Departments are deeply split, with the secretary of state apparently favoring arms control, though not well equipped to support specific proposals, and the secretary of defense and key subordinates strongly opposed. Only the President will be able to decide among the competing counsels. But that would require him to master the details of the alternatives and their consequences far more thoroughly than has been his wont. A trusted and qualified aide (like Gen. Brent Scowcroft) could help him in the process, but no one else can substitute for him in imposing decisions on zealous protagonists in such vital areas. Otherwise the US is likely to be stymied even if the Soviets should be prepared for serious negotiations.
3. But that itself seems highly doubtful. Until now, the Soviets have shown no sign of the kind of compromise that would be needed for fruitful negotiations. Apparently they hope to retain their present advantages and to concentrate on restraining the US buildup and especially the strategic defense (star wars) initiative. More-flexible positions would require a strong leadership, firmly in charge, which is also confronting the difficult economic problems.
For all these reasons, rapid progress seems most improbable. That will doubtless cause impatience and distress in the West. But it should not relieve the next administration from devising and putting forward proposals that will serve the interests of both sides by fostering greater stability. Whatever their immediate results, such proposals may promote debate within the Soviet Union and lay the basis for future agreements. It is important to restart dialogue and contact. Even if no headway is made, that can be valuable in avoiding dangerous missteps or misjudgments on either side.