A Summit Both Sides Need : * May 30 Now Becomes the Deadline to Get Things Done

The most important signal sent by the agreement of the U.S. and Soviet presidents to meet in Washington for five days starting May 30 is the most obvious: Both sides accept that efforts to continue improving superpower relations are of primary importance. Until this week’s American-Soviet ministerial-level talks nailed down the details for the summit, however, the immediate future of those efforts was shadowed by doubt.

Bush Administration officials, anxiously eyeing events in the Baltic states, were hinting that the President might have to postpone his long-discussed meeting with Soviet President Mikhail S. Gorbachev. Now, after hearing assurances from Soviet Foreign Minister Eduard A. Shevardnadze, the Administration indicates its concerns have subsided. That’s encouraging news, if not yet the final word. Seven weeks remain before the scheduled summit. How the Soviets behave over that period toward the independence movements in Lithuania and Estonia could be all-important.

Not least among the values of a Soviet-U.S. summit is that it offers a target date to make headway on issues long under negotiation, as well as a dramatic forum for heralding achievements. The outstanding bilateral issues at the moment involve weapons and armies. Both sides want to resolve details holding up a pact to reduce their long-range nuclear weapons. With hard work, there could be a treaty by year’s end. Both want to move ahead on an agreement for a phased reduction in chemical weapons stocks. Both are eager to cut conventional forces in Europe.

This is an agenda of considerable promise for reducing tensions and for permitting cuts in military budgets. Agreement on these issues probably would come sooner or later even in the absence of a summit--and even if sharp controversy erupts over Soviet policy in the Baltic states. But, at the very least, the atmospherics of the relationship will surely be affected by what unfolds in the Soviet Union’s westernmost republics.

Gorbachev promises no use of force to repress the Baltic independence movements. At the same time, he and the Soviet Legislature are weaving a cocoon of legal restraints aimed at making independence all but impossible. Congress, watching closely, grows restive; Soviet heavy-handedness would lead it to demand punitive measures. The Administration, caught between sympathy for Baltic self-determination and support for Gorbachev’s reform efforts, can only measure its words with the greatest care. The summit, for now, is on, and welcome. But seven weeks is a long stretch, and the situation remains tense and unsettled.