Soviet negotiators in the Geneva talks have formally proposed the 25 percent cut in strategic nuclear delivery vehicles that Soviet leader Mikhail Gorbachev advanced publicly two months ago.
But according to special arms adviser Paul H. Nitze, who told reporters about the Soviet offer at a breakfast meeting yesterday, neither this Soviet gesture nor another recent shift in the Soviet bargaining position is enough to advance the discussion in Geneva, which "isn't making a great deal of progress."
Reiterating Reagan administration policy on the need for further Soviet concessions, Nitze said it will take "a new decision" by Gorbachev and the Soviet collective leadership to lead to a breakthrough in the talks.
The veteran U.S. negotiator expressed doubt that such a major shift will come this year.
Nitze and other U.S. officials said the recent changes in the Soviet negotiating posture in Geneva were restatements of offers initially made to the United States during President Reagan's first term.
Nitze said the Soviets seem to be responding to public relations requirements in Europe and Asia, with no evidence that they are altering their basic demand for a ban on research and development of the U.S. "Star Wars" program as a precondition for all agreements.
Gorbachev announced April 26 in Warsaw, "We have already suggested that both sides reduce strategic offensive arms by one-quarter by way of an opening move." He added that "we would have no objections to making deeper mutual cuts." Gorbachev also added what seemed to be a condition, saying, "All this is possible if the arms race does not begin in space."
The White House and State Department immediately responded to the speech by saying that no such Soviet offer had been made in the first round of Geneva negotiations, which began March 13 and ended April 23.
Nitze said yesterday that in the second round of talks, which began May 30 and is continuing, the Soviet negotiators have said little more than Gorbachev said in Warsaw, and they continue to refuse to bargain on offensive cuts until an agreement has been reached on space weapons.
The proposed 25 percent cut, Nitze said, appears to be a reference to the 1983 Soviet offer to set a ceiling of 1,800 strategic nuclear delivery systems, sometimes referred to as "launchers," for offensive arms. The term refers to missiles and airplanes.
A higher limit, of 2,400 launchers on each side, was agreed to in the unratified SALT II treaty. Nitze said the actual Soviet strategic arsenal is estimated to be about 2,500 launchers.
The "one-quarter cut" proposal is "not a very attractive thing" and "can be a counterproductive thing," said Nitze, because it refers only to the launchers, not to warheads or the size of warheads. The Soviets, he suggested, could reduce launchers but still increase their strategic arsenal by adding more warheads to their missiles.
Nitze said he believes that Moscow made this new offer believing that it would have "a positive impact" on the worldwide view of the U.S.S.R. and its willingness to negotiate in good faith.
The other recent change in the Soviet bargaining position, foreshadowed in a May 29 Gorbachev speech, was to offer a freeze on Soviet medium-range missile deployments in Asia in the context of an overall arms control agreement. The Soviets had expressed willingness to negotiate such a freeze in earlier negotiations but in this year's Geneva talks reportedly insisted on "no restraints" on such Asia deployments.
At issue are Soviet SS20 missiles capable of hitting both European and Asian targets. Asian countries have expressed fear that even if the Soviets removed some SS20s from Europe, they would simply move them to Asia.
Nitze charged that Soviet shifting on Asian missiles was "so outrageous it had begun to backfire," especially with China, Japan and Western European nations. The recent shift, he said, seemed intended "to limit the danger coming from an untenable position."