Washington — Recent Soviet arms control proposals mean Mikhail Gorbachev may be ready for some serious talk, both President Reagan and his critics say. The Soviets appear to be signaling a new flexibility on certain nuclear-weapons issues the superpowers have quarreled over for decades. But after all the proposals and counterproposals that have passed over the negotiating table in Geneva this year, the key question remains the same, according to some analysts: Will President Reagan accept a treaty that would fetter research on strategic defenses?
``Without [some US give on the missile-defense question] there will be no progress on arms control,'' predicts James Rubin, research director of the Arms Control Association.
Last week the President went out of his way to sound soothing and optimistic about the state of US-Soviet relations, perhaps to help alleviate political pressure generated in Congress by his decision to all but abandon the second Strategic Arms Limitation Treaty (SALT II) limits. In a speech to the graduating class of Glassboro (N.J.) High School Thursday, Mr. Reagan said ``the Soviets have begun to make a serious effort'' on arms negotiations, and that recent proposals ``could represent a turning point.''
The proposals Reagan was referring to have been revealed in various Soviet forums over past months. In a June 16 speech Soviet leader Gorbachev publicly laid out the Soviet offers in detail.
When Gorbachev's latest words are combined with Soviet statements from earlier this year, say analysts here, it appears the USSR is offering interesting concessions on a number of fronts. These areas include:
Forward-based systems. For the most part, this term refers to US airplanes, based in Europe and on aircraft carriers, which are mainly intended for conventional missions but are also capable of carrying nuclear weapons. These planes have been a thorny issue between the superpowers since negotiations on the SALT I Treaty began in 1969. The Soviets have tried to get them included in any agreement; the US, insisting they are not strategic weapons, has fought to keep them out.
Forward-based systems were one of the final obstacles cleared before agreement was reached on SALT II. The Soviets agreed to drop this issue, among others, in return for heavy missiles being allowed by the agreement, treaty negotiators say.
During Reagan-era talks the Soviets have again been insisting that forward-based systems be counted as strategic weapons. In his June 16 proposals, however, Gorbachev agreed that the planes can be left out of any strategic treaty.
The Soviet leader did insist that the numbers of forward-based systems be frozen at current levels -- a position which, if not revised, would likely be unacceptable to the US.
British and French nuclear forces. The Soviets have also been trying since 1969 to get limits on British and French nuclear weapons included in US-USSR arms treaties. The US, saying it has no control over its allies' nuclear forces, says this is an issue it can do nothing about.
In January, when Gorbachev made his first sweeping arms-cut proposal of the year, he agreed that these weapons need not be counted in a superpower treaty. As with forward-based systems, though, he insisted that the British and French nuclear forces be frozen.
This is a doubly difficult proposition for the US. Not only does the US government have no ability (or desire) to enforce such a limitation, but both France and Britain are in the midst of significant modernizations of their nuclear forces. Still, analysts say that the Soviets have started to back down on this issue relatively early in the negotiating game.
According to this view, the Soviets know perfectly well that the US cannot accept limits on either forward-based systems or allies' nuclear forces. Thus, the thinking goes, the softening of the Soviets' positions in those areas means that their obligatory opening posturing is over, and serious negotiations may soon begin.
``It's very significant -- they've given these points away earlier this time,'' says Paul Warnke, one of the principal SALT II negotiators.
The Soviets have also backed off somewhat on their previous demand that sea-launched cruise missiles be banned -- a position the US will not agree to.
The powerful force that is driving negotiating positions on both sides, however, remains President Reagan's Strategic Defense Initiative (SDI). The central question of the current negotiations, many US analysts say, is whether the US and USSR can find a level of strategic defense research that is agreeable to them both.
The Soviet Union in the past has called for a ban on all work on what it has termed ``space strike weapons,'' while hinting that, in fact, it would allow some laboratory research. In his June 16 proposals, Gorbachev said the USSR would agree to SDI laboratory research, if the US would promise to abide by the 1972 antiballistic missile treaty for 15 more years, and to define more specifically what defense research the ABM Treaty prohibits.
Defense Secretary Caspar W. Weinberger insists that he, personally, would never agree to this position, claiming it would define SDI out of existence.
SDI critics say that the program is so long-term anyway that confining it to labs for a decade or so would not set it back much. ``You could have your cake and eat it too if you were clever about designing the test program,'' says John Pike, an analyst with the Federation of American Scientists.