Mikhail Gorbachev's call for the ``urgent'' negotiation of a separate agreement on medium-range nuclear missiles follows private assertions by Soviet officials that they have not abandoned hope of a comprehensive arms control agreement with the Reagan administration. The latest Soviet initiative came Saturday, just two days after the country resumed nuclear tests - a display of strength, probably aimed at a domestic audience, which may have been intended to balance off this new concession.
By breaking up its own package of arms control proposals, which it had previously termed ``indivisible,'' Moscow is apparently hoping to achieve a number of objectives: give new impetus to disarmament talks with the United States, improve its image in Western Europe, and push forward talks on the balance of conventional forces in Europe.
During the Reykjavik, Iceland, summit last October, Soviet leader Gorbachev offered major concessions on medium-range missiles, but insisted that they could only be concluded within the framework of a comprehensive disarmament package. This would include limitations on the development of President Reagan's Strategic Defense Initiative (SDI, or ``star wars''). Negotiations foundered on this point.
Gorbachev's latest statement seems to repeat these concessions.
At Reykjavik, Gorbachev agreed that each side should reduce the total number of warheads for its medium-range missiles to 100 within the space of five years. All US and Soviet medium-range missiles would be removed from Europe: the US warheads to the US, the Soviet warheads to the Asian part of the Soviet Union.
In essence, Gorbachev was accepting US terms for an agreement.
Moreover, shortly before Reykjavik, the Soviets dropped their demand that British and French missiles be included in negotiations.
On Saturday, Gorbachev also explicitly stated that, once agreement on medium-range missiles was reached, Moscow would withdraw its short-range missiles from East Germany and Czechoslovakia. This will simultaneously please the missiles' reluctant hosts and the West Germans, against whom the missiles were targeted.
The US claims Moscow has deployed a total of 441 modern SS-20 missiles, each with three independently targetable warheads, plus a further 112 20-year-old SS-4 medium-range missiles, each with a single warhead. Moscow admits to 373 such missiles (including 243 SS-20s) in the European part of the Soviet Union.
Gorbachev's reference in Saturday's statement to ``our common European home'' made it clear that the announcement was directed as much at Europe as at Washington.
Moscow has been encouraged by the support recently voiced in Western Europe - particularly West Germany - for the traditional interpretation of the 1972 Anti-Ballistic Missile Treaty.
Washington is currently arguing a broader interpretation. The West Germans initially expressed disappointment at the failure of the Reykjavik talks on medium-range missiles.
But after Reykjavik, a number of Western European governments expressed concern that the removal of the US nuclear cover in Europe will leave them at a strategic disadvantage. Moscow may now do its best to induce NATO to join in discussions for comprehensive reductions of conventional forces in Europe.