On the eve of the resumption of Soviet-American arms talks in Geneva, it has become apparent here that the 108 Pershing II missiles that West Germany has agreed to accommodate from the end of this year are the crucial issue on the negotiating table.

The Soviets are saying privately that however much they dislike the idea, they may eventually be able to live with the slow-moving cruise missile. But they are emphatic in their insistence that Moscow could not accept the deployment of the Pershings.

Pershing II, they insist, is a strategic first-strike weapon capable of destroying virtually all Soviet command and control points throughout European Russia. A movement toward their actual deployment would force Moscow to revise its calculations for the strategic arms talks in Geneva and possibly break them off altogether, by this account.

Publicly, Moscow maintains that both Pershing II and cruise missiles are strategic weapons whose deployment in Western Europe would constitute a "most serious threat to peace." Yet the Soviets, who have deployed medium-range nuclear weapons on their European flank, seem resigned to some new American counterparts resulting from NATO's deployment decision.

The Soviets have gone out of their way to convey to various European leaders their concern about Pershing IIs in particular. Their deployment, they argue, would cut down warning time to six minutes.

In pursuing its policy, Moscow is employing a classic double strategy. On the one hand, its propaganda and diplomatic efforts are tailored to exploit deep divisions within Western European electorates on the question of nuclear weapons. On the other, it has demonstrated some flexibility on several key points to keep the doors open for a possible agreement with the United States.

Moscow's diplomatic and propaganda efforts include a combination of veiled threats and intimations of possible concessions. Soviet leader Yuri Andropov's offer to sharply reduce the number of Soviet medium-range missiles to that of the total of French and British nuclear weapons is a part of this.

Soviet officials say privately that Andropov's offer could be taken as Moscow's "starting" position if the Reagan administration is interested in serious talks at Geneva. It was made, one source put it, to generate "some motion" in the talks.

Simultaneously with various peace offers and arms control proposals, Moscow is projecting implicit and explicit threats apparently designed to convey the seriousness of Soviet concern. There is speculation here that the Soviets may place some nuclear weapons in East Germany and another Warsaw Pact country if the NATO deployment plans proceed on schedule. The move would have little strategic significance, but it could produce new tensions in Western Europe and West Germany in particular.

Moscow has made plain that it is considering a switch to a policy of "launch on warning," or an automatic response to the first sign of any attack, to counter the threat posed by Pershings. Moreover, Andropov has announced recently that the Soviets have tested a long-range cruise missile, presumably a weapon similar to the U.S. long-range cruise, which could be deployed on submarines near the United States.

Despite threats and warnings, it seems clear that Moscow wants to come to an accommodation with Washington. In the course of the flurry of peace initiatives, the Soviets have proposed cuts of medium-range weapons, indicated that they are prepared to dismantle some of their SS20 medium-range missiles aimed at Europe and stated readiness to broaden verification procedures to include some form of on-site inspection of missile stations.

These changes in the Soviet position have opened the possibility of an agreement in Geneva under which NATO could deploy some U.S. cruise missiles while the Soviets would be prepared to make a substantial cut in their force of SS20s.

As seen from here, the crucial issue is still that of the Pershing IIs. The armed forces chiefs are said to be unequivocally opposed to any deal that would include their deployment in West Germany.

Moscow moved quickly last week to quash speculation about a possible "intermediate solution" advanced by West German Foreign Minister Hans-Dietrich Genscher. In doing so, the Soviets did not rule out the possibility of an intermediate solution but rather the one offered by Genscher--deployment of some Pershing IIs and cruise missiles, not all 572, in exchange for a cut in the Soviet medium-range force.

Although the Soviets are acknowledged masters of the art of bluffing, they seem intent on being taken seriously on the Pershings.

It is said here that this concern provides an opportunity to Paul Nitze, the chief U.S. negotiator in Geneva, to push down the proposed Soviet ceiling of 162 SS20s--based on the current French-British total--if he is given a mandate to do so in the early part of this year.

The main thrust of Soviet propaganda is that Moscow does not want to pay the price of another round in the arms race, that it is prepared for an agreement based on "equality and equal security" but will not shrink from matching the United States if a missiles race is imposed on it.