Soviet troops are now manning missile launching sites in East Germany. The Soviets say the move was taken reluctantly and only in response to a military buildup by the West.
Western analysts, however, suggest that the Soviets would have taken the move anyway, and are merely adding to a formidable arsenal that already has most of Western Europe under threat.
The deployment is yet another benchmark in the continuing dispute over nuclear weaponry in Europe. If the missiles are armed with nuclear warheads, it could well be the first time the Soviet Union has placed intermediate-range nuclear weapons outside its own territory.
The timing of the announcement was ''certainly deliberate,'' says a Western embassy source. It coincided with the meeting of Soviet Foreign Minister Andrei Gromyko and US Secretary of State George Shultz in Stockholm.
The Soviets, the source says, want to make it clear that their threatened countermeasures to US-supplied NATO missiles in Western Europe are proceeding apace.
That would seem to fit hand in glove with the tough stance enunciated by Mr. Gromyko at the conference on European disarmament in Stockholm. In a speech to assembled foreign ministers, he said: ''The deployment of new US missiles that has begun in certain West European countries does not contribute to international security or to the security of the countries which have taken the risk of such deployment.''
Confirmation that a Soviet missile unit is in East Germany came in the Soviet Army newspaper, Red Star. Although the report did not specify where in East Germany the missile sites are, or what kind of missiles were deployed, Western embassy sources speculate that the Red Army unit controls one or more SS-22 missiles, presumably armed with nuclear warheads.
The Soviet leadership has repeatedly warned that it would place Western Europe and the US under a threat equal to the one the USSR faces from the new NATO weapons. And Soviet leaders have said they will return to negotiations on intermediate-range nuclear missiles in Europe only if the new NATO missiles are removed.
NATO government spokesmen have flatly rejected that precondition, arguing that the Soviet Union already has a significant edge in the European nuclear balance.
Presumably, the new Soviet missiles could themselves become the subject of any future negotiations.
Western military analysts say the new SS-22 missiles are replacements for an earlier generation of SS-12 missiles. The missiles have a range of about 600 miles and could presumably hit most targets in Western Europe. The missiles can deliver up to 500 kilotons of explosive power, or about 33 times as much as the Hiroshima bomb.
The Soviet Union has also threatened to deploy missiles in Czechoslovakia.