Popular peace movements can be a two-edged plowshare. The longing for peace is putting pressure on Moscow as well as the West. To a degree, the Kremlin is experiencing its own peace backlash.
This is the message that the East German Lutherans and the Romanian Communist Party chief are sending the Kremlin these days. Even the errant Soviet submarine in Sweden's waters has stirred an unexpected wave of anti-Soviet feeling.
Moscow's concern about all this may help to explain the conspicuous failure of Soviet-bloc citizens to give indirect support to the West European antinuclear movement by mounting their own 1950s-style mass peace rallies in East Europe and the Soviet Union.
The same concern also surfaced recently when a leading Soviet marshal expressed anxiety about the desire of Soviet youth for peace at almost any price.
In East Germany five of the eight regional Lutheran church organizations held synods in the past few days in which peace was the main theme. Speaker after speaker at the synods objected to increasing ''militarization'' in East Germany and expanding military training of children. They condemned education that brands fellow human beings as enemies.
They asked that conscientious objectors to military service be given a choice of alternative civilian duty (a right that in West Germany is written into the Constitution). One report to the synod in Saxony objected specifically to the training of 11-year-olds in the use of hand grenades.
So sensitive is the whole issue that East German authorities barred West German journalists from attending the synods.
Romanian leader Nicolae Ceausescu has weighed in on a similar subject in recent weeks with two public calls for a reduction of European long-range nuclear weapons by both East and West.
What particularly galls the Russians in this, diplomatic observers say, is Ceausescu's equation of a dismantling of existing Soviet SS-20 missiles with retraction of the NATO decision to deploy new missiles two to seven years hence. The West regards its planned new weapons as a response to already-deployed Soviet weapons (as does Ceausescu, by implication). Moscow maintains, however, that the new NATO weapons would be a new spurt in the arms race.
In Sweden, the violation of restricted territorial waters of a neutral neighbor by a sub apparently carrying nuclear arms has also led to some peace backlash against the Soviet Union. Some Swedish opponents of the planned new NATO nuclear missiles have enlarged their protests to address them to Moscow as well as Washington.
And the Moscow-blessed popular movement for a Nordic zone free of nuclear weapons might conceivably now turn its indignation on the existing Soviet nuclear presence in the Baltic ''sea of peace'' as well as on the potential wartime American presence.
Criticism of Soviet as well as American shoves to the arms race has been evident in the various antinuclear marches in West Germany. Many Social Democrats in particular have made a clear protest against excessive Soviet as well as excessive American armament a condition of their participation.
The impact is unequal, of course, since the demonstrations exert substantial political pressure on the Bonn government not to carry out NATO plans while exerting no political pressure at all on the Soviet Union.
Nonetheless, the Russians must be keeping a wary eye on that element of the West German antinuclear movement that is alarmed by Soviet as well as NATO nuclear buildups.
In the Soviet Union itself there is no question of any grass-roots challenge to defense policies arising comparable to the antinuclear movement in Western Europe. But even in that closed society the 1970s decade of detente - and the concomitant fading of the image of America and West Germany as archfiends - may have weakened public willingness to be mobilized.
Such a concern, at least, was voiced by Marshal N. Ogarkov, Soviet first deputy defense minister and chief of the general staff, in an authoritative article in the Communist Party journal Kommunist last July.
''Over a period of 36 peaceful years two new generations of people have in fact grown up having no knowledge derived from personal experience of what war is. They have the idea that peace is the normal state of society,'' noted Ogarkov.
And he complained, ''Questions of the struggle for peace are sometimes interpreted not from class positions, but somewhat simplistically; any kind of peace is good, any kind of war is bad. And this could lead to unconcern, smugness, and complacency, and to underestimating the threat of a possible war.''
Concern about the potential spillover from Western European peace movements into Eastern Europe or even the Soviet Union may not restrain Soviet support of antinuclear movements in Western Europe very much. But Western intelligence claims of extensive Soviet manipulation of the movements has yet to be proved.