Why Soviets toughen anti-US line cautiously

The Kremlin has promised its apparently impatient military more and better weaponry, but still would like a negotiated exit from a full-scale arms race with the Reagan administration.

And while Soviet leaders have suddenly toughened their public tone toward Washington, they still appear leery of getting carried away, lest this undercut popular pressure for nuclear arms control in the West.

This, at least, is the strategy suggested by a pair of top-level Soviet policy statements within the past week, portrayed as something of a mid-course correction in relations with President Reagan. The first speech came Oct. 27 from Soviet President Leonid Brezhnev in a rare televised meeting with top generals and admirals. The second came two days later from Konstantin Chernenko, a Politburo member and longtime Brezhnev aide.

Together, the statements suggested a delicate Kremlin bid to vent growing anger and frustration over Reagan administration policy, but in a way that might balance concessions to contradictory political and economic pressures at home.

On the one hand, senior Soviet officials have long suggested in private remarks a perceived Kremlin need to remind President Reagan that the Soviet Union is a superpower. (Mr. Chernenko, in his speech, went so far as to single out for criticism ''almost two years (of) abusive language'' from the US administration toward Moscow.)

Published statements in recent months suggest that the Soviet military, in particular, feels the Kremlin has spent too much time trying to propagandize Mr. Reagan into changing his stripes, and not enough time or resources on beefing up the armed forces.

Earlier this year, the nation's top career military man, chief of staff Nikolai Ogarkov, wrote of the special need constantly to upgrade weaponry in an age ''when the basic scientific progress in weapons systems is renewed every 10 to 12 years.'' He also implied that problems in the Soviet civilian economy had disturbing implications for the military.

But one abiding problem for Kremlin decisionmakers is that even in a Soviet socialist economy - if not particularly in such a system - guns necessarily compete with butter.

Mr. Brezhnev's message to the military was that, in light of two years of tension with Mr. Reagan, the generals and admirals would get, indeed must get, requisite support in hiking ''combat readiness'' and keeping pace with world weapons technology.

In an oddly defensive remark, the Soviet leader also assured the top brass he kept ''constantly'' abreast of military affairs.

Yet he also stressed throughout the ultimate policymaking prerogative of civilian leaders, in the shape of the Soviet Communist Party, and in effect reminded the uniformed elite, that arms were costly things.

''The party Central Committee adopts measures to meet all your needs,'' Mr. Brezhnev declared. ''And the armed forces must always be worthy of this concern.''

At least partly in deference to the military audience, one presumes, Mr. Brezhnev had included a pledge not to ''abandon'' international detente, but omitted reference to arms control talks with the Americans as part of that process.

Mr. Chernenko, in his follow-up speech, echoed the Soviet leader's toughened overall tone toward the US, and at one point seemed to suggest the Kremlin had decided simply to write off chances for improved relations with the Reagan administration. ''The US ruling class has not stood the test of detente, the test of peaceful cooperation,'' he said.

But the main thrust of the speech was quite different. The Soviet Union, Mr. Chernenko said, was determined not to react rashly to what he termed Washington's ''bellicose . . . and boundlessly egocentric'' policies.

Although Mr. Chernenko said Moscow was ''sufficiently strong and can wait'' if current US attitudes prevail, he also said:

''The Soviet Union is opposed to a further growth of tension in Soviet-American relations. We stand for their normalization and improvement, and are prepared to engage in businesslike and detailed negotiations which must, of necessity, take into account the interests of both sides. . . .

''We believe that sooner or later - and the earlier, the better - reason will triumph. . . .''

One day later, a communique capping Soviet-Finnish talks here explicitly expressed hope for ''constructive agreements'' from current US-Soviet talks on nuclear-arms limitation.

The assumption of many foreign analysts here, meanwhile, is that the precise weight of arms negotiation versus arms production in Soviet policy, or of tough rhetoric versus conciliatory calls for revived East-West detente, may have yet to be finally calibrated.

With senior Soviet officials not immediately commenting on the implications of the Brezhnev and Chernenko addresses, diplomats suggest the first reliable signals will likely come behind the closed doors of arms-negotiating chambers in Geneva, or perhaps in the address traditionally delivered by a Politburo member in early November as part of celebrations of the anniversary of the Russian Revolution.