People duck their heads and say that we and the Russians are headed back to the "cold War." But this is a careless and misleading use of the term. We need clearer beacons by which to navigate in the uncharted sea ahead.

Superficially, the Cold War meant nasty words, the rhetoric of confrontation and, beyond that, the sense of an anti-communist or anti-Soviet crusade on the American side and some mirroring Soviet sense of high-stakes global engagement.

I do not object to going back to a "Cold War climate" if it encourages straight talking, wariness and resolution in our self-interest. The cliches of detente were, finally, stultifying. But this time around we should be more aware of getting carried away. Cold War rhetoric is open-ended -- lots of accelerator, not much brake or steering wheel. It is not "just rhetoric," meaningless words.

The Cold War was essentially a harsh but limited political contest between the Soviet Union and the United States:

1) It had its sideshows, some of them big and bloody (the Korean War), but at bottom it was a struggle to reestablish a balance of power in one place, post-World War II Europe, by the two big powers on the edges.

2) It was fought throughout by means short of direct military conflict between the two main participants.

3) It had an end, or so many felt. The Cuban missile crisis of 1962, brought on by Nikita Khrushchev's eagerness to force a solution to the Berlin question, resulted in what many Westerners at least saw as a mutual readiness to explore peaceable ways, signified by the partial nuclear test ban, the Berlin agreement and much else in the name of detente.

This time, however, the limits are less certain:

1) The main Soviet purpose seems to be not the partially defensive one of establishing a new balance centering in Europe but the entirely offensive one of testing the possibilities for expanding Soviet power in regions beyond the wildest imperial fantasies of the czar.

2) So far, at least, though the Soviets have shown no taste for a direct engagement with American power, they have proved themselves ready to send a proxy's forces and now their own outside the bloc.

3) Whether the stage we're in now will have an "end" we can't tell.

But the real difference may turn out to lie in the strategic context. The panic and vulnerability we felt after World War II seem irrational as we recall that we had a nuclear monopoly during the earliest Cold War years and vast nuclear superiority through the whole period, not to speak of a continuing conventional-weapons edge and an incomparably superior economic plant and reach. We had the resources for a global struggle and, notwithstanding our fears, no serious reason to worry about a Russian reaction. The Kremlin understood this better than we did and, after swallowing East Europe, tended to conduct a conservative policy as a result.

That security cushion is gone. The Kremlin did not begin to acquire resources, especially military resources, on anything approaching the American scale until in optimists' eyes the Cold War was over. Now, though its economic reach remains limited, in military terms it has drawn abreast and stimulated widespread anxiety about it future intentions.

Under the influence of Khrushchev's latter-day reachings for detente, I hoped that the Soviets would not necessarily come to translate the military power they were plainly accumulating into unilateral geopolitical advantage. I am now much more dubious that the Soviet leadership can resist such temptation -- unless checked.

The significance of the Afghanistan operation lies precisely in its showing, to all but the willfully blind, that having the horses does make a difference. In this sense, Moscow has perhaps reestablished an American foreign policy consensus that has not existed since the Cold War. The first big mistake of the 1980s may be Leonid Brezhnev's.

The Cold War finally came down to the feeling that the fates of the two societies would and should be decided apart from each other. It was this go-it-aloneness, perceived as a necessity and a virtue alike, that created its characteristic mood of the expectation of conflict and war, and invited excesses in the name of national security.

It would be unforgivable to let ourselves again be overtaken by the illusion that we can lead a decent national life without some measure of collaboraton with our Soviet rivals. Vigilance is an overriding American interest, but so is civility. The task of policy is to find the right balance.