IT SEEMS MORE than 11 years ago that President Nixon and Henry Kissinger went to Moscow to formalize the first Soviet-American agreements that gave us the era of "detente." Then, in the spring of 1972, the '70s were expected to be years of growing cooperation, stability and predictability.

Many harsh lessons later, the emotive meaning of the term "detente" in the United States is quite different. So is the state of Soviet-American relations. Today, after more than two years of the Reagan administration, and with a new leader in the Kremlin, we have no clear plans for how to pursue relations with the Soviet Union.

So where do we go from here? The conventional way to answer that question is in terms of the three classical "alternatives" -- detente, containment or confrontation. But positing these as alternatives is an oversimplification. I would like to argue that an intelligent American and Western alliance policy toward the Soviet Union in the '80s would combine all three, without relying too heavily on any one of them.

In an era of increasingly powerful and accurate nuclear weapons and a continuous arms race, the danger to both the East and West has increased dramatically; so has their need for managing and regulating their conflict and their cooperation. This is probably the first time in history that alliances divided by such sharp differences have shown so much interest in conflict management and cooperation. This change in attitude is one product of the nuclear revolution in international affairs.

In a world of strategic parity and mutual assured destruction, detente between West and East in one form or another is simply unavoidable. The scope, intensity and forms of a detente relationship between East and West may differ in particular periods. But because both the Soviet Union and the Western nations want to avoid a highly dangerous runaway arms race and unstable and unpredictable conflict, and because both are drawn to at least limited cooperation in the areas where their interests overlap, some form of detente is unavoidable in the remaining decades of the 20th century.

The goals of the Western alliance are not limited to the avoidance of nuclear war -- which of course does have the highest priority both for the Soviet Union and the allies. As well, the United States and its allies are anxious to prevent Soviet global expansionism, insure the survival of independent and democratic systems in the West and promote orderly and evolutionary change in the Third World.

The Western powers face a serious dilemma in this regard: how are they to frustrate Soviet expansionism while simultaneously minimizing the chances of a nuclear escalation? Some form of detente makes the conflict with the Soviet Union more stable and therefore less dangerous. But this is only useful if, at the same time, the Soviet Union remains relatively contained. Without a determined and successful policy of containment, neither our world nor our values will survive.

We will only succeed in containing Soviet power when the costs and risks to the Soviet Union of the kind of international behavior they engaged in from 1975 to 1979 increases substantially. Under the umbrella of nuclear parity, the Soviet Union is determined to exploit targets of opportunity in the Third World. We may be certain that in the disorder and turmoil that we must expect in the '80s in many parts of the Third World, the Soviet Union will be repeatedly tempted to improve its global power position through direct and indirect military means.

The Western alliance, and particularly the United States, will have to declare its vital interests outside Europe, and prepare a credible response to Soviet expansion whenever it encroaches on those interests.

For this response to be credible and therefore effective, the United States and Western Europe have to be ready for a political, economic and military confrontation with the Soviet Union or its satellites. The global, although selective, containment of Soviet power can be achieved only if the threat of West-East confrontation is credible.

So detente, containment and confrontation are not mutually exclusive policies. They can and will coexist; the mixture of the three will depend on the state of opinion inside the alliance and particularly inside the United States as much as it depends on Soviet behavior.

To the end of this century and probably beyond, democratic nations will have to face the conflict with the Soviet Union and also strive for cooperation with the Soviet Union. In effect, we have to wait out the expansionist stage of Soviet development, without being able to predict how long it may last. While we wait we will need to practice detente, containment and confrontation -- and we will need good sense and good luck, too.