In a recent speech before the National Association of Evangelicals, President Reagan described our confrontation with the Soviet Union in terms of moral absolutes: ''the struggle between right and wrong, good and evil.''
This is undoubtedly the way the President and many in this country see the contest with America's principal adversary. Whatever one may feel about the justice of America's cause, the speech raises serious questions regarding the appropriateness of such statements to our international relations.
Many who admire the United States for its freedom and for its democracy would still take issue with our assertions of ''rightness'' and ''goodness.'' Such assertions risk shifting the area of debate - particulary abroad. The issue becomes not the relative correctness of US policies but the moral rectitude of the United States. Is that not for others to decide and apply?
The President who spoke of the ''temptation of pride'' in another context might have applied it to this as well. He might also have recalled another biblical verse: ''He that is without sin among you, let him first cast a stone . . ..''
Moral absolutes complicate diplomacy. Our ability to work with the nonaligned countries of the world was not helped over the years by their recollection of John Foster Dulles's statement that nonalignment was ''immoral.'' Diplomacy is the adjustment of often opposite interests among nations. As President Kennedy wisely showed at the time of the Cuban missile crisis, diplomacy succeeds when there are no winners or losers.
Americans have a hard time accepting the practice of diplomacy exactly because they tend to see international relations in absolute terms. Many add, as the President has done, the moral factor. The acceptance of any agreement negotiated with an adversary is complicated by the feeling that it is a compromise with ''evil.''
If the true objective of the administration is to reach a verifiable and effective arms control agreement with the Soviet Union, this type of characterization of America's principal adversary is not likely to help toward that objective. Whatever we may think of our adversary, the USSR is a proud and serious country with strong perceptions of its national interest and its own sensitivities. We do not need to placate it or praise it, but we need to approach it on a businesslike basis if our diplomacy is to succeed. The President's approach is not likely to make that task any easier.
Setting an issue in the context of moral absolutes also risks the polarization of US domestic debate. This approach tends to move the national discussion of the details of an arms control policy away from legitimate differences over the content of that policy to the preservation of ''our freedom'' and ''our belief in God.'' Phrases such as ''simple-minded appeasement or wishful thinking about our adversaries'' place moral judgments upon sincere advocates of different policies. That is not a formula for constructive discussion within the country of one of the most serious issues of our time.
Our nation, further, has in international forums been the strongest opponent of applying moral rhetoric to the debate on other issues. We have long opposed those in the third world or in Africa who would see any relationships with South Africa in terms of the ''evil'' of the apartheid system. We have strongly resisted the efforts of some to put Middle East issues in terms of moral judgments. We have insisted, in both cases, that factors on both sides needed to be taken into account; that moral judgments were not a constructive approach to solutions.
President Reagan has a tendency to believe that he can shape his approaches on foreign policy to the audience he is addressing. This is a luxury no president can enjoy. Any speech a senior US official makes on foreign policy is a speech to all aduiences. When a president speaks in extreme terms and when most of the world assumes that this is how he really feels, other more temperate expressions of policy will have little effect.
Whether this is Reagan's basic intention or not, he signals to the Soviets and to our allies in Europe his implacable hostility to our principal adversary. He cannot then wonder why the Europeans and many in the United States doubt the sincerity of his approach to arms negotiations. To say in his speech, as he did, that ''I intend to do everything I can to persuade them (the Soviets) of our peaceful intent'' is hardly likely to be effedtive when, in the same speech, he refers to them as ''the focus of evil in the modern world.''
To reject this appreach to diplomacy is not to take issue with the virtues of American society or with the serious denigrations of human rights and dignity that are part of the Soviet system. It is to suggest that in a period when we are dealing with a new leadership in the Soviet Union and with restless allies in Europe stating our diplomatic posture in terms of moral absolutes is dangerous. It clouds the specific issues of the debate and makes the acceptance of nego-tiated agreements more difficult.
In the US, the presidential speech is one of the primary instruments of diplomacy. In most administrations, it is an instrument that has been sparingly used and carefully placed in a broad context of diplomatic and policy objectives. Whatever the circumstances of a speech in which US relations with the Soviet Union are mentioned, that speech is a part of our basic negotiations with that country and a part of our global effort to win other nations to our point of view.
Moral absolutes intended, perhaps, to appeal to a particular audience become a fundamental part of this nation's diplomatic message. If that is the intention of the administration, it should be with a full realization of the consequences of this approach to world issues.