THE scene was the Old Executive Office Building in Washington. The audience, Nixon officials, were listening uncomfortably as a scientist made the case that dealing with environmental threats required substantial planning; in fact, he argued, climatic change operated on a 22-year cycle. Why wasn't the government paying attention? ''You don't understand,'' said an official. ''In Washington, we operate on two-, four-, and six-year cycles.''
Since Richard Nixon left office, that point has been demonstrated repeatedly by White House occupants. We have had a succession of short- and one-term presidents, accompanied by rapid changes of public mood, and it has become fashionable to bewail the difficulty of framing even moderate-range policy - especially foreign policy - to manage the nation's business.
The reelection of Ronald Reagan offers the first eight-year administration since Dwight David Eisenhower. For the first time in many years we have the possibility of establishing continuity in United States foreign relations.
But the reelection of the President may obscure a more troubling truth: namely, that regardless of who's in the White House, our country seems to be falling into a pattern of two-year policy cycles.
The first two-year presidency was one in fact as well as policy. Gerald Ford responded admirably to the overwhelming public desire for honesty in government. But lacking a mandate, Ford found it impossible to carve out a secure niche for himself as chief executive. After 21/2 years he was gone, and in came Jimmy Carter.
Mr. Carter was the product of a confused, cautious, pessimistic, and even fearful public opinion. As observers from Carter speech writer James Fallows to Brandeis professer Seyom Brown have noted, the new President had no more coherent vision than those who elected him of where he wanted to lead the United States. His belief in ''fifty things but no one thing'' provided the mental context for two successive foreign policies.
From 1977 through the end of 1978, Jimmy Carter No. 1 offered a kind of diffuse ''world order'' policy, pushing human rights, cultivating influential regional powers in the third world, reducing US commitments overseas, and looking the other way in the face of Soviet or Soviet-backed adventurism.
In the winter of 1978-79 two events kicked off a dramatic shift of emphasis among the President's colliding world views. The Shah fell from power in Iran, and Vietnam attacked Cambodia. Public opinion had already begun to shift in the direction of higher defense spending and a tougher attitude toward the Soviets, and Carter now began to listen more to the hard-line views of his national security adviser, Zbigniew Brzezinski, and less to those of his conciliatory secretary of state, Cyrus Vance.
From 1979 through 1980, the result was Jimmy Carter No. 2, a President who raised the defense budget, expanded US commitments in the Gulf and the Far East, compromised on human rights and on his earlier effort to cut US arms transfers abroad, and reacted strongly to the Soviet invasion of Afghanistan. It was of course too late for the public, which had formed its opinions of Carter during the first policy cycle. Reagan campaigned against Carter No. 1 and won.
However one views him, there is no question that President Reagan came to the White House with a clear vision of where he wanted to lead America, as well as with skills of management and communication his predecessor lacked. But curiously, his administration has also shown signs of the two-year policy cycle.
In the Middle East, for example, the administration originally asked Arabs and Israelis to join a ''strategic consensus'' against the Soviets, despite age-old antagonisms which to them were more important than the Soviet threat. But two years ago it altered its focus by presenting a program to deal with the Arab-Israeli dispute. In the Far East, it considered a closer relationship with little Taiwan in the face of objections from a real makeweight in the global balance of power, China. Subsequently, Reagan continued and improved relations with the People's Republic of China (PRC). In Central America, it first threatened what could be viewed as a radical policy of ''going to the source,'' but in the past two years the administration has pursued a balanced policy.
What does all this mean for the two-year cycle in foreign policy? Can we expect more of what are in effect two-year presidencies?
Despite the historical variety sketched above, three factors do appear to stand out as largely responsible for the two-year cycle. First, there is the tendency of every aspirant for the White House to couch his campaign in terms of opposition to everything his opponent stands for, and then to act on his campaign positions once he gets in office. Second, there is the education of each new administration as it attempts to translate its preconceived ideas (whether confused, ideological, or just abstract) into action in an unforgiving ''real'' world. Third, there is public opinion, which may reverse signals on an administration in midterm as it did for Jimmy Carter.
Whether these conditions will persist to plague US foreign policy is of course an open question. It does seem they will be mitigated by the reelection of an incumbent president. And yet all three factors also seem inevitable byproducts of the interaction of human nature, democratic processes, and a volatile world. It will take courage and discipline on all our parts to overcome them.