WEEKS BEFORE the Soviet invasion of Afghanistan and the internal exiling of physicist and Nobel Peace Prize winner Andrei Sakharov, Valentin Turchin, an exiled Russian dissident who is now a professor of computer science in New York, proposed that the United States boycott the Scientific Forum that opens Monday in Hamburg, West Germany.

This is a meeting of scientific delegations representing the signatory nations of the Helsinki Accords, primarily for the purpose of discussing ways and means to promote scientific exchange and cooperation under that agreement. Dr. Turchin's argument was that it should be "morally impossible" for this country to participate when so many prominent Soviet scientists -- Yuri Orlov, Anatoly Scharansky and others -- are imprisoned for the crime of trying to monitor how their country is living up to the commitments made in the accords: to observe basic human rights, to allow free movement within and across borders and to foster the free flow of ideas. His argument was compelling then and is even more so now.

The semi-official U.S. delegation to Hamburg will be led by Dr. Philip Handler, president of the National Academy of Sciences. Despite having "precious little hope that what we have to say will be acknowledged by those who have so long demonstrated their unwillingness to listen," Dr. Handler believes that the forum offers a rare and valuable opportunity for scientists to express their concerns with Soviet policy in "face-to-face" confrontation." In a recent debate between the two men on the "MacNeil/Lehrer Report," Dr. Turchin responded: "The only way to get it through to the Soviets is to make something practical . . . one more expression of concern, one more protest doesn't make any difference."

What seems to be at the core of Dr. Handler's position, and that of many of his collegues, is a deeply held and treasured feeling among scientists that science is a uniquely international activity and one that should be held as far as possible "above" politics. He concedes that "knowledge is non-political . . . only as long as we make it so," and he knows -- none better -- that scientific cooperation between this country and the Soviet Union is an intensely political activity, in which scientists regularly put up with behavior (withholding data, censoring journals, sending party hacks to international conferences in place of distinguished invited scientists) that is anathema to them as scientists. Nevertheless, he argues that "it is in our national interest and the interest of humanity to adhere to the convention that science is international. I cannot believe there is any long-term benefit to reducing scientific behavior to simplistic political action and reaction."

There is a confusion here between science and politics, and the Hamberg meeting is, as Dr. Handler has admitted, really about politics -- the science is only incidental. In Dr. Turchin's words: "I think if the Olympic Games happened to be in Montreal nobody would think of if as sort of a vindication or justification or legitimization of their political system. But for the Soviet Union it is so, and what is applicable and is applied to Olympic boycott is exactly applicable to the scientific forum in Hamburg."

It is too late now to make Dr. Turchin's point or to use the Hamburg meeting as a lever to force the release from prison of dissidents Orlov and Scharansky, both of whom are reported to be seriously ill. If the meeting is to take place, then the U.S. delegation should approach it for what it is, and strive to forcefully make a few important moral points: that persecution of scientists for their political beliefs is unacceptable, that censoring journals is unacceptable, that forbidding all but a few of their scientists to attend international meetings is unacceptable. It is the very least they can do.