Something significant is happening in the United States. The American public is beginning to register its concern about the unrelenting nuclear arms race. The nuclear teach-ins on 151 campuses across the United States this week - involving thousands of students and faculty members - is the first such widely organized effort to bring popular pressure to bear on government policy. Whether this will grow into an enduring national movement is not clear. But it is clear that, with seminars taking place in 42 states and joined by military officers, politicians, clergymen, businessmen, the phenomenon is not something the Reagan administration can ignore.
The teach-ins are all the more significant coming as they do against the background of rising concern in other parts of the world as well. In Western Europe the antinuclear, antiwar movement has already made its weight felt. In Eastern Europe, too, governments are experiencing a public backlash to the huge Soviet military presence. In East Germany, Lutheran church organizations have been speaking out against ''militarization'' of the country and expanded military training of children. Romania, long a maverick within the Soviet bloc, has called for a reduction of European long-range nuclear weapons by both NATO and the Warsaw Pact.
Fitting these various strands into a single mold would be misleading. But there seems no escaping the broad conclusion that anti-nuclearism is putting down deeper roots. People everywhere, East and West, are genuinely anxious about humanity's accumulation of more and more atomic bombs and an apparent lack of will to reverse course.
It would be a mistake, too, to see the US seminars as a mirror image of the anti-Vietnam-war teach-ins of the 1960s. Or as reflective of a pacifist trend. Insofar as we can determine, these were not emotional peace demonstrations but level-headed, serious educational debates. The Union of Concerned Scientists, which sponsored the project, sought to avoid rekindling a confrontational mood and to make the arguments for arms control acceptable to political moderates.
It cannot be ruled out, however, that as future public meetings are planned - by a group called Ground Zero next April, for example - pacifist elements might begin to give the movement an extremist character. That indeed would be unfortunate. Supporting the control of nuclear weapons should not be confused with advocating unilateral disarmament or with reluctance to maintain an adequate defense in the face of Soviet military expansion. If they are to have an impact, future community teach-ins will therefore need to continue appealing to Americans in the center and right of center.
What direction this phenomenon takes will depend, of course, on the reaction from the Reagan administration. Disparaging the teach-ins as the work of unilateral disarmers and fellow-travelers would be foolhardy. Showing due sensitivity to public opinion, on the other hand, would prove useful in establishing a dialogue between government and people rather than feeding confrontation.
In this connection it is puzzling why President Reagan continues to agitate European opinion (and opinion at home) by his public comments on nuclear war. In his press conference the other day he reiterated the view that a tactical nuclear exchange in Europe is possible without igniting an all-out strategic war. In fairness, this is not inconsistent with NATO planning for the past 14 years. But surely there is a way to avoid creating the false impression that the US seeks to contain a nuclear war in Europe and thereby providing grist for the Soviet propaganda mill.
In terms of winning hearts and minds, the less said about ''limited nuclear war'' the better. The more said about the danger of resorting to nuclear weapons at all and about the possibilities for arms control the better. As it is, the administration seems to be working against its own objective of negotiating ''from a position of strength'' (how is this possible with European opinion so divided?) and getting the Russians to reduce the big missiles they have aimed at Western Europe. Mr. Brezhnev, it need hardly be added, is conducting a sophisticated peace campaign cleverly using lines fed by the President (although we would not dismiss a genuine Soviet interest in averting nuclear war).
The question, in the final analysis, is how long it will be before the superpowers pull back from what can only be termed an insane arms buildup. The United States now has close to 10,000 warheads. The USSR's arsenal is nearing 8 ,000. These are the grim facts which Americans of every age and walk of life are waking up to - and starting to protest. Will someone be listening