London — At the heart of the latest diplomatic maneuvering over nuclear weapons is an escalating, three-sided struggle to sway European public opinion throughout 1983 and beyond.
Immediately at stake: how Western Europe is to defend itself against Soviet intermediate-range missiles aimed at its cities, and whether the Soviets can be persuaded to reduce those missiles significantly.
Essentially at issue are two broader, fundamental perceptions. One is of morality - are nuclear weapons moral or immoral? The other is of the Kremlin itself - does it genuinely want peace, or is it trying to hoodwink the West with deceptive propaganda offers of missile reductions?
On the three sides of the struggle for the mind of Western Europe are the Soviets, the Americans, and the growing peace protest movement across Europe. The movement's leaders now see new opportunities to block NATO intermediate-range missiles from Europe altogether.
The latest Soviet effort to influence Europe against NATO intermediate-range missiles (cruise and Pershing) is the Yuri Andropov offer Dec. 21. The Kremlin leader suggested that Moscow would reduce its missile strength to the level of British and French missiles if the US abandoned plans to install 572 cruise and Pershing II missiles in Europe.
The latest US effort to rally the NATO alliance behind the cruise and Pershing plan was Secretary of State George Shultz's delicate tour of European capitals earlier this month.
Throwing its weight against the Reagan administration is the peace movement, headed in Britain by the Campaign for Nuclear Disarmament and coordinated in Europe by the European Nuclear Disarmament movement, known as END for short.
Interviewed here immediately after the Andropov offer had been made, leaders of both groups welcomed it.
They stressed their confidence that they had an ''excellent chance'' now of blocking cruise and Pershing missiles altogether. Both groups plan a series of demonstrations around Europe throughout next year culminating in what they call a ''hot autumn'' - large demonstrations in a dozen or more cities bringing together left-wing politicians of all kinds, church groups, trade unions, young people, environmental groups, women, and others.
The Soviet view, evidently, is that the US can be persuaded at least to reduce the number of cruises and Pershings it deploys. Strategic experts here think a likely compromise is that both Moscow and Washington will eventually agree to equal numbers of intermediate-range missiles. That way, neither side will give them up altogether, even though the US plan calls for zero missiles on each side.
The view of the US and of such NATO allies as Britain is that only NATO determination to deploy cruise and Pershing has forced the latest Andropov offer. Now is the time to stand firm, the reasoning goes, to see what else the Soviets might be prepared to offer.
The view of the peace movement is that all nuclear missiles are immoral, and that both Moscow and Washington should be prepared to cooperate and reduce them as much as possible.
Meanwhile, peace movement leaders welcome the Andropov offer. ''Yes, I think he means it,'' commented Msgr. Bruce Kent, general secretary of CND, in an interview after a press conference in London Dec. 21.
''If he wants to save his own skin, and his own family, then reducing nuclear weapons is the only way . . . . We should respond constructively. We should say, 'Fine, and now we will cut our missiles to some level. . . .' We should all make cuts. . . .''
Mary Kaldor, editor of END - Journal of European Nuclear Disarmament, said, ''I think it is a perfectly serious offer. . . . Quite a major offer. . . . The problem so far is that neither side has taken the offers of the other side seriously. . . . We don't think reductions should be balanced.
''The Andropov offer is likely to be rejected by the US, but. . . .''
Both Msgr. Kent and Mary Kaldor were buoyant at peace protest activities around Europe in recent months. They pointed to:
* The widely-publicized demonstration by 20,000 to 30,000 women at Greenham Common, northwest of London, Dec. 12-13, against the installation of 96 cruise missiles at a US military base there.
* A Gallup poll in October that interviewed about 1,200 people around Britain and reported 58 percent opposed to cruise missiles and 56 percent opposed to Britain's independent nuclear deterrent, the submarine-launched Trident missile. Among women the figures were 64 and 60 percent respectively.
* Agreement by peace groups in Britain, Sweden, Holland, Spain, Belgium, West Germany, and Italy to stage demonstrations throughout next year.
* Demonstrations at US bases in West Germany.
* The decision of the Danish Parliament to refuse to contribute toward the NATO costs of installing cruise and Pershing missiles, and Norwegian approval by only a single vote.
* The number of local government councils in Britain declaring themselves to be nuclear-free zones is now up to about 140.
* CND's so-called ''peace canvas,'' in which it claims that at least 100,000 activists will knock on ''every front door in Britain'' to solicit opposition to all nuclear weapons here.
Among plans for 1983 are a series of antinuclear rallies at Easter and in the fall, and the second European nuclear disarmament convention in Berlin in May.