The Hague — Mient Jan Faber, a giant of a man, is a spellbinder before an audience. He is the secretary-general of the nuclear pacifist Interchurch Peace Council (IKV) - and, quite a few Dutchmen think, a future leader of the Labor Party.
In a conversation in a cluttered IKV headquarters at Anna Paulowna Square, he considers why the Dutch peace movement has had the greatest political impact within its country of the European peace movements:
''It has something to do with the way we more or less succeed in combining moral issues and practical issues. . . . Many ordinary people judge the problems in particular in moral terms. They can take part in our campaign because their approach is seen [by us] as very valuable.
''But on the other hand, we also try to bring together parliamentarians, to hold [policy] discussions in the ministries and confront (officials) with what is going on on the popular level. So we have a fairly steady, ongoing way of trying to close the gap between what ordinary people say and their emotions and . . . strategic discussions.''
Mr. Faber continues: ''That has something to do with the kind of organization we are. We are in the middle of the church. We are in the middle of society. We have links with [officials].''
Despite these links, will the center-right government succeed next summer in its efforts to get parliamentary approval of initial preparations for new missile deployments in the Netherlands in 1986?
''You could say we have a 50 percent chance of stopping it,'' replies Nico van Arkel, a draft-age conscientious objector who is doing his alternative service at IKV. ''But even if they decide to deploy in June of next year, factual deployment is only in 1986 in the Netherlands. But just before that we have elections, in which the antimissile Labor Party is now expected to gain seats. The electoral process might thus still reject the missiles.''
The Netherlands is the one deploying country that might go back on the unanimous 1979 NATO decision to station new Euromissiles in the mid-'80s.
If the Netherlands reneges, the primary credit for the policy switch will have to go to IKV. The Dutch peace movement has had far more impact on public opinion than any of its fellow organizations in Western Europe, and it is far better integrated into existing institutions - the churches, trade unions, and political parties.
This has enabled IKV to block successive governments from pinning down parliamentary approval for the planned cruise missiles. Should the Labor Party again inherit the government in Holland's shifting coalitions, this absence of a final ''yes'' would become a final ''no.''
IKV's considerable influence results from several specifically Dutch factors, including a strong moral (or moralistic) tradition in public policy, the homogeneity of a small country, a left-leaning postwar consensus, the multiplicity of Dutch political parties, and a postwar democratization of foreign policy that has brought security decisions into the public marketplace.
When IKV turned from third-world concerns to stress nuclear pacifism in the late 1970s, it found the Dutch political system quite responsive.
The worldly Atlantic coast traders and bankers - who had rebounded from the shock of Hitler's violation of Dutch neutrality in World War II to become the most ardent postwar supporters of the NATO alliance - might have been aghast at what they regarded as the naive unilateralism of the peace demonstrators.
But the Interchurch Peace Council linked Protestant and Roman Catholic churches in social issues. Once the church hierarchies endorsed nuclear pacifism , it wasn't long before the trade unions did, too. Wim Kok, leader of the larger of the Dutch trade union federations, spoke at the first big antinuclear demonstration in 1981 as a private person. In the most recent demonstration a month and a half ago, he spoke on behalf of his unions.
Support for the IKV slogan - ''Free the world of nuclear weapons and let it begin with the Netherlands'' - has not gone that far among Dutch parties. But the Labor Party officially opposes the new NATO missiles. And growing opposition among Christian Democrats has made successive Christian Democratic prime ministers wary about ever bringing the missile issue to a vote.
The Netherlands thus provides a touchstone to judge the political success of peace movements in other NATO countries. In every case, the movements' influence on institutions - and through institutions on politics and policy - is much weaker.
In the religious world, neither the Protestant nor the Roman Catholic hierarchies of Britain or West Germany have embraced nuclear pacifism. Official church statements on nuclear issues in Britain, West Germany, and France, have generally expressedmoral anguish about weapons of mass destruction - while tolerating nuclear deterrence as a necessary evil for the time being.
The exception has been the Reformed Protestant churches of West Germany, which have rejected nuclear deterrence as immoral.
As for the labor movement, British and West German trade unions have been more concerned about unemployment than new missiles. Outside the Netherlands the peace movement remains largely an ideal of the young educated middle class. It has not spread upward very fast to the governing elite - or downward to the workers.
Among parties, the British Labour Party calls for unilateral British nuclear disarmament - and got trounced in the June election. The West German Social Democratic Party finally shifted to reject new NATO missiles last November - some months after it had lost 6 percent of workers' votes in the Ruhr Social Democratic heartland as it began moving to the left.
In contrast, the ruling French and Italian Socialists have been impatient with peace movement demands. The French party staunchly supports both the French force de frappem and the new NATO Euromissiles. And the Italian Socialist prime minister is proceeding with the Italian cruise deployments with no qualms.
In West Germany the appearance of the Greens, a protest party that won seats in the Bundestag for the first time last March, could be interpreted either as a legitimization of the debate about nuclear pacifism or as rejection of the political system and parties by the antinuclear environmentalist youth counterculture.
Except in the Netherlands the policy influence of the antimissile opposition parties is nil.