The way things have shaped up this year strongly suggests that the summit of 1989 may well be a meeting between ideological leaders of two worlds - Christian and Marxist. It is an intriguing possibility that would have been unthinkable only a few years ago. Communist leaders have called at the Vatican from Nikita Khrushchev's time on. But their visits were largely protocol and achieved nothing of substance.
Today's circumstances are vastly different. It is difficult to visualize an encounter of such opposite outlooks more dramatic and more fraught with potential than one between Pope John Paul II and Soviet leader Mikhail Gorbachev.
The two are key figures in a new era of international relations in which, apart from superpower involvement, the churches in the communist states and mankind at large have an abiding interest.
A whole series of developments - including striking concessions to religious activity in the Soviet Union and Hungary - now seem to make such a meeting a certainty next year. It would have a profound impact on church life throughout the communist world.
The scenario began unfolding early this year when the Soviet leader told the Italian newspaper Unita of his lively interest in an already projected official visit to Italy. Unquestionably it would also mean a meeting with the Pope.
The Pontiff himself wished to go to the Soviet Union for this year's millennial celebrations of the advent of Christianity to Kievan-Rus' - the historic name of what is now the Ukraine - in the year 988.
That wish foundered on Soviet political sensitivities about the Pope's ideas of itinerary and on Vatican fears about how Moscow could capitalize on his presence on Soviet soil.
Instead, therefore, John Paul made it a ``spiritual'' pilgrimage, as he said in a letter addressed to Ukrainian Catholics, in which he also called on Moscow to restore the church banned by Soviet leader Joseph Stalin for the free exercise of their faith.
The Catholic clerics who did make the September trip included Jozef Cardinal Glemp, primate of Poland and head of not only the biggest Catholic congregation in the East bloc, but also the one most likely to influence new Kremlin thinking about church-state relations.
That thinking first emerged in an April 29 meeting between Gorbachev and the head of the Russian Orthodox Church, Patriarch Pimen, who was assured that perestroika (restructuring) and the democratization of Soviet society applied also to the church.
Believers, he was told, had a ``full right to practice their religion.'' It was a simple enough statement but a profound reversal of previous Soviet attitudes.
He also conceded the right of the church to concern itself with modern social problems, a remarkable admission not lost on East Europeans, particularly the Poles, with whom the question has been a point of confrontation with the communist authorities ever since the war.
A new attitude on the place of the church in society, Gorbachev said, was essential to ``national unity'' in what he called a period of change.
Cynics might be excused for recalling that Stalin also invoked that unity in 1943 when he needed the church's support for the war effort and allowed many of the churches he shut down to reopen. Tolerance, however, lasted only as long as the war.
Western human rights groups point out that, under Gorbachev, some 200 believers are still in prison or labor camps for violations of state restrictions governing all religious activity. ``There is much that he can do right away to prove his good faith,'' a Western Roman Catholic cleric observes.
Without doubt, Gorbachev's apparent promise of a new dispensation for Soviet believers is motivated by his need to stimulate more active popular support for his reforms. Nonetheless, an unusual tolerance is already evident, for example, in the Baltic states, especially in predominately Roman Catholic Lithuania. And whatever the Soviet leader does within his own country is felt in the East bloc.
Reactions to church demands for more freedom vary greatly within the East bloc. Reform itself is still an un-word in Romania. East Germany and Czechoslovakia tell Gorbachev they have their own ideas on the subject. Poland and Hungary are his only strong perestroika allies.
Not surprisingly, the same breakdown applies in religion. East Germany has been cracking down strongly on Evangelical demands for ``change and renewal.'' Czechoslovakia and Romania continue to provide the bloc's worst record of harassment of believers and their churches.
In Poland, however, there seems finally some break-through in the church's persistent struggle since the early 1970s to persuade the Warsaw government to give back the constitutionally corporate status it enjoyed before the war.
Last month, the government reportedly offered the church legal guarantees for public activities such as publishing, youth activity, etc., in return for full diplomatic recognition by the holy see.
Hungary is even closer to a concordat on recognition. Recently, the Vatican was able to appoint two archbishops and two bishops without prior approval of the Budapest government. Elsewhere in the East bloc - apart from Poland - such approval is still obligatory, with priestly ``socialist patriotism'' still governing criterian. 5 After his September trip to the Soviet Union, Cardinal Glemp talked of ``a new start'' toward reconciliation between the two churches and their two nations. That - at this writing - is shadowed by the Polish government's delay with the promised ``round table'' with the opposition.
But the more Gorbachev carries out his new approach to believers, the greater the pressure on Poland's Gen. Wojciech Jaruzelski to show equal realism in accommodation with his own Roman Catholic church.
The Pope has three times visited his Polish homeland. But direct talks are now under way to line up a Papal visit to Hungary next year.
That and a Gorbachev call at the Vatican would be an immense boost for all the beleaguered faithful elsewhere in Eastern Europe.