The surprise selection of a Polish cardinal, Karol Wojtyla, as pope of the Roman Catholic Church is a political statement of great importance in Eastern Europe and brings an unpredictable new dimension to East-West relations.

American diplomats familiar with the new pope and the temporal setting from which he comes received the news with fascination and, in several cases, elation about the possibilities inherent in the unexpected choice.

"My impression of him is of a great pastor who has an enormous appeal to people, a well-developed intellectual, a man of great force and with a shrewd political sense," said Richard T. Davies, who was U.S. ambassador to Poland from 1972 until February and who had many contacts and several lengthy conversations with Wojtyla.

Another former U.S. diplomat with extensive experience in the area, who asked not to be quoted by name, said the selection of the pope from a nation under Communist rule for 30 years could bring "a new leader to the Vatican who understands the Communists" and who may be "strongly opposed to attempts to expand their influence."

The selection of Wojtyla is expected to be greeted with special pride and tugs of attachment and association among the millions of Roman Catholics of Eastern Europe, a region of great strategic importance and political sensitivity lying between the Soviet Union and the West.

According to church publications, Eastern Europe's Roman Catholic population includes 31 million Poles (some 92 percent of the entire population), 11 million Czechoslovaks (75 percent), 6 million Hungarians (60 percent), 1.6 million East Germans (10 percent), and 1.1 million Romanians (6 percent).There are lesser numbers of Roman Caltholics in Albania and Bulgaria.

In addition, some 3 million Soviet citizens of Lithuanian orign are listed as Roman Catholics in church publications.

Choice of the Polish Cardinal reminded some observers of the sensational fictional reign of Kiril Lakota, the Ukranian priest selected as pontiff in Morris L. West's 1963 best-selling novel, "The Shoes of the Fisherman." The fictional Kiril acted as a secret intermediary between the Soviet premier previously his interrogator and torturer, and the American president in an effort to avert nuclear war.

Even though such international intrigue as the novel offered is highly unlikely, there is little doubt that the unusual background of the new pope was being studied with great intensity in the Kremlin, as it was in the White House, State Department and other centers of temporal power in the United States.

As a symbolic statement by the church of the importance and vibrancy of Catholicism in Eastern Europe, the selection of Wojtyla will have an impact that will be carefully watched by political leaders everywhere. This may be short-lived, but experts here cited several reasons why the elevation of this man, with an expectation of a lengthy reign, may have major longterm significance.

First, the new pope's practical experience in operating the church in a nation under Communist rule is believed to have given him great skill and sophistication in the political arts.

One could hardly be successful, as he has been, in this delicate situation without acquiring an acute sense of timing and finesse in maintaining integrity and independence in an adversary situation.

Second, his experience may give him special qualifications in dealing-with the "Eurocommunist" parties of Italy and other nations in the west.

There was speculation at the State Department that this may have been among the reasons for his selection, in view of the dilemmas facing the church in Italy.John Paul II, as outsider without local ties to political factions, may be less restrained by previous connections than his Italian colleagues in dealing with that situation.

As a bellwether of spiritual strengrh in the face of polical travail, the Polish pope is already a powerful symbol to the church and its followers in authoritarian of totalitarian countries throughout the world. If he chooses to do so, John Paul II as churchcraft may give new meaning to that old question, How many divisions has the pope?"