POPE JOHN PAUL II spoke with extraordinary force when he called for an end to the violence in Northern Ireland. It is hard to think of a more perilous exercise in peacemaking than one concerning that ancient feud. The pope addressed it in words that were skillful, direct and moving.

"Violence is a lie," he said, "for it goes against the truth of our faith, the truth of our humanity." The people who plant bombs for the IRA consider themselves the champions of a Catholic Ireland, and they had been looking to the pope for a few words that, with a little twisting, might have been represented as indicating a degree of tolerance of their activities. Perhaps that expectation seems crazy, but the IRA lives in a twilight world of misperceptions and warped mythologies. The pope knew what the IRA was looking for, and categorically denied it to them. He kept repeating, explicitly, that there were no exceptions to the precept: "Nobody may ever call murder by any other name but murder." That declaration was immensely heartening to those Irish Catholics, in both public life and private, who have been carrying on the struggle against terrorism.

But there was more to his message. In condemning the IRA's methods, he recognized that their movement is nourished by the injustices that persist among Ulster's Catholic minority. He urged Irish politicians to seek peaceful reconciliation and to resist "conditions which give excuse or pretext to men of violence." To the British authorities running the police forces and jails in Northern Ireland, where the IRA's violence has sometimes been met with official violence, the pope offered a reminder that the need to preserve order does not justify violations of human rights. To the Protestant majority in Northern Ireland, which fears that Irish unification would mean Catholic oppression, he offered brotherhood. "Every community," he said, "has rights which must be respected."

In terms of conventional politics, the most important work of the pope's long trip may have been done on his first stop. In Ireland, after all, the IRA is deliberately attempting to instigate a civil war. But perhaps in the pope's own view the dangers to which he intends to speak in the United States are only less obvious than those besetting Ireland. In Ireland he had a number of things to say about a culture devoted to the breakneck pursuit of wealth, at great cost to families and communities, but to the benefit of the traffic in drugs. To a great many Europeans, the United States is the source and leading exponent of that culture. To a man who has spent much of his life working in the austere circumstances of the Catholic Church in Poland, the extravagances of American life must be astonishing. In Ireland, Pope John Paul II made it clear that he intends to speak forthrightly to the moral questions that he sees about him. He will undoubtedly address Americans as he did the Irish-- with great warmth, but unambiguously.