WASHINGTON -- Two decades after the U.S. Catholic bishops issued their landmark pastoral on peace in a nuclear age, its theological foundation stands but its policy arguments based on superpower conflict have become virtually irrelevant in a post-Cold War world haunted by terrorism and brutal ethnic warfare, according to a panel of experts from a wide variety of political perspectives.

They spoke at a workshop for bishops, a day before they open their regular meeting here. The panel included the Rev. J. Bryan Hehir, one of the architects of the pastoral letter, "The Challenge of Peace," and one of its fiercest critics, conservative lay theologian Michael Novak.

The letter, which was closely associated with the late Cardinal Joseph Bernardin of Chicago, was founded on the writings of Vatican II and of Pope John XXIII, which reaffirmed Catholic "just war theory" in the modern age and created a place for the idea of conscientious objection, said Hehir, principal staff member to the committee that drafted it. Just war theory specifies certain conditions under which warfare can be considered morally legitimate.

Politically, the letter was set in a time when opposing superpowers each possessed enough nuclear weapons to destroy the world. Its main argument, which Hehir still believes was right for that time, was that nuclear deterrence, rather than unilateral disarmament, had to be accepted as a temporary solution until mutual disarmament could be achieved. That strategic part of the letter, which attracted enormous political and news media attention, "is really a period piece" today, Hehir said.

A third part of the letter that focused on how to create the conditions for peace was not well developed, and is the part of the letter that might be further built upon today, he said.

The moderator of the panel, Archbishop Diarmuid Martin, coadjutor of Dublin, Ireland, and a former representative of the Vatican to international institutions based in Geneva, kept the panelists on their toes by asking counterintuitive questions. While Hehir was asked to assess the letter's weaknesses, Novak was asked to assess its strengths.

Novak praised the bishops for opening up the drafting process to public debate, saying he found the final draft much better than the first. It did a great deal to make just war theory the centerpiece of national debate about the morality of war, he said.

"It was a great thing to see the bishops address the world from a religious framework" regarding an issue that many people didn't view as religious, he said.

Novak said the greatest weakness of both "The Challenge of Peace" and the Vatican and papal documents it drew on, however, was a failure to seriously consider the deep sinfulness of human nature, which makes some wars inevitable. Novak had defended the U.S. invasion of Iraq, which both the bishops and the pope criticized.

At the same time, Novak said, the letter didn't put enough emphasis on the importance of working politically to change key leaders in a nation in ways that will make its culture more supportive of democracy and human rights. A former U.S. ambassador to the United Nations in the 1980s, Novak confessed that he had paid little attention to human rights concerns in places such as the Middle East, and that that neglect led to dire consequences.

"We are beginning to set a new vision for the Middle East. There is no reason why the people of that region, blessed with so many natural resources, should live in such dire poverty" under the rule of tyrants, he said.

Sister Mary Evelyn Jegen, while representing a very different political perspective than Novak, also sounded themes of sin, repentance and conversion. A former U.S. coordinator and international vice president of Pax Christi, a Catholic peace-making organization, she noted that it was founded during World War II by a French Catholic who was appalled that French and German Catholics could attend the same Mass and then kill each other.

"What moves the movement is a sense of [contradiction] in celebrating the Eucharist and then feeling that there is a legitimate way to kill those for whom Jesus died," she said.

Archbishop Edwin O'Brien of the Military Archdiocese, considered a rising star in the U.S. hierarchy, praised the role of the U.S. military in preserving world peace, but said his chaplains stand ready to aid any soldier who has moral objections to any individual military operation.

"If he is sincere, the priest will do his best to help him through and get a hearing," O'Brien said. Because civil law does not recognize "selective conscientious objection" to some, but not all, wars, however, there is a strong possibility that such a soldier will spend time in jail, he said.