ROME – It’s rare indeed when an American president takes part in a four-way conversation and was, arguably, the least remarkable person in the group, but such was the case in June 1975 when President Gerald Ford made a visit to the Vatican.

On that occasion, Ford met Pope Paul VI, today St. Paul VI, the pope who guided the Catholic Church through the close of the Second Vatican Council and the immediate post-Vatican II years. The two were joined by then-Archbishop Agostino Casaroli, the legendary Vatican diplomat who authored the Holy See’s policy of Ostpolitik, or outreach to the Soviet bloc.

At the time, Casaroli was playing a key role in negotiations that would lead to the Helsinki Accords, an agreement that brought together all the European states, East and West, as well as the U.S. and Canada, and which has been cited repeatedly by Pope Francis and his aides as a template for multilateral engagement.

The other party to the conversation was Henry Kissinger, at the time still the U.S. Secretary of State as well as the National Security Advisor, and perhaps the most celebrated, and controversial, statesman of the 20th century.

Based on a now-declassified memorandum about that 1975 conversation, we know it was wide-ranging: The Middle East, including negotiations at the time toward an agreement between Egypt and Israel on the Sinai; Lebanon and its swelling population of Palestinian refugees; the Helsinki process (including Ford’s warning that western Europe should not “capitulate and give in to Russia”); Vietnam, including the settlement of refugees in the U.S.; the Portuguese revolution, and U.S. fears that a Communist-backed government in Lisbon could unravel the NATO alliance; the future of post-Franco Spain; not to mention Ethiopia, Malta and Cyprus.

It was not the first time Kissinger, who died Nov. 29 at the robust age of 100, had swapped views with his Vatican counterparts. According to the transcript, Paul VI actually referred to Kissinger as an “old friend,” noting that the two had met on at least two previous occasions.

Nor was Casaroli the only opposite number in the Vatican with whom Kissinger had contact.

As part of the Wikileaks releases, for instance, we know of an October 1973 conversation between Kissinger and then-Archbishop Giovanni Benelli, at the time the sostituto, or “substitute,” of the Secretariat of State, in which the two discussed the recent coup in Chile that brought down the government of Salvador Allende.

According to the cable, Benelli advised Kissinger to ignore reports of massacres and abuses by the forces of General Augusto Pinochet, describing those claims as “Communist propaganda.”

That bit of history is a reminder that while Kissinger is best known for having the ear of presidents, over the course of his remarkable career he was also often a counselor to popes as well.

His first meeting with Pope John Paul II came during a private audience in October 1979, after Kissinger no longer had any official role in the American government, and it didn’t occur under the most propitious of circumstances.

Chilean Foreign Minister Hernan Cubillos would later recall that a year earlier, just after then-Cardinal Karol Wojtyla had been elected to the papacy, he met Kissinger at his Manhattan residence at the River Club, whereupon Kissinger delivered himself of the opinion that the choice of a Polish pope was a deliberate provocation to Moscow and might not be “good for humanity.”

Nevertheless, John Paul II and Kissinger hit it off, and would continue to interact often during the next quarter-century. In 2001, for example, Kissinger brought his wife Nancy to the Vatican to receive a blessing from John Paul, and when the pope died in 2005, Kissinger told NBC he was convinced that John Paul II, not him, was the most influential figure of the 20th century.

Whenever Kissinger was asked by interviewers about John Paul II, he would always say that he was so attached to the pope that he had saved the photos of every meeting they ever had.

Kissinger also had entrée with John Paul’s successor, Pope Benedict XVI, who met the legendary American diplomat during a lengthy audience at Castelgandolfo in September 2006.

The chemistry between the German pontiff and the Germa-born Kissinger was sufficiently strong that one Italian newspaper reported afterwards that Benedict had asked Kissinger to serve on an unofficial council of foreign policy advisors, a rumor the Vatican subsequently was compelled to deny.

One year later, Kissinger would be back in Rome to address the Pontifical Academy of Social Sciences, saying: “For somebody who has had the honor of having audiences with three Popes and to have respected and admired the role of the Church over the centuries, to be able to be in the Vatican with a group dedicated to these purposes means a great deal.”

In fact, Kissinger was a regular on the Roman scene, in part as a result of his close friendship with Gianni Agnelli, the longtime head of FIAT and a fixture on the Italian political scene for decades. Gore Vidal, in his 1995 memoirs Palimpsest, recalls bumping into Kissinger during a 1994 dinner sponsored by Agnelli in the Hall of Statues at the Vatican Museums, to celebrate the restoration of the Sistine Chapel.

“As I left him gazing thoughtfully at the hell section of The Last Judgment,” Vidal wrote of Kissinger, in typically caustic fashion, “I said to the lady with me, ‘Look, he’s apartment hunting.’”

Over the years, Kissinger and the popes with whom he forged relations certainly had their differences, especially during the Paul VI/Casaroli era and the questions of how best to navigate the challenges of the Cold War.

On the other hand, Kissinger clearly admired the Vatican’s capacity to take the long view of international relations. Despite being associated with an approach of Realpolitik, which critics would say was based more on cynicism than high ideals, Kissinger also seemed to appreciate the unique sense of the transcendent the Vatican strives to bring to very earthly questions.

“The German philosopher, Emmanuel Kant, wrote an essay in the eighteenth century, in which he said someday there will be universal peace. The only issue is whether it will come about by human insight or by catastrophes of such a magnitude that we have no choice,” Kissinger told that meeting of the Pontifical Academy of Social Sciences in 2007.

“He was right then, and he is right today, although some of us may add that it may take some divine guidance and not just insight to solve the problem,” he said.