Cardinal Walter Kasper, head of the Vatican office that deals with other Christian churches, and Cardinal Ivan Dias, who oversees Catholic missionary work, will both address the Anglicans' Lambeth Conference, which opened Wednesday (July 16) in Canterbury.
The cardinals' presence underscores Rome's commitment to more than four decades of Anglican-Catholic dialogue aimed at restoring "full visible unity" between the two churches, separated since the 16th century.
But this year's Lambeth Conference takes place amid intense intra-Anglican turmoil that is complicating ecumenical dialogue with Rome and perhaps encouraging some Anglicans to leave and become Catholics.
The Anglican Communion is deeply divided by its Western branches' embrace of a gay Episcopal bishop in New Hampshire and same-sex unions in some parts of the U.S. and Canada.
The Vatican has long been sympathetic to the concerns of conservative Anglicans. In 2003, then-Cardinal Joseph Ratzinger, who is now Pope Benedict XVI, sent a friendly though noncommittal greeting to a gathering of U.S. conservative Episcopalians in Texas.
At the same time, the Vatican is troubled by recent moves within the Church of England--the mother church of the worldwide communion -- to allow women bishops. More than 1,300 Anglican priests have threatened to leave if that's allowed.
Yet the Vatican's ecumenical officials have nevertheless consistently discouraged an Anglican schism as antithetical to the ultimate goal of Christian unity.
"We are on good terms with the archbishop of Canterbury and as much as we can we are helping him to keep the Anglican community together," Kasper told a British interviewer last December.
Such support, however, in not unconditional. Kasper's office released a statement last week saying that the prospect of women bishops in the Church of England is a "further obstacle to reconciliation."
It is that prospect, and the refusal of the Church of England to allow a separate all-male hierarchy to accommodate traditionalists, that is fueling talk of a mass exodus from the Church of England to Rome.
Such a movement could also draw in Anglicans on the other side of the Atlantic.
"There is increased interest on the part of Anglo-Catholics in the States in coming into full communion with the See of Rome," said Bishop Jack L. Iker of Fort Worth, Texas, who said he has taken part in "very cordial and hopeful conversations" at the "highest levels" in the Vatican.
Although the traditionalist wing of Anglicanism is dominated by evangelicals, who emphasize their communion's roots in the Protestant Reformation, a significant minority is composed of Anglo-Catholics, whose worship and theology is strikingly close to Rome's.
Anglo-Catholic bishops attending Lambeth will be holding their own meetings on the side, Iker said, and he expects Lambeth to be a "clarifying moment."
"It may be that a number of them will come to the conclusion, if they haven't already, that the future is not within Anglicanism but in union with the pope," he said.
Iker's support for a collective migration to Rome, as distinct from a series of individual conversions, would depend on the establishment of an Anglican enclave within Catholicism on the model of the Eastern Rite Catholic Churches, which maintain separate hierarchies and distinct practices, including married priests.
"The celibacy thing continues to be of concern," Iker said.
That issue in particular could prove a decisive obstacle. Although the Vatican permits the re-ordination of previously married Anglican priests who convert, it has given no sign of flexibility on celibacy as the norm for Roman Catholic clergy.
"Popes have held onto (celibacy) in spite of many pressures," said Monsignor William H. Stetson, who has personally supervised the conversion of approximately 100 Episcopal priests since the early 1980s.
"To create a Western entity within the Catholic church with optional celibacy--I don't think there's any receptivity to that in Holy See."