WASHINGTON -- As the son of Cuban immigrants, Miguel Diaz was drawn to Barack Obama for his ability to cross cultures and engage people from different backgrounds.

Now, plucked from the relative obscurity of central Minnesota to be President Obama's envoy to the Vatican, the St. John's University theologian finds himself in the vortex of an unwelcome battle over what it means to be a Catholic in the service of a president who supports abortion rights.

All sides say the debate was inevitable, no matter whom Obama sent to the Holy See. But for Diaz, the swirling debate seems as confining as the white tie and tails he wore last month for his first audience with Pope Benedict, a theological conservative determined to return the church to traditional Catholic values.

"As a person of faith, I am stunned by any effort that seeks to divide us," Diaz said in a phone interview from Rome with the Star Tribune. "One of the things I have embraced from this presidency is the effort to bring various persons together to engage in conversations even when we disagree."

To the extent that anybody outside the church had ever heard of Diaz, the 46-year-old professor from Collegeville, Minn., is identified with a left-of-center theology that emphasizes human rights and social justice.

That's disconcerting for conservative Catholics, who see opposition to abortion as a central moral tenet of the church. When Diaz presented his credentials as the new U.S. ambassador last month, Pope Benedict asserted the "need for a clear discernment with regard to issues touching the protection of human dignity and respect for the inalienable right to life from the moment of conception to natural death ... The Church insists on the unbreakable link between an ethics of life and every other aspect of social ethics."

With just a month under his belt in Vatican City, Diaz -- the son of a Havana waiter and his seamstress wife -- seems to already have mastered the delicate art of diplomatic indirectness, an essential skill in the notoriously Byzantine politics of the Italian loggia.

Asked about reconciling the church's "pro-life" theology with Obama's "pro-choice" politics, Diaz -- fluent in English, Spanish, Italian and French -- suggested that a media interview is not the forum for straightforward ethical statements on abortion.

"In order for me to formulate what I would like to formulate, it would take me more than a simple answer," Diaz said. "So I resist categories of either/or, in terms of arguing this or that. Unfortunately, it does not allow me the time to be able to explain in a thorough and satisfactory way what I mean by whatever I would say I am," he said.

'Political hardball'

Despite that ambiguity, Diaz and the skeptics of his appointment may have found common ground on at least one point: He is in Rome to represent the Obama administration to the church, and not the other way around.

"I'm not here to be a theologian or a spokesperson for the Catholic Church or any other religious entity," he said.

Though Diaz has no clear public record on abortion, his appointment has been seen in some circles as an attempt to isolate Catholic conservatives in the United States by elevating a member of the church's liberal wing -- a representative of its burgeoning Hispanic flock, at that.

"It leads to the thought that this administration is prepared to play serious political hardball and get its way with a significant chunk of the Catholic vote," said Catholic theologian George Weigel, a senior fellow at the conservative Ethics and Public Policy Center.

To Weigel and other Obama critics, Diaz's appointment is of a piece with an earlier, controversial invitation for Obama to speak at Notre Dame, which deeply divided American Catholics.

"What would really be a dumb idea," Weigel said, "is if [the White House] imagined this to be another surrogate in an attempt to split the Catholic community in the United States. It's not a suspicion without ground."

Among those who share that suspicion is John Zuhlsdorf, a Catholic priest from Minneapolis who moderates a popular conservative Internet blog. Diaz's "appointment could be part of a larger campaign to suborn Catholics in the United States," said Zuhlsdorf, known to his followers as Father Z. "Obama doesn't care what the Catholic Church teaches. This is an aggressively pro-abortion politician. And everyone knows Catholics are a huge voting demographic."

Still, Diaz's appointment presents a dilemma for Obama's culturally conservative critics. Unlike some of the other rumored candidates -- including Caroline Kennedy, the daughter of former President John F. Kennedy -- Diaz comes with no culture-war baggage.

As the first Hispanic U.S. envoy in the 25-year history of diplomatic relations with the Vatican, Diaz also puts a face on the one-third of American Catholics who claim Hispanic heritage, a demographic that is increasingly important to the Vatican.

Together with his relatively low political profile, Diaz's immigrant background has tended to blunt -- if not eliminate -- Catholic criticism of Obama's pro-choice politics.

"In that sense, Obama short-circuited the potential for this nomination to be inflammatory," said John Allen Jr., who covers the Vatican for the National Catholic Reporter.

Another observer, Trinity College religion professor Mark Silk, calls it "an inspired choice to have someone who is a fresh face, sort of Obama's generation, part of a new generation of Cubans."

A matter of conscience

Some conservatives acknowledge that there's something benign about Diaz, who is best known for his work in Hispanic culture. "Obama had to find an ambassador to the Vatican," Zuhlsdorf said. "He wasn't going to pick someone who was a conservative Catholic."

Even so, Diaz's careful statements about inclusiveness and building bridges will do little to allay the concern of conservative Catholics that he was picked to legitimize the liberal idea that abortion is a matter of personal conscience.

"They've awakened something they might not want to awake," Zuhlsdorf said.

If so, it's a debate for which Diaz has shown very little appetite.

"I would rather spend my energy focusing on the multiple things we agree on," said Diaz, who presented the pope with a vase made in Minnesota by Richard Bresnahan, artist in residence at the College of St. Benedict and St. John's University.

Diaz, whose parents immigrated legally from Cuba when he was a child, said he's interested in working with the Vatican on shared interests such as combating HIV-AIDS, human trafficking and poverty.

"We relate to the Holy See as a sovereign entity, as a global humanitarian actor, and as a moral voice in the world," Diaz said.

Kevin Diaz • 202-408-2753