Pope's visit means 3 White House firsts

But they disagree over the war in Iraq, just as Bush did with Benedict's predecessor, John Paul.

When Benedict was a cardinal before the 2003 invasion, the now-pontiff categorically dismissed the idea that a preventive strike against Iraq could be justified under Catholic doctrine. In his Easter message last year, Benedict said "nothing positive comes from Iraq."

Benedict told Bush at their first meeting last summer at the Vatican that he was concerned about "the worrisome situation in Iraq." Bush characterized the pontiff's concerns as mostly limited to the treatment of the Christian minority in Muslim-majority Iraq. The statement out of the Vatican suggested a broader discussion.

Weigel predicted talks this time would be focused almost entirely there.

Prominent Christians have been slain in Iraq in recent weeks and tens of thousands of Iraqi Christians are believed to have fled the country because of attacks and threats. "The Vatican is a very adult place," he said. "The arguments of five years ago are over."

The current pope's approach may be softer than that of John Paul, who turned from Bush's presentation to him of the Medal of Freedom in 2004 to read a statement about his "grave concern" over events in Iraq. But Benedict is no less committed to the church's stand on issues such as abortion, stem cells and the death penalty, as well as war.

In fact, the death penalty is another area of long-held disagreement, with Bush a strong supporter. Benedict also speaks forcefully against punitive immigration laws and the U.S. trade embargo against Cuba, and for environmental protection and social welfare _ all in ways that often run counter to Bush administration policies.

Clinton clashed, too
But differences between popes and presidents are nothing new.

John Paul and former President Clinton clashed — with strikingly sharp Vatican statements — on abortion.

Also, the church's opposition to almost any war but self-defensive ones has been a persistent theme in U.S. relations.

Pope Paul VI wanted to help mediate an end to the Vietnam War. John Paul also urged President Reagan against the arms race and spoke out vigorously against the Persian Gulf war under the current president's father. All these urgings, like the current anti-Iraq argument, were to no avail.

"Modern popes have seen themselves as voices of conscience and peacemakers," Allen said. "U.S. administrations haven't always been excited for them to play that role."

Weighty discussions aside, the talks with Bush are not likely to be the most-remembered or most influential part of the pontiff's six-day, two-city U.S. tour, Weigel said. That is expected to come when Benedict addresses the United Nations on Friday.

"I think it's nice they're going to meet. They have a lot of things to talk about," he said. "But the notion that the world operates by the big guys getting together and cutting a deal is wrong."

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