When the 38 leaders of the 70 million-member worldwide Anglican Communion gather this week in London to discuss how to handle the recalcitrant Episcopal Church USA and its views on sexuality, the result could be a fundamental change in the American church.

The emergency two-day meeting at centuries-old Lambeth Palace was called in response to the Episcopal Church's decision this summer to confirm an openly gay priest as bishop and to allow dioceses the option of performing liturgical blessings for same-sex relationships.

While the primates, or archbishops, meet regularly to discuss a variety of issues, a meeting such as this on a single topic, with the future of the 2.3 million-member Episcopal Church in the balance, is unprecedented.

It will be a gathering rife with subplots and behind-the-scenes meetings, of new alliances and old grudges, of the financial strength and longtime power of the American and British provinces vs. the numerical superiority and growing influence of the African, Asian, and Latin and South American provinces, the so-called "global South" that adheres closely to biblical tradition.

"It really is a very historic moment," said the Rev. Arnold Klukas, former rector of a Pittsburgh Episcopal church and now a professor of liturgical theology at Nashotah House seminary in Wisconsin. "It's going to be a major turning point for good or ill.

"This is the first time that what holds the Anglican Communion together has been tested. Can the church chastise a member and bring them into line with the rest of the church? If they can't, the whole question of what the Anglican Communion is is up for grabs."

Some primates from Africa and Asia have publicly called for the Episcopal Church to be denied membership in the Anglican Communion; in essence, being demoted to an observer status with no say in church affairs.

American conservatives want a realignment of the Episcopal Church, one that would recognize the right of bishops to extend their oversight across current diocesan borders to like-minded conservatives in liberal dioceses.

The Anglican Communion has no central, authoritative government, and participation in the communion is by invitation. Primates' meetings are described as non-legislative, collegial gatherings that serve as conversations about common issues throughout the church.

But there are precedents for direct intervention by the archbishop of Canterbury, the spiritual head of the Anglican Communion who among the primates is considered "first among equals." Both instances occurred during situations of war and destruction in the 1980s and 1990s in the Sudan and Rwanda.

Although the meetings will be private, their possible outcomes have been the subject of much discussion.

In ascending order of severity, observers say the communion could:

Do nothing. This is considered unlikely because it means that the Rev. V. Gene Robinson, the gay bishop, would be consecrated on schedule next month without any unified comment from church leadership.

Issue a conciliatory letter seeking agreement within the communion.

Establish a commission to study the issue. This was done in 1988 when the Eames Commission examined the issue of ordination of women. Even before the six-year study concluded that various provinces should try and maintain "the highest level of communion possible" given their disagreement over the issue, women already were being ordained as bishops.

Censure, or rebuke, the Episcopal Church. Such an action -- probably in the form of an official letter -- would have little concrete effect and be more of a rhetorical display.

Reduce the Episcopal Church to observer status, disallowing it from participating in matters of Anglican governance. Some observers say this would unfairly penalize the denomination's conservative members, who have argued that Robinson's confirmation abrogates biblical authority and centuries of church teaching.

Create a new church in North America unbound by geographic contiguity. In this scenario, both the Episcopal Church and the new province would be in communion with the worldwide church, each with its own jurisdictions and presiding bishops.

Suspend the Episcopal Church and the supporters of Robinson from the Anglican Communion, and establish a new church in America whose practice lies within the limits of Anglican diversity.

It's also possible that Robinson would voluntarily withdraw, but few believe he would throw away the years of work by progressive elements of the church that led to his election as bishop of New Hampshire and subsequent confirmation at the General Convention.

The meeting could produce a demand that the Episcopal Church's Presiding Bishop Frank T. Griswold not consecrate Robinson next month and prescribe potential punishments if he disregarded that.

Or some African and Asian primates could separate their provinces from the Episcopal Church by declaring their provinces out of communion with the American church.

This week's meeting shares some parallels with the 1998 Lambeth Conference, the once-a-decade gathering of Anglican bishops in Canterbury. Oftentimes at these, highly influential decisions are reached, even though they are advisory in nature and nonbinding.

At that conference, by a 526-70 vote with 45 abstentions, bishops voted that homosexual practice is "incompatible with Scripture."

The vote was doubly important as it showcased the influential role African and Asian bishops played in the discussion. Though adhering to Bible-based church teachings anyway, they were mentored by conservative Episcopal bishops, the result being a powerful conservative voice within the Anglican Communion. In the five years since, the global South's influence in the church has grown stronger.

In the past, primates from those areas muffled their public criticism out of concern for the more than $4 million in annual funding they receive from the Episcopal Church and individual dioceses and parishes for pastoral, educational and medical needs.

That is no longer the case.

Before Robinson's confirmation, Archbishop Peter Akinola, head of the communion's single largest province -- the 17.5-million-member Anglican Church in Nigeria -- compared the priest's election to "a satanic attack on God's church." He also severed the province's relationship with the diocese of New Westminster in Vancouver, Canada, because its bishop has sanctioned same-sex blessings.

"These are people who have felt their oats," said Allen Guelzo, an Episcopal Church historian and dean of the Templeton Honors College at Eastern University in St. Davids, Pa. "They are autocrats at home and they're going to come in there expecting to be heard and demanding to be heard."

Don Armentrout, a professor of church history at the University of the South, disagrees. He doesn't think the African and Asian leaders have enough power yet to sway a majority of the primates.

In addition, he said, while they may be upset about the Episcopal Church's confirmation of Robinson and the blessing of same-sex unions, western Anglicans are appalled that polygamy is still approved in some provinces of Anglican Africa. Provinces ruled that men who had multiple wives when they joined the church could keep them but not have additional wives.

"I'm sure the communion will issue some kind of conciliatory statement," Armentrout said. "They did not come together to censure one another about issues."

Might individual dioceses in the Episcopal Church splinter or secede from the church if this week's Anglican Communion meeting takes no action?

Guelzo doesn't thinks so. He said the Anglican Communion's dedication to unity is "its primary theological virtue. . . . Once the overarching unity, once the C-clamps are taken off, [Episcopalians] tend to fall into the most divisive and ridiculous factions," he said.

"Anglicanism doesn't lend itself to succession movements. Anglicanism is not the kind of thing that works in small rooms."