The chief responsibility of the leader of the Anglican Communion is not to be the last leader of the Anglican Communion, a burden that has weighed heavily on the shoulders of the Archbishop of Canterbury, Dr Rowan Williams, for several agonising years. By intervening in the deliberations of the bishops of the Episcopal Church of the United States in New Orleans, he raised the stakes as high as they could go, for had his pleas been flatly rejected a formal split of the Communion would have been inevitable, possibly within days. As it happened, they listened - and moved. Given how strongly American Episcopalians have been attached to provincial autonomy - the principle that no part of the Anglican Communion can dictate to any other part what its beliefs and practices should be - their decision to extend indefinitely their moratorium on consecrating homosexual bishops is a substantial shift in their understanding of what being an Anglican entails.

In the short term there will still be some breakdown in communion at the margins, as more extreme elements denounce the New Orleans formula as not good enough. There is already a small but significant number of Episcopalian clergy who have transferred their allegiance to African dioceses like Rwanda. The danger is that the spirit of rebellion will spread, and the Anglican Communion will gradually unravel, as a series of crises over church order, clashes of jurisdiction and even ownership of property force even moderately minded Anglicans to take sides. Some evangelical bishops in Africa in particular seem keen to impose something akin to provincial uniformity on the American Church, where no deviation from their own hard line regarding homosexuality is permitted and those who ever thought differently are required to repent. But such intransigence is not the Anglican way, and if they push much harder it is they who will be in schism. Dr Williams will have to be as firm with these African bishops recklessly fishing in troubled Episcopalian waters as he has been with the Episcopalian leadership itself.

In the longer term, however, the New Orleans compromise itself looks unstable. The majority of American Anglicans still see discrimination against gay men and women as incompatible with the Gospel, and that includes discrimination against candidates for the priesthood or episcopacy. And they no longer accept the distinction that has helped the Catholic Church handle these tricky issues, between celibate and sexually active homosexuals. So, although a dam has been built, the rising waters may burst through again.

The Anglican Communion has often been a powerful force for good in the world and the cause of Christianity itself would be damaged if it broke up, not least because of the bitterness that would result. Catholics in particular can appreciate the belated realisation in the American Church that unity carries a price that can sometimes be irksome, and a Communion in which every part is entirely free to do whatever it thinks best is not worthy of the name. That acknowledgement now needs to be hammered home and made a central tenet of Anglican identity, not treated as a temporary local compromise to overcome a particular difficulty.