A FEW WEEKS ago, the main impact of the Miss World beauty pageant on Nigeria had to do with fashion and looks. Thanks to the victory of a Nigerian contestant in 2001, the pageant was due to be staged in that country this year. But in recent days the pageant has provoked violence between Christians and Muslims in the northern city of Kaduna, where more than 200 have died and 4,500 have been left homeless. The beauty queens have hastily departed the country for London. But the Bush administration should have the opposite instinct. If it does not help Nigeria's fragile democracy manage its sectarian tensions and incipient violence, a Taliban-style movement may cement control over large parts of the country.

Nigeria's 130 million people are divided, roughly evenly, between Muslim northerners and southerners who are Christian or follow traditional faiths, the kind of split that has consigned Sudan to decades of civil conflict. In the past, Nigeria managed this division reasonably well; politics was dominated by moderate Muslim generals with no wish to inflame religious jealousies. But in the past three years or so, Nigerian Islam has taken a more radical turn. Islamic sharia law, which has long regulated family disputes, has been applied in a much harsher way; two women and a man currently await execution by stoning, sharia's punishment for adultery. Zamfara state has required Islamic dress, banned alcohol and segregated public transport by gender; religious police have been given the power to enforce these measures, acting without oversight from the normal justice system. Zamfara has started to accumulate weapons, apparently to defend its policies against potential federal attack. In Yobe state, which has also embraced sharia, the governor has promised to defend the Islamic code even if civil war is the consequence. In the past three years, sectarian violence associated with the radicalization of Islam has killed at least 10,000 people.

These disturbing trends may owe something to outsiders who finance radical Islamic groups, in which case the U.S. Treasury's task force on the financing of terrorism should move to cut off that money flow. But the radicalization of Islam also reflects the appetite of some Nigerians for an alternative to the corrupt secular institutions that have long failed them. In non-Muslim parts of Nigeria, a similar appetite for very rough justice is evident: In predominantly Catholic Anambra state, for example, the governor has hired a vigilante gang that decapitates suspected criminals and leaves their bodies in the streets as warnings. Until Nigeria's self-serving elites stop ruining the country with corruption and indifference, their countrymen will be drawn to radical alternatives.

There is no doubt this poses a serious threat to U.S. interests. Nigeria is Africa's most populous country. It has plenty of oil, and it is seen by the Bush administration as an important partner as the United States seeks to diversify away from Middle Eastern sources. The administration must therefore step up its efforts to support Nigeria's reformed and secular institutions, and to prevail upon foreign supporters of Islamic fundamentalism to back off. There is, unfortunately, no guarantee that this will work: The United States cannot perform magic in a country as large and unwieldy as Nigeria. But the administration must do anything it can to prevent the triumph of a new Taliban in Africa.