SOME EXPRESSIONS of Islamic faith that would barely raise an eyebrow in the United States -- wearing a veil in a public building, for instance -- are illegal in Turkey. Adamantly secular since 1923, Turkey has fiercely clung to the image of itself as the modern exception in the Muslim world.

Yet modernism has a way of growing old. Long after its big neighbor to the north abandoned the cult of Lenin, Turkey still adorns every office and every piece of money and every school building with the image of Mustafa Kemal, or Ataturk, the founding father who wore wing collars, outlawed the fez, drank raki with gusto -- and scorned what he saw as the irrationality of organized religion.

The nation Ataturk forged 80 years ago drifts onward. But the world has changed: This is an era of resurgent Islam, and in Turkey it also has been an era of worn-out, corrupt, heavily indebted and unimaginative government. In elections Nov. 3, a new party, with Islamic roots, swept to power.

Its leader, Recep Tayyip Erdogan, says the Justice and Development Party has no intention of provoking the army -- which casts itself as the defender of the secular state -- and every intention of maintaining good relations with the United States and intensifying the pursuit of membership in the European Union.

Mr. Erdogan, who as the popular mayor of Istanbul in the 1990s banned alcohol in city-owned restaurants, cannot now hold office himself because of a conviction stemming from his public reading of a somewhat militant Muslim poem. Yet he's no firebrand, he says. His wife wears the veil, but she stays away from public functions so as not to create an incident.

The party's appeal is primarily economic, in a country that's reeling from inflation and the loss of business because of sanctions against Iraq.

But the economic troubles have been most acute in the Anatolian heartland -- precisely where the Islamic revival has gained the most traction.

There's the dilemma. In power, Mr. Erdogan's party is going to be squeezed between policies pushed by the International Monetary Fund on the one hand and the political and cultural expectations of its Muslim supporters on the other. At the same time it must keep the armed forces happy, or at least quiescent -- and also deal with the stresses of a possible new American war against Iraq.

Yet in one sense the advent of the Justice and Development Party offers an enormous opportunity. To suppress Islam is to invite trouble (as the former Soviet republics of Central Asia have discovered). But to give Islam a moderate and democratic voice would be a genuine and welcome achievement, and a blow against the extremism that seems to be on the rise everywhere else in the Middle East.

The day may come when Mr. Erdogan will have to do battle with the ghost of Ataturk -- and his nation may be the better for it if he wins.