It has been more than 80 years since religion was ripped out of the heart of the new Turkish state, which was assembled from the remains of the Ottoman Empire, the political and economic center of the Muslim world for centuries. But the portion of Turks who identify themselves by their religion has increased to 46 percent this year, from 36 percent seven years ago, according to a survey of 1,500 people in 23 cities conducted by the Turkish Economic and Social Studies Foundation, an independent research organization based in Istanbul. That is a trend that has emerged in countries throughout the Muslim world since Sept. 11, 2001.

“I’m here as a Muslim,” said Fatma Eksioglu, who was sitting on the grass next to her sister in downtown Istanbul on Sunday at a demonstration of about 20,000 people opposing the pope’s visit. She did not belong to the Islamic party that organized the gathering, she said, adding, “When it comes to Islam, we are one.”

But in a paradox that goes to the heart of modern Turkey, a stronger Muslim identity does not mean that, as in Iraq, fundamentalism is on the rise, or even that more Turks want more religion in their government. Indeed, the number of Turks in favor of imposing Shariah law declined to 9 percent from 21 percent, according to the survey, which was released last week.

Perhaps the most powerful factor pushing Turks toward the east has been a series of bitter setbacks in talks on admission to the European Union. To try to win membership, the Turkish government enacted a series of rigorous reforms to bring the country in line with European standards, including some unprecedented in the Muslim world, like a law against marital rape.

But the admission talks have stalled. And while the official reason involves the longstanding Greek-Turkish dispute over Cyprus, most Turks say they believe the real reason is a deep suspicion of their country’s religion.

Indeed, in 2002, Valéry Giscard d’Estaing, the former French president, said Turkey’s admission to the union would mean “the end of Europe.” Nicolas Sarkozy, the French presidential hopeful, has made his opposition to Turkish membership a campaign issue. Even the pope, when he was still a cardinal in Germany, said publicly that he did not think Turkey fit into Europe because it was Muslim. That talk has begun to grate on Turks.

Image A pedestrian street in Istanbul, where women in miniskirts and head scarves mingle. Turkeys traditional secularism is under pressure. Credit... Lynsey Addario for The New York Times

“It hurts me that the E.U. expects Turkey to be something it’s not,” said Nilgun Yun, a stylish 26-year-old eating a chocolate muffin in a downtown Istanbul cafe on Sunday.