ISTANBUL — As economic contagion tarnishes the European Union, a newly assertive Turkey is increasingly looking east instead of west, and asking a vexing question: Should Turkey reject Europe before Europe rejects Turkey?

When Recep Tayyip Erdogan , the charismatic prime minister, first swept to power in 2002, he made Turkey’s entry into the European Union his overriding goal. Determined to anchor the country to the West, Mr. Erdogan’s Muslim-inspired Justice and Development Party tackled thorny issues like improving minority rights and easing restrictions on free speech to move Turkey closer to Western norms.

But Turkey’s bid was greeted with skepticism and even disdain by some members of the union, not least because of Turkey’s large, almost entirely Muslim population. The negotiations dragged on endlessly without ever yielding a clear pathway to membership.

Now it is Turkey that has soured on the idea, analysts here say. With Europe shaken by a spiraling credit crisis and the tumult of the Arab Spring creating opportunities for Turkey to wield new clout as a regional power, people here are weighing a step that would have been unthinkable only a few years ago: walking away from the European Union altogether.

“Prime Minister Erdogan wanted to be the first conservative Muslim leader who would bring Turkey to the West, but after Europe betrayed him, he abandoned those ambitions,” said Erol Yarar, the founder of a religiously conservative business group of 20,000 companies that is close to the prime minister. “Today, the E.U. has absolutely no influence over Turkey, and most Turks are asking themselves, ‘Why should we be part of such a mess?’ ”

Turkey’s increasingly muscular foreign policy in the Middle East was in evidence last week when it imposed tough sanctions on Syria and made preparations for possible military intervention. And Turkey has become a powerful voice of regional outrage over Israel’s treatment of Palestinians, especially since it froze its ties with Israel over a commando raid on a vessel that tried to reach Gaza from Turkey.

Meanwhile, Turkish officials say relations with the European Union have reached a state of hopeless disrepair, made worse by the prospect of Cyprus taking over the rotating presidency of the union next year.

Turkey has been locked in an intractable political fight with Cyprus since 1974, when it invaded the island to prevent a proposed union with Greece and set up a rival government in the ethnic Turkish part of Cyprus that only it recognizes. In London last month, President Abdullah Gul disparaged Cyprus as “half a country” that would lead a “miserable union,” Milliyet, a Turkish newspaper, reported. Then, when France took the unusual step last week of proposing that Turkey be invited to take part in a meeting of the union’s foreign ministers to discuss Syria, Cyprus vetoed the idea.

A century ago when the Ottoman Empire was crumbling, Turkey acquired the unwelcome nickname “the sick man of Europe.” Now many Turks cannot help but gloat that Turkey’s economy is forecast to grow at a 7.5 percent rate this year while Europe is sputtering.

“Those who called us ‘sick’ in the past are now ‘sick’ themselves,” Zafer Caglayan, Turkey’s minister of economy, said recently. “May God grant them recovery.”

It is all but certain that Turkey’s membership talks, which have made scant progress in many areas since 2006, will make none at all when Cyprus takes over the union’s rotating presidency in July 2012, because the Turkish government has said it will boycott the presidency, effectively freezing negotiations. If the talks are still deadlocked in 2014, Turkish officials say privately, they could be abandoned.

Public opinion in Turkey has already turned away. According to surveys by the German Marshall Fund, 73 percent of Turks saw membership as a good thing in 2004, but only 38 percent felt that way by 2010.

The country’s minister for European Union affairs, Egemen Bagis, said in an interview that Turkey remained committed to joining. With its young and dynamic work force, large domestic market and growing regional role, he said, Turkey would be a bigger asset than ever to the teetering union.

“Hold on, Europe,” he said, “Turkey is coming to the rescue.”

But business people in Turkey, who have long supported membership, are finding it harder to make the case.

Mr. Yarar, the business group leader, owns 404, a chemical company, and Lezzo, a food company, which makes the country’s well-known apple tea. He noted that Turkey’s trade patterns were shifting eastward: though Europe still bought about 56 percent of Turkey’s exports in 2010, some 20 percent went to the Middle East, compared with 12.5 percent in 2004. “It may take 10 years, but the Arab Spring will make these markets even more attractive,” he said.

Cooler relations with Turkey are costing Europe influence in the Arab world, where Turkey, a NATO member bordered by Iran, Iraq and Syria, is fast becoming an important interlocutor for the West. For the first time in decades, analysts say, Europe needs Turkey more than Turkey needs Europe.

To the protesters in the streets of Cairo or Homs, Mr. Erdogan, a pious Muslim leading a prosperous country of 78 million, is a powerful symbol of the compatibility of democracy and Islam, while Europe’s perceived hostility to its Muslim residents undercuts its influence in the region.

Senior Turkish officials say that Mr. Erdogan has turned away from Europe and embraced Washington instead, a development signaled when Turkey announced sanctions against Syria. While Mr. Erdogan coordinated closely on the issue with President Obama, the officials said, Europe played only a supporting role.

The waning of European influence may also corrode Turkey’s ambition to be a model of democracy for the Arab world. Human rights advocates say that without the viable prospect of European Union membership to motivate restraint, the Turkish government’s authoritarian streak is growing unchecked. A report by the European Commission in November said that 64 journalists were in jail in Turkey, and one prominent media group that has criticized the ruling party was hit with a $2.5 billion tax fine.

In this abidingly cosmopolitan city, though, even ambitious and well-educated young people are fed up with the European Union. At a bustling cafe on the western side of the Bosporus, the strait that cuts through the city and separates Europe from Asia, Tugce Erbad, 19, a student of international finance, said her generation of Turks was not interested in joining a sinking European Union. Yet she insisted that she and her friends were still more drawn to Europe than to the Arab world.

“I would rather go to Paris than Beirut,” she said, before quickly adding: “Turkey is neither east or west. We are moving in our own direction.”