By PAUL VITELLO

For many Muslims, nothing since the 2001 attacks has crystallized the difficulties of being both American and Muslim like the fight over a Muslim Community center near where terrorists claiming to act in the name of Islam killed more than 2,700 people.

The storm of debate over building the center, to be called Park51, has attracted intense opinions. But the outcome could have its most lasting impact on the estimated 600,000 Muslim residents in New York and its suburbs.

Some said they felt embittered or hurt by criticism of the project, and of Islam in general, yet understood opponents’ misgivings. Others said Muslim-Americans should continue to push for the center’s construction as a means of asserting their full citizenship rights - but not too hard, lest they draw even more resentment.

A few said they wished the project had never been proposed. “It’s been nine years, but it feels like we haven’t moved an inch since then to come to terms with the issues,” said Muntasir Sattar, 30, an anthropology student at Columbia University in New York.

Many are grappling deeply, through the current tension, with the lingering ambiguities of their place in American society nine years after September 11. Malik Nadeem Abid, an insurance agent in the Brooklyn borough, said he was “not a big fan” of the decision by the Cordoba Initiative, a Muslim group that promotes interfaith cooperation, to build the center near ground zero.

“No one wants a center in downtown Manhattan that stands as a permanent fixture of this terrible tension,” said Mr. Abid, 45. Yet, the decision has been made, he said, “and we can’t let the loudest voices dictate what happens.”

That kind of ambivalence over the downtown project, some said, was partly the point: Muslims in America embody the same diversity as everyone else. Majeed Babar, 39, a Pakistani journalist living in the Queens section of the city, says he talks to people concerned for the safety of their loved ones.

“People just want to be able to go to work and support their families, and not worry that their children will be attacked in the streets because of all this drumbeat of anger,” he said. At the Jamaica Muslim Center in Queens, Imam Shamsi Ali, the director, said the debate over Park51 was almost a distraction from what he believed was the real concern: “the Islamophobia that is causing the same resistance to the building of mosques in Staten Island and Tennessee and California.”

He added, “I am more worried about the larger issue than about whether this project succeeds or not.” Moinul Haque, 25, a soft-spoken graduate student, winced when asked about the hubbub over the Manhattan center. He was, he said, a little resentful at having to defend Muslims’ citizenship rights in “a wholly artificial controversy.”

But he felt that the center’s developers should not unilaterally withdraw. “It has to be worked out,” Mr. Haque said. “There has to be dialogue.” Misunderstandings only compound themselves unless confronted, he said.

That was exactly the concern of Ahmed Habeeb, president of the Islamic Center of Long Island, just east of New York. Because the festivities marking the end of Ramadan this year were to occur close to September 11, Mr. Habeeb asked that residents not misinterpret the party atmosphere at the mosque on that final evening.

“It will not mean that we are celebrating the 9/11 attacks,” he said. “It sounds strange to have to say this, I know. But in this climate you can’t be too careful.” Mr. Habeeb said he was tired of talking about the planned center.

“If I were in charge, I would probably rethink the whole thing for the sake of communal harmony,” he said. “But there are risks in backing off. “If we back off on it, it could be seen by them as ‘One down, two thousand to go,’ ” he said. “It’s very complex at this point.”