The switchboards at local radio stations lit up. James Piecowye, a talk show host, said he had devoted several broadcasts to the subject, with both expatriates and locals openly debating an issue that has long been kept behind closed doors.

“There is this pressure to stake out your claims, especially with the locals,” Mr. Piecowye said. “There is more and more pressure to say, ‘This is how things should be.’ ”

Dubai, for example, has long had strict rules about public behavior — a man and woman kissing in public can be arrested; one can be ticketed for dress baring too much skin, or for eating or smoking during daylight hours during Ramadan, and altercations with locals can sometimes land expatriates in detention.

But with millions of tourists passing through here, few such laws are carried out.

Ramadan, which ends this weekend, is a month when Muslims fast during daylight as part of what is supposed to be an intense focus on spirituality, breaking fast when the sun sets. This Ramadan, however, stores stayed open throughout the day, rather than closing for the afternoon, and many restaurants served food during fasting hours; hotels served alcohol at night after breaking fast. Local Muslims as well as those from abroad have continued to complain of a lack of Ramadan spirit as compared with previous years.

“This is still a salad platter with a tomato and cucumber that don’t mix,” Mr. Abdallah says, emphasizing that Dubai can never be a melting pot because foreigners are ineligible for citizenship. “It is a massive experiment in social tolerance and it should be promoted as such. But being tolerant should not come at the expense of the local and national identity.”

At least part of the tensions stem from the deep cultural divide here. For the most part, locals tend to live apart from expatriates and rarely interact socially with them.

As in many Persian Gulf states, Dubai’s ethnic groups also exist in defined socioeconomic stratifications — locals are typically owners, Westerners earn the top salaries and South Asians do the menial labor.