He added, “Their mentality is, ‘Don’t bother me when I’m working.’ ”

The campaign holds special importance as France begins to overcome an economic malaise that has deepened a sense of moroseness in the country. This month, the French federation of hotels and restaurants reported a 10 percent fall in tourism this year compared with a year ago.

Perhaps more challenging is the growing competition that Paris faces, not only from rivals like London, New York and Barcelona, but also from upstart tourist destinations in the Asia-Pacific region. Last year, more than 20 percent of the world’s vacationers visited an Asian city; the region earned $324 billion in international tourism receipts — a full 30 percent of the global total, according to a United Nations World Tourism Organization report. By contrast, the United States earned $126 billion from tourism, while France earned $54 billion, less than China and Spain, the report said.

“There’s a huge economic battle going on between the world’s tourism capitals,” Mr. Navarro said. Just 15 years ago, he said, there were about 60 major destinations; today, there are about 600. “If we don’t improve our service, we will lose money.”

But is the effort really necessary? After all, countless visitors leave the French capital enchanted by their experience, having never lived the legend of snooty service.

“I can’t think of any time when I’ve been treated rudely,” said Paul Sanger, 74, an Atlanta native who said he had visited Paris more than 100 times over five decades. “A lot of Americans think the French are being rude because they can’t understand them. But a lot of it is a cultural thing.”

To many foreigners, Paris is easier to navigate than ever. Today, English has become the new French for an army of young Parisien waiters who switch between the languages with ease, and even pride, when they hear a foreign accent. And many of the 600,000 Parisiens employed in the tourism industry place a premium on politesse.

Still, “snobisme” is hardly a relic of the past, and even the French complain about a perceived lack of civility among some of their big-city brethren. A spate of mocking television ads by the newspaper Le Parisien a few years ago, showing Parisiens cutting in line and leaving poodle droppings on the sidewalk, provoked knowing laughs. And this is by no means the first time the government has encouraged a more polished image: in 1995, a “Bonjour” campaign urged people to be pleasant to tourists, echoing several similar efforts since World War II.