(FORTUNE Magazine) – On the day that President Bush asked Americans to observe a national day of mourning, all the Las Vegas casinos owned by the giant MGM Mirage shut down their tables for a minute of silence. After the minute had passed, the loudspeaker in the casinos played Lee Greenwood's "I'm Proud to Be an American," the country anthem that dominates the Las Vegas soundscape these days, followed by by Greenwood's version of "God Bless America." Afterward, the patter of the tables and the jingle of slots started up again.

That brief moment on Sept. 14 was the only time that the action in Vegas casinos stopped entirely. There may be some who are shocked at the thought that Las Vegas can't bear to close the temples of chance for more than ten minutes. Others worry that the fear of terrorism and the hassles of the new security consciousness will clobber resort destinations such as Vegas.

In response to that criticism and fear, the casino operators have some very good answers: the $48 room plus two free meals deal at the Stardust, and the $99 (down from $300-plus) rooms at the ritzy Mandalay Bay. The Vegas resort operators have perfected the comp-'em-and-they-will-come approach in years of dealing with business slowdowns. It appears to be working again. Occupancy rose from 67% the first weekend after Sept. 11 to a poor but improved 75% the next. Most of the biggest Vegas casinos, including the Hilton and, yes, New York, New York, laid off some workers within days of the attack. MGM Mirage alone has laid off or cut hours for 2,000 to 3,000 employees. (If business rebounds, employees may be rehired.) Vegas is also understandably worried about the ripple effects on the economy--operators of the weakest casinos, like the near-bankrupt Aladdin, have rushed to blame their troubles on the World Trade Center attack.

Harder than reading economic indicators is responding to the question: How can you have fun when the nation is on a near-wartime footing?

The answer, says Oscar B. Goodman, the mayor of Las Vegas, is that it's our patriotic duty. He says the terrorists who attacked the World Trade Center and the Pentagon want to destroy not only our spirit and our way of life (everybody thinks that) but our right to have a good time as well. "No matter how bad the world around us may be," explains Goodman. "We must never get into the doldrums, because that's what our enemies want. The American way is to have a party even in the face of a tragedy."

The mayor doesn't hold a rhetorical candle to, say, Churchill, and he is almost certainly playing to type (what else does one expect the mayor of Las Vegas to say?), but he does have a point. The Declaration of Independence talks about "life, liberty, and the pursuit of happiness," although we have a tendency to think of the third in the series as the least important.

In fact, Las Vegas has the startling ability to turn sadness and anger into a multimedia event. There is no better illustration of this than Greenwood's "Proud to Be an American." (Technically, the song is called "God Bless the U.S.A.," but absolutely everybody in Las Vegas refers to it by the key line of the chorus.) Two weeks after the World Trade Center tragedy, it could be heard at any hour in any spot on Las Vegas Boulevard, no matter how incongruous. At a bachelorette party in New York, New York, guests pumped their fists to it. Lamar Harris, a comic and self-billed "one-man band," played it in his lounge show at the Westward Ho. Treasure Island blared it at its hourly theatrical pirate battles, and the Bellagio let it rip at its lunchtime buffet.

It is a very "Las Vegas Goes to War" approach to the country's unease, but nonetheless it reflects the national sentiment. "You see America more clearly here than anywhere else," says Hal Rothman, author of the forthcoming Neon Metropolis: How Las Vegas Started the 21st Century. It's just that when the country gets into the doldrums, Las Vegas does so in neon and Dolby Stereo.