As dusk fell, they danced barefoot on the grass, small children and straw-hatted grannies, fat and slim, rich and poor, white, black, Hispanic-American, Indian-American, Chinese-American, while the irresistible beat of the zoot-suited Big Bad Voodoo Daddy band pounded from the stage. Some of the dancers looked great, others ridiculous, but they didn't give a damn. Then fireworks erupted into the spacious night sky, and a leather-faced man in a cowboy hat cried: "Red! White! Blue!"
The concert to mark Independence Day here at Stanford University in California, earlier this year, showed America at its best. It was an authentic, infectious celebration of freedom and national togetherness, but also of a very particular kind of equality. Not the European kind, which looks to a state-guaranteed social standard for all citizens, but the American kind, which claims that anyone, coming from anywhere, has an equal chance to make their own way to the top.
Where else would you get men and women of such diverse origins dancing so exuberantly together, barefoot on the grass, to celebrate a national holiday? Perhaps in Australia, Canada, or London, which is a small multinational country in itself. But even there, would it have quite the same pizzazz and largeness of spirit?
This was the enactment of a dream, of course. The statistical reality of social mobility in today's United States is rather different. But a dream in which enough people believe is itself a kind of reality, and that has long been the case of the American dream. It's a remarkable fact that, in surveys, many poorer Americans oppose high taxes on the rich - presumably because they believe they might one day be rich themselves. There are just enough success stories of outstanding individuals from poor and immigrant backgrounds to keep the dream alive.
Two months later we saw America at its worst, as members of the black underclass in the ninth ward of New Orleans drowned, grew sick and were preyed upon by violent gangs, while government failed to help or protect them. There are even reports (unconfirmed, and perhaps apocryphal) of American women changing their name from Katrina, since Hurricane Katrina has become a synonym not just for natural disaster but for human and political failure. How could the richest and most powerful country in the world, capable of hitting a flea in Afghanistan with a precision laser-guided missile, fail its own poor so miserably?
And then there was Rita. I returned last week from Iran (where an ayatollah at Friday prayers used Katrina to illustrate the inhumanity of the Great Satan America) to an America engulfed in preparations for the onslaught of Hurricane Rita. Watching television, which reported virtually nothing else, 24 hours a day for several days at a time, this felt like a country facing up to a Martian invasion, as in H G Wells' The War of the Worlds. As the 1938 radio broadcast of The War of the Worlds famously triggered a mass exodus from American cities, so now an estimated one million people fled north from Texas. "Galveston is virtually a ghost town now," reported one correspondent, "which is encouraging." While that multicoloured rotating swirl in the weather-map simulations attacked the Gulf coast again and again, like an alien spaceship, the governor of Louisiana warned people: "If you choose to stay, write your social security number on your arm in indelible ink." So they can identify the corpse, you see.
In the event, it was not so bad as they feared. Three things struck me about this week of Ritamania. First, how often people reached for the word "hero". "Hero docs ride out the storm," said a report on ABC. Of course our tabloids do the same, but this has a different quality and frequency to it. When a military man briefing President Bush said the response to Hurricane Katrina had been "a train wreck", meaning a complete mess, Bush responded: "Having said that about Katrina, there were still some amazingly heroic rescues ... "
It would be interesting to do a word count for mentions of the word "hero" in American public life, as compared with Britain, France or Germany. A hundred years ago, conservative nationalist Germans used to characterise the "true" Germans as heroes and the Jews as wheeler-dealers: Helden against Händler. Today, we have a different stereotype: true Americans as Helden and limp-wristed Europeans as Händler. Yet in practice, of course, you had the same mix of true bravery and, as one journalist on the spot noted, "real raw panic" in the response to Rita and Katrina as you would in most societies.
The second thing that struck me was the way the Bush administration fell back on to the military. After the breakdown of public order following Katrina, members of the 82nd Airborne swept the streets of New Orleans, guns at the ready, as if this was Somalia, Kosovo or Iraq. Not just once but twice in the past few days, Bush has been shown being briefed by military commanders. The president confided that he was thinking about the circumstances "in which the department of defence becomes the lead agency". In the run-up to Rita we were shown the deployment of an entire, fully transportable accident and emergency department, with all mod cons, entirely owned and run by the military. Spick and span, and eerily empty. I could not help reflecting that the poor inhabitants of the ninth ward in New Orleans could have done with one of those in everyday life. But that's not where the money has gone in the past few years.
The third thing that struck me very forcefully was the number of people left destitute, or shouldering mounting debt, by the damage to their homes. Why? Because they had no savings. Indeed, many of the poor evacuees from New Orleans did not even have a bank account. The possessions in the house, some of them purchased on the never-never, were all they had. That's why some poor African-Americans refused to leave their homes. This is not just about poverty; it's also about a consumer culture, a relentless commercial pressure to spend, spend, spend, which has given the United States its lowest average personal savings rate since 1959, and one of the lowest in the developed world.
There's very little padding there to absorb another shock, such as the soaring petrol prices which are America's other current obsession. On Monday President Bush even suggested that Americans might think of driving a bit less. If I had any shares in the manufacturers of gas-guzzling SUVs, I would sell at once.
Now I believe the United States will meet this challenge, precisely because of the spirit and diversity I saw in that Independence Day celebration. This is still a very dynamic society, full of enterprising people who want to be here and want to make it. It's also good at scientific and technological adaptation, which can go a long way to address the country's oil dependency. But as I leave Stanford to return to Europe, I do come away feeling that this country needs to spend the next few years concentrating more on its economy and less on its military. When the next recession comes along, it will be no use sending for the marines.