In the penultimate episode of a six-part series entitled Age of Empire, the BBC's Jonathan Marcus examines how US culture is as crucial a weapon in the American arsenal as its military hardware.
The other evening I went to the cinema in central London.
It was, if you like, a professional visit designed to make a particular point about America's place in the modern world.
Virtually all of the films on offer in the Leicester Square cinemas were American. Nothing wrong with that, I hear you say.
Hollywood makes some great movies, and some very bad ones as well.
But Hollywood is also an instrument of American soft power; a phenomenon which, though poorly understood, has a dramatic impact in shaping perceptions of America and American society.
Through American eyes
Take the film that I saw - The Last Samurai, starring Tom Cruise. It is set in 19th century Japan.
It is a story based on a real-life rebellion by a Samurai warlord, against a western-backed - in this case a US-backed - government, intent on modernising the country.
In showing the last gasp of the old Samurai warrior-caste it lets the Americans have their cake and eat it. They are both the villains - the suppliers of the modern weaponry to the government, but an American, Tom Cruise of course, is also the hero.
He is a US soldier who respects the warrior traditions of the Samurai and sides with them.
America's dominance of the movie industry across much of the world is not just a matter of money and big business.
Popular culture celebrates American values and, as in this case, it presents a particular American view of the past.
What is good for cinema is equally the case with television. We went on a location-shoot with the crime series Law and Order on the Lower East Side in Manhattan.
New York is as much the star of this show as the characters themselves. It probably goes a long way in explaining its popularity; it is shown in over 70 countries around the world.
It is no exaggeration to say that the world watches America on its television screens; in effect pre-programming people to accept particular images of American society and reinforcing its attraction.
It all sounds like a sinister plot but the reality is much more banal. There are many things that are attractive about US society and films and TV help to accentuate their impact.
Film stars like Cruise accentuate America's attractiveness
For a definition of what soft power means I turned to one of its foremost theorists, Joseph Nye, Dean of the Kennedy School of Government in Harvard .
"Hard power," he told me, was "the ability to coerce others by using carrots or sticks as either bribes or threats". But "soft power", he said, "is the ability to get what we want by attracting others, by getting them to want the things we want.
"If I can get what I want because you want it too," he said, "it saves me a lot of carrots and sticks."
But hard and soft power have to be used together.
"During the Cold War military containment prevented Soviet expansion but the real victory was the transformation of the cultures behind the Iron Curtain by their attraction to Western values. So soft power was essentially the transformative force," says Mr Nye.
Feasible or folly?
The Bush administration is eager to use soft power to change its image in the Middle East. But it wants to go much further to transform the region as a whole.
The US goal is to bring democracy to the Arab world, starting with Iraq. Cynics see such claims as just window-dressing. Critics have argued that the whole grand plan is over-ambitious at best, and plain crazy at worst.
But a former senior official in the Bush administration, Richard Haas, insisted that such a goal was not just feasible but essential.
"One of the things we ought to have learned from 9/11 is that in this globalised world we potentially pay an enormous price for the inadequacies and flaws of Middle Eastern societies," he said.
"When young men in particular grow up alienated, when they don't have political choices, when they get a terrible education that teaches them religious texts through rote rather than secular issues and concepts of inquiry, these are young men who are simply unable to get real jobs and compete in this globalised world.
"These then are young men who tend to gravitate towards the mosque and they are at a minimum likely recruits to extremism and worse to terrorism."
At one level the logic is convincing. But it is far from clear that Middle Eastern societies want to be democratised by the Americans in quite this way.
At the American University in Cairo, which trains a significant slice of the Egyptian elite, we found thoughtful students, most of whom were comfortable with both their US-style liberal education but also with their Arab identity.
The provost of the university, Professor Tim Sullivan, argued that education is perhaps the best example of the beneficial impact of soft power.
But uncomfortable though it may be to the politicians, education, he insisted, was not a remedy that would work overnight.
Richard Haas agreed that America's great project in the Middle East was the work of a generation.
But the real question is whether successive US administrations will have the staying power to see the job through, assuming of course that it is feasible in the first place.
The Age of Empire series is broadcast on Mondays at 09:05GMT on BBC World Service Radio.
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