Alexander the Great had many motives. Vainglory, lust for power, competition with his dead father, dread of his mother, eventual madness or obsession: all of these have a place in the record. There was one motivation, however, that can be gathered from Alexander's actions: a desire to change the east through an infusion of Hellenic culture, and to create something great from the synthesis. To this end, Alexander was the first neo- conservative.

Greeks of Alexander's day considered the east a place of inveterate, corrupting despotism. Athenian, Spartan or Macedonian kings, by contrast, were chosen by their peers and consulted them. And neither king nor commoner ever prostrated himself before anyone. A Greek of the classical age prayed standing straight, with his hands to the heavens and his head raised. Individuality and reason - itself the ultimate assertion of the primacy and potential of the individual - were the sinews of Greek humanism. Alexander wanted to bring what Greeks saw as the light of Hellenic civilization to new lands. "We must bring change to the east," says Alexander in Oliver Stone's film. "We will build an empire not of land and gold, but of the mind."

The Hellenistic civilization that flourished for two centuries in Alexander's wake from Egypt to India is one of the glories of mankind. It truly did bring east and west together, putting Hellenic inquiry and individuality at the core of a vast oriental culture. Alexander's first and most beloved wife was an Afghan princess (and if she was half as violent in the imperial bedchamber as Rosario Dawson's Roxanne in the movie, it's a wonder he survived to the age of 33). His other queens were Persian. At Susa in 324BC he organized the wedding of 80 of his leading nobles to local women, and turned the local liaisons of 10,000 of his Greek troops into official marriages. After he finally defeated the Persians at Gaugamela he adopted half-Persian dress, and he ruled through indigenous leaders across the empire. He brought Asians into the inner circle of his court and made them equal generals in his army. He trained tens of thousands of Asian youths as Macedonian soldiers, and the 70 cities he founded with mixed populations gave deep roots to the fusion he sought.

The price to this vision came at the point of the sword, with all of the attendant costs in blood and moral standing. It came at a price to ancient Greek freedoms, and to the humanist ideal as well, especially as embodied in himself, its greatest evangelist. Within three years of his conquest of Babylon and Persia, he had even Greeks prostrating themselves before him. An autocratic style that his fellow Greeks saw as Asiatic tyranny came to dominate his councils. To this day the Zoroastrians of northern Iran remember the mass marriages at Susa as a kind of reverse ethnic cleansing. Alexander's insistence that he was a natural son of Zeus became the subject of jokes even in his own court. As he moved on over the years across Central Asia and Afghanistan and into India, homesick and exhausted Macedonians rebelled against his increasingly obsessive need to go ever further.

Such themes, of course, are truly Greek: hubris (overbearing pride), pothos (longing), pathos (a quality arousing pity) and psyche (the human soul). For Alexander these ideas make the man human as well as great. For Stone their absence makes his $160m film a lengthy and expensive inconsequence.

Early in the film we see a young Alexander studying with his friends at the feet of Aristotle, in what we presume are the famous Gardens of Midas at the court of Alexander's father, Philip of Macedon. The philosopher tells the boys about the Barbarians to the east, vast hordes whose natural condition is slavery and whose destiny it is to be ruled by the Greeks. Aristotle was, above all others, the intellectual architect of Alexander's transformative project in the east.

Like Alexander, George W. Bush was schooled in the classical tradition. In his youthful studies at America's smartest schools he would have received an education that assiduously drew its roots from Aristotelian humanism. There would have been no talk of the natural slavery of Barbarians, but the classical roots of the mission civilisatrice and of The White Man's Burden would have been familiar at Andover and Yale. Bush belongs to the last generation of Americans brought up in the innocence of cultural confidence that John F. Kennedy's "best and brightest", so reminiscent of Alexander's "companions", did so much to destroy with Asian adventures of their own. Thus does the movie come at a good time.

However, near the end of the film, after a three-hour saga so exhausting that even Anthony Hopkins can no longer be bothered to act, one of the 20,000 surviving Greeks who followed Colin Farrell's Alexander for thousands of miles across the Middle East and Asia says, "Let him die before he kills us with his dreams." By this time the audience is identifying with what is happening on screen and has joined Alexander's men in longing for an end to it all. But it is unfortunate that the parallel does not extend to recognizing the conflict between the appeal of great ideas and their danger.

This does not interest Stone. For all the old-fashioned charm of the sword-and-sandal theme, Stone gives us a thoroughly modern Alexander. The two principle themes in the film are Alexander's homosexual love for his pal Hephaiston and his lust/hate relationship with his mother - played by a vampishly Transylvanian Angelina Jolie. It is amazing to see how far this Alexander traveled, how many armies he slaughtered and provinces he devastated, simply to get away from the only woman he ever loved. And this vision of greatness as neurotic and accidental is proving a bust at the box office.

The film's attention to historical detail - at once a delight for classics buffs and a real bore for everyone else - is generally so scrupulous and nuanced that it is a pity to see Stone ignore completely the only historical fact that could possibly drive the film: Alexander was Great. The real Alexander played the lyre beautifully, hung out with poets and could have been a foot soldier or an athlete or a philosopher. Instead, he went east to change the world.

And, while Bush shares the democratic transformation ideas of some leading neo-cons, he, like Alexander, is not truly one of them. Whatever else we might fault Bush for, most of us believe that when he works to bring legitimate government and political freedom to the Middle East, naively or otherwise, he does so because he believes these things are good in their own right.

Deposing Saddam Hussein, holding an election and trying to reconstruct Iraq against the wishes of Russia, Germany, France, Kofi Annan and the local Wahhabis might be a misguided way for him to go about this. And, like Alexander, Bush might have had other motives. He might truly still be upset that Hussein tried to kill his father, or that his father never finished the job in Mesopotamia. (Darius was a main suspect in the murder of Philip, Alexander's father, who was planning an invasion of the east when he died.)

But, when Stone has Anthony Hopkins' Ptolemy say, "Babylon was easier to enter than she was to leave," implying a long-inhibited desire on Alexander's part to get out, he is politically provocative, but wrong: Alexander wanted Babylon to be his capital forever. Babylon was a Greek city for at least 200 years after Alexander. The last Greek king in India, Hermaeus, did not succumb until 30BC, three centuries after Gaugamela. Closer to Greece, from Egypt through Lebanon and parts of Syria to Turkey, Hellenistic city states passed their legacy directly to the Romans, whose high culture and local governance was essentially Hellenistic in nature and kept Alexander's drive alive in the Near East until 600 or 700 years after his death.

When the Arabs came they adopted their philosophy, mathematics, medicine and geography directly from Greek authors, many of whom Alexander and his successors had read. As Europe slept through its Dark Ages night during Islam's long and glorious medieval noon, it was the Arabs of Alexander's old empire who sustained the Greek roots of western civilization.

This "soft power" - the attraction and prestige of a culture, including its arts, philosophy and way of life - is clearly one of the forces that allowed Alexander's Hellenistic legacy to endure. In India, coins were being printed with Greek letters 200 years after the fall of the last Greek king, 500 years after Alexander's death. In Afghanistan, the Greco-Buddhist statues at Bamiyan survived until the Taliban blew them up four years ago. Soft power also helped the west to win the cold war, when anyone with a pulse behind the Iron Curtain wanted to be Californian or listen to The Rolling Stones. It is at work today in Iran, where a huge young population of students is desperate for the freedoms they see through their illicit satellite television channels.

However, soft power is not helping to win the current war in Mesopotamia. On the streets of Sadr City you don't see baseball caps and hear the theme tune to Titanic as you might in Manila or Moscow. They don't watch Baywatch in Babylon. In the cafes they watch al-Jazeera, and in their homes after lunch they lean pillows against their walls and nap on carpeted floors to the trance- inducing Sufi chants on their videos of ambushes, roadside bombs and worse.

In the 1975 film of Rudyard Kipling's The Man Who Would Be King, Michael Caine and Sean Connery are saved from miserable deaths in the mountains of "Kafiristan", somewhere north of India, by an ancient coin bearing a likeness of Alexander. I don't know if the plastic in a DVD will last 2,300 years, but it will be pretty embarrassing if DVDs of Stone's current Alexander film show up to haunt our descendants. It would be far worse if one surfaced in Babylon today. Then they would never take us seriously.