About two and a half thousand years ago, the historian Herodotus records, the Persian tyrant Xerxes was rampaging through northern Greece at the head of the greatest army the world had seen. He had forced the pass at Thermopylae, and now had an apparently clear run of less than 200 kilometres to Athens; but Thermopylae had made him wary. The battle had been a long and bloody one, eventually won not just by superior force but through the collaboration of a Greek traitor. Anxious to know what other defences the Greeks might mount, Xerxes summoned captives before him for interrogation. They were willing to talk, but were not very helpful.

It was the month, they explained, of the quadrennial Olympic Games. For the duration of the games a sacred truce was invoked, and the young men from every state in Greece converged on the plains of the western kingdom of Elis to compete in various athletic contests. Hostilities would be resumed when the games were over. Xerxes was nonplussed: for what great prize were the Greeks competing? Presumably gold that would bring them wealth for life. Well, no, replied the captives: "They get a wreath cut from a wild olive tree."

Xerxes shrugged: the Greeks were obviously crazy. But one of his counsellors was worried. "What manner of men have we come to fight," he asked, "who will do so much for honour alone?" And Xerxes found out, as he pressed on to defeat at Salamis and Plataea in the battles by which the Greeks secured democracy for themselves, and ultimately for the world.

This story is usually remembered as an illustration of the harmony and heroism of the ancient Greek civilisation, but it also makes the more mundane point that in 480 BC sport and politics were regarded as separate and complex issues, each with its own place in a balanced society. In 2007 this is no longer the case, and one reason that both have become simplified and debased is that they have become hopelessly entangled with each other.

It is easy to document the way sport has become politicised: the ancient Olympics themselves fell into disrepute when Roman plutocrats, including the emperors, took over the chariot races through bribery and intimidation, in order to secure the coveted wreath - for themselves, not for the drivers or the horses who won the event in their name. The modern Olympics have followed the tradition, with every games since the idealistic revival of 1896 becoming more nationalistic. The Berlin Games of 1936 are frequently cited as the worst example, but the politicking and corruption of the International Olympic Committee has also been spelled out by the investigative reporter Andrew Jennings, among others.

In other sports, the politics may be less nationalistic but are no less ruthless; administrators, at every level from the international to the provincial, are engaged in a constant power play. Those whom the cricketer Ian Botham described as the gin-soaked old farts now seek to control every aspect of the lives of the players, on the spurious grounds that their charges are role models who need to uphold the reputation of their calling. Somehow, the same standard is never applied to entertainers and musicians, let alone to those who are, in theory at least, at the top of the pecking order: the politicians themselves.

But if politicians are not judged by the same stringent standards as athletes, they now speak very much the same language. Politics is no longer war without blood; it is just another form of sport. The 2007 federal election campaign was characterised by an almost complete absence of a genuine sense of vision, of any attempt to involve the electorate in what Paul Keating once called The Big Picture.

In a sense this was understandable: anyone who was suspected of stepping outside the parameters set by the commentariat ran the risk of being convicted of that ultimate political crime, being out of touch with ordinary Australians. Everything revolved around scoring points against opponents. The media reported the campaign in exactly the same way that it might a prolonged sporting contest. Who ‘won the day', and who ‘won the week'? This had nothing to do with the merit of what was proposed; it was entirely about its perceived reception, as determined by analysts and opinion pollsters. The aim was to ‘grab the lead' or, if behind, to ‘find an opening' and ‘get back in the game'.

An enormous amount of attention was devoted to blunders and gaffes - otherwise known as ‘free kicks', ‘unforced errors' or ‘missed opportunities'. Politicians were said to have ‘the runs on the board', or to be ‘sparring for advantage' and searching for a ‘knockout blow'. Even the solecisms of sporting parlance were brought into play (see, I'm doing it myself). The polls were said at various stages to threaten the government with annihilation and decimation, which were used interchangeably. In fact, annihilation was never on the cards: even in its worst moments, the Coalition was never in danger of being wiped out altogether. And, of course, it would happily have settled for decimation: the loss of a tenth of its seats would have left it with a comfortable majority.

This deliberate dumbing-down is exacerbated by the pleas of some politicians to put sport, rather than politics, on the front pages of the newspapers. And it has become customary for the politicians themselves to downplay their roles. Last year our head of government did not help with his Ginger Meggsish comment that the captain of the Australian cricket team was actually the highest office in the land, and Sir Donald Bradman the greatest ever Australian.

The suggestion that the political process is no more important than a game in which the only objective is to win, like a Twenty20 cricket match in which no one is really interested in skill or subtlety or even cares about the result for more than 24 hours, is enormously damaging to the democratic ideal. We have already debased the system to the point where Australians routinely expect their politicians to lie, break promises and implement policies for which they have no mandate; many are alienated to the point where they resent even having to cast a vote every three years. After all, if it matters no more than any other transient sporting event, why bother? You might as well stay home and watch it on television.

And if this is where we're heading, you have to wonder why the Greeks bothered all those years ago. The barbarians have triumphed anyway. But perhaps it's not quite over: we may be in injury time, but the full-time siren is yet to sound. And there is, as always, a phrase for the situation. To politicians and media alike: Lift your game!