We live in an age of scandal. Scandal has come to dominate politics all over the world in a way which would have seemed barely credible only a generation ago.

Forget the clash of ideas, the assessment of policies, the judgment on the abilities of public men, and concentrate instead on who gave what to whom in return for what, and who slipped between the blankets with someone other than his wife.

Scandal threatens to become the engine of national politics, a curse on government that we do not know how to lift.

On the one hand, everybody wants clean government, and nobody wants knaves or law-breakers to be in power.

But, on the other, the relentless pursuit of human weakness in those elected or appointed to office introduces a lethal element into public affairs that in time may dissuade even the best from taking part in them.

In the meantime it hampers government by diverting its energies into a constant battle against the allegations that opponents throw up almost by the week.

Bill Clinton's plight is different from that of politicians in other countries only because he is, in addition to being the President of the United States, the closest we have to a global executive.

His inattention now could lead to trouble or worse in any of a dozen places from the Middle East to Russia, and from Africa to the Asian countries striving to reorganise themselves after their economic crash.

Otherwise, his position does not differ much from that of leaders like Silvio Berlusconi in Italy, Narasimha Rao in India, Felipe Gonzalez in Spain, or other figures, past or present, guilty or not guilty, in many other countries.

SCANDAL has brought down leader after leader, and destroyed, perhaps for ever, the hold of long-established ruling parties like the Christian Democrats in Italy.

Even the Asian crisis, to which Clinton now will be giving only half his mind, has its strong element of scandal, scandal which has helped defeat one president, in South Korea, and might well topple another, in Indonesia.

Mostly, what has laid politicians low, or shaken them severely, is the charge of financial impropriety. Sometimes sexual or other personal excess has taken first place. Often the two, as with Clinton, are combined.

If the hook of irregularities in political funding will not catch the big fish, then let us try the barb of sexual misbehaviour.

To understand the problem we face, it is necessary to put aside for a time the question of guilt, and confront the fact that if we do not take care politics could become little more than a dismal process of rival scandalmongering.

In this new world, as soon as a government takes office, the hunt is on for the "facts" that will destroy it.

If this happens, it may well be not because of some single scandal but through an erosion of the authority and legitimacy of a government and its members as scandal after scandal, some proved, some half-proved, some just unresolved, are brought to its door, as the cat brings in the birds it has killed in the garden.

In Clinton's years in office, he has watched the growth of a positive industry of investigation into him, his associates, his aides and his cabinet members.

Ironically, he has financed that growth, involving thousands of man-hours of Congressional time, hundreds and hundreds of witnesses and legions of lawyers, out of tax dollars and out of his own pocket.

He himself owes enormous sums in legal fees, while at least six of his aides and ministers have left government in debt after enduring lengthy investigations into offences which, even if true, were mainly petty things.

As Meg Greenfield of Newsweek wrote recently: "Much of 1997 was spent looking for the elusive quo, as in quid pro quo, and meaning the pay-off.

"What did all those industries and individuals get or expect to get in return for their hefty campaign contributions to incumbents in both parties?"

Why has this happened, not only in America but also almost everywhere else? It does not seem likely that politicians are much worse people than they used to be, so the explanation must be sought elsewhere.

The need of parties for significantly more money than they can raise legitimately clearly pushes them into fund-raising activities that are at least shady and may be criminal. The case for reform in many countries is glaring, but it has not been vigorously undertaken.

Then, undoubtedly, even in authoritarian countries, governmental control of information has diminished and is diminishing.

Thirdly, in democratic states, as ideological divisions soften, political competition takes the form of a contest of virtue and trustworthiness.

The combination of more open government with more claims of virtue is a dangerous one, because politics can so easily become a game of proving that the other party is less trustworthy than yours.

Even if in politics there has always been element of "throw the bums out", this is going further.

That is no doubt why the British prime minister, Tony Blair, sometimes seems to set argument and explanation aside in favour of assertions that he is trustworthy.

America shows very clearly another factor to add to these, which is a new synergy between the press and the law, working in harness to deal with irregularity in government.

As the sociologist Manuel Castells has argued in his masterly survey of these developments in his trilogy The Information Age, the Watergate affair was also a watershed in the politics of scandal. Politicians, journalists and lawyers in many countries all acquired more dramatic and adventurous images of themselves, and different ideas of their duties.

Watergate suggested that giantkilling was possible and sometimes necessary. It undoubtedly triggered changes in the attitudes of the press and judiciary, and of political parties.

Those changes came to a fuller expression after the end of the Cold War, which seemed to mean that more risky games could be played within states without endangering security.

The point here is not whether particular prosecutions or crusades are or were correct, but whether investigation, sometimes necessary and salutary, can become a kind of political sickness, as it may have done in Clinton's America.

When the idea grows that if you search hard enough you will inevitably find something, that this something has to be there, you have reversed the normal course of events in which an apparent irregularity leads to an investigation.

Now, however, the investigation leads to the irregularity - which does not mean that there may not be a real offence, but it may mean that scandal, to the detriment of useful politics, has become an end in itself.