WHEN THE PRESIDENT spoke of the decline in America's confidence in its future - which all of its anxious but hoping allies regard as a real and ominous phenomenon - my mind fixed immediately on one of its most obvious but almost unmentionable causes. The once rumbunctious American spirit of innovation and adventurousness is today being paralyzed by the desire to build a risk-free society.

No other great industrialized society has reacted with what can only be described as such palsy to the accident on Three Miles Island. It is simply beyond the bounds of credulity that the French would halt or reduce their huge nuclear power program - would forego their own chance to be "energy-secure" - in response to the kind of misadventure that is naturally to be expected in any humanly inspired endeavor.

Yet in his television address, the president of the United States did not dare to mention nuclear power, and on the following day he corrected the omission only in a muted and almost strangled voice.

No other country took it into its head to ground the DC-10s for as long as did the United States, and I hope that Sir Freddie Laker and the operators of other airlines will succeed in their suits for damages. After the remarkable record for efficiency and safety that has been set by the American aircraft industry in its fleets of planes which today carry the traffic of the world, one engine falls off one aircraft in circumstances that are unlikely ever to be repeated and the American authorities seem almost to set out to destroy the reputation of as trustworthy a commercial aircraft as is now flying.

But these are only the two most recent and glaring examples. The desire to build a risk-free society runs through the whole of American life today. It is draining the spirit from America's inventiveness and from its hope for the future.

If the American people for the first time no longer believe that life will be better for their children, it is at least in part because they are beginning to think that there will be no food which their children will be able to eat without dying like rats of cancer, no form of transport that will be considered safe enough to get them from here to there and in fact nothing that their children may safely do except sit like Narcissus by a river bank and gaze at their wan and delicate forms as they throw the last speck of granola to the fish.

The desire to build a risk-free society has always been a sign of decadence. It has meant that the nation has given up, that it no longer believes in its destiny, that it has ceased to aspire to greatness, and has retired from history to pet itself.

If many more safety regulations are introduced in the United States, it might as well have men with red flags walking in front of the automobiles. Ralph Nader seems sometimes to be interested in designing not motor cars but baby carriages, and even then the baby probably would be suffocated by air bags. He appears not to be aware that one of the main uses to which cars are put is necking, and that this is very difficult if the yearning couple are held back by a harness of seat belts that would hold down even a unbroken stallion.

In no other country is the faddishness of environmentalism so rampant as in America today. If some of the more extreme of the environmentalists had their way, there would have been no industrial revolution, no burst of industrial might in America at the end of the last century, none of the brilliant inventiveness of its technology in the past generation, and, as a result, millions of Americans would still be living the confined lives of the past, and many more millions in Europe would be enduring existences of mere serfdom, their lives bound within (as Marx put it) the narrowest possible compass.

There is a way in which much of my writing about America as an outsider has turned on these questions. For although I am often cheerfully bemused by the more fanciful and extravagant displays of American technology and gadgetry, and although I think that they are sometimes carried too far, so that people may soon use a Cusinart to scramble an egg before they cook it, I have no doubt that in important ways it is here that lies the genius of the country; for what it all says is that things "ain't necessarily so." Do not Americans now distrust their future because they are being told that the things (including nature) are necessarily so?

Zero population growth is the purest expression of the risk-free society. Preciously and exquisitely "I" am here; there are enough wild berries for "me" at least to live on; let no one else come and spoil it.

Back to Eden: For what was Eden but a garden of zero population growth; and indeed what was it but a risk-free society of two? But whenever I try to imagine the life of Adam and Eve, before their fall, it seems to me that it must have been one of infinite boredom.

But the more one thinks seriously of their boredom, the more one realizes why mankind had to escape into risk. Part of the malaise of the American spirit at the moment seems to me simply an expression of boredom. It hangs like a pall, worse than any pollution, over the lives of the people. There is no ship to board; it has been laid up as unseaworthy. There is no carriage to the stars; it might fall like Skylab. It is dangerous to dream; one might feed in one's sleep on a carcinogen. Feverishly and fretfully, the unused energy is spilled out, into the frenzy of white water and the disco.

I turn from the notion of a risk-free society to the epic of Homer, to the magnificent testimony to a people's will in the Old Testament, to the sagas of the Vikings and the daring of the Elizabethans, and there is not a hint of a safety regulation in one of them. But turn nearer to hand. It was not just the wretched and oppressed who came to America, but the wretched and the oppressed who would risk. It was the strong, and not the weak, who came, and then still came. They did not ask if the Mayflower was seaworthy - it was a miserable hulk even for its times - and into our own century they still got onto tubs that might break apart to cross an ocean. What I feel most in Americca now is the ever more constricted sinews of a country that was made by such people.

Soft and swaddling are the constraints - do not do this because it might hurt you; even worse, it might make you fell "uncomfortable" - but they are binding the spirit of a great people like a fetter.

This draining pusillanimity runs into personal as well as into social relationships. The American people are being cajoled into talking to each other as I used to think that only a few people talked to their indoor plants. To ask a president to reach so deep into a malaise is to task too much. What is "wong" with America can be put quite simply. With a Ralph Nader at the head of a wagon train, no one would have made it across the plains, none would have crossed the Rockies and no immigrant would have pushed noisomely out of the gutter.

Risk-free? Living is sweat, danger and death. From those come the laughter. And curiously, from those comes also the ease of heart. CAPTION: Illustration, no caption, By Zarko Karabatic for The Washington Post