Here comes the little frog, hoppety-hoppety, across a shiny leaf not much bigger than he, and whoosh, his small pads touch a couple of hairs on the leaf and it snaps shut to squeeze, suffocate and chemically dissolve his body.

This of course is nature in all her vaunted beauty, and the "Death Trap" hour in the television series called "Nature" was itself beautiful. Not only the Venus flytrap (which caught the froglet) but the sundew, pitcher plant, bladderwort and other flesh-eating plants were shown in action and in gorgeous color.

In another memorable scene the long progress of a beautiful insect through egg, larva, chrysalis, ends when the triumphant moment arrives for liberation. The confining case splits, the gorgeous winged creature emerges. And is devoured a few seconds later by a flesh-eating plant onto which it climbs.

Sometimes a little caterpillar is caught halfway inside the Venus flytrap, the other half still outside that dreadful prison, struggling for life. Or, again, an ant is caught in the lethal glue of an animal-eating plant by just one fragile antenna -- surely it can escape, considering the strength of the ant and the slightness of the antenna? But no, all is lost from that moment.

An hour of this and you can easily conclude that life and death are random, brutal and largely senseless. This conclusion is the more readily arrived at if you consider human fate, which bears a glowing resemblance to the flytrap and the little frog dying within it, and him such a little fellow.

It may be the gods kill us for their sport, but long before we had poets to guess it, cave men understood the death-trap theme perfectly well.

It must have been in prehistoric times that men first rebelled against the system, much good that rebellion did them, since they continued to die by the million at random and in ways they did not understand, beyond the perception that the fate of the froglet is the fate of man.

A lot of animals surpass us in elegance of design and general beauty, as well as speed and strength, but we are as lively as any, and as clever. In no time we began trying to think our way out of the kind of nature in which we saw the other animals entrapped.

It galled us that human suffering might be no more consequential than an aphid glued to a stem. Sometimes human efforts at escaping from nature took the form of sheer fantasy, sometimes ingenious denials of our own animalhood. But sometimes analytical thought and lucky experiment led to a new control of nature (some of it) and with this came wider consciousness and new possibilities of action.

Even if the cave man was hardly distinguishable from his modern descendant, his vocabulary was small, his transportation and his wealth were scanty. If he saw a fellow human crushed by a rock, he might have wanted to help but lacked the means.

I well remember old Willingham's surprise (he was an unemployed aged man in Memphis, run over by a truck while on his way to buy two quarts of sherry) that strangers who owed him nothing got him to the hospital, paid his bills, and restored him to his former state of considerable happiness selling the wine at two bits a shot from his alley dwelling. A cave man had no way to express sympathy, no way to help. But now even a slight sympathy can express itself (without too much trouble) in ambulances. In this way, at least, we have advanced, and our world is different from that of the wild flesh-eating plants we saw on television. In other ways our world seems hardly to have changed at all.

At the moment, in America, we stand already delivered from the grave peril of Grenada, and if all goes well we shall perhaps be delivered from the twin Goliaths of Libya and Nicaragua.

In this way we are more secure, possibly, than our ancestors of swamp and jungle. Still, we feel threatened on all sides, as if our power gave us no comfort.

You might suppose, since we are so concerned with security, that the Congress would debate night and day how American power is best used to ensure it, with profound thought given to what makes us secure and what makes us vulnerable. Instead, the Congress seems curiously indifferent to debate on matters of ultimate importance, and far readier to wrangle about which particular billion to give to a certain weapon than to explore ways to beat swords into plowshares. We have a touching faith that if we arm sufficiently, all will be well. As the armor-plated beetle, the swift-winged cranefly seemed armed sufficient to walk over a simple leaf. How could they know the real danger to them was not to the rounded hard shell or the efficient wing, but consisted of two small hairs on a leaf?

Well, they know now. On a particular day they were armed for the wrong thing. As bright animals we know deep down that there is no such thing as guaranteed safety, and that even with every armor known to man there will still be the innocent leaf that can snap shut in a flash or the unsuspected lethal glue on an innocent stem that renders the most sophisticated wings irrelevant. Everybody knows this who ever saw a Maginot Line or a Venus flytrap in operation on the day of crisis.

The widest possible defenses would seem called for, and the most alert stance, avoiding as much as possible (the lesson of the froglet) hopping merrily about as if there were no danger that could not be foiled merely by a quick leap to the pond.

Since we are human, we have resources not merely of steel but of sympathy and human feeling. Some say it is a weakness we must overcome, to feel a sympathy for other nations, and that only by military force can we prevail against such awesome powers as Grenada. And as for questions of what a great republic can "rightly" do, some people think that is the least relevant question of all. There is no such thing as "right," they will argue, pointing to the Venus flytrap that slaughters good and bad bugs alike.

Of all the arguments you hear advanced, for or against American military excursions, there are two you do not hear. One is the dollar cost of operating as we do (and whether this makes any difference in the quality of the national soul) and the other is whether it is right to blast minor nations here and there to keep them from threatening our security.

The ancient Egyptians were the first, perhaps, to invent ethics. They understood dog-eat-dog as well as anybody else, but still dreamed up the notion that there is a talismanic virtue in moral action. Fairness, justice, zub, zub, zub, had practical as well as theoretical value, they imagined.

The idea is by no means dead. Whatever anybody thought or argued at the time, "rightness" had a powerful influence on life and death in the case of the American Civil War, to cite one example, so it is foolish even at a political level to think all you have to consider is what your computer tells you is practically possible in conducting world affairs. There is more in the mix.

Who doubts it is possible to provoke some loon in Libya to show we have a stronger navy than he? Always remembering there can be unforeseen accidents. But what debate has there been whether this is wise and right use of American power? A bunch of young guys get killed, but they were going to die sooner or later anyway, and look at the great lesson we have taught: America can in general out-shoot Libya. Wow. Now the world knows.

The trouble is, there are some things America does not know, not with any deep public confidence, because the question has hardly been considered, let alone debated in Congress or the media or anywhere else, such as the right use of tremendous physical power.

In the meantime, before we finally know how to use power, we do well to watch out for any little hairs on a leaf.