In case you hadn't noticed, we're receiving a massive political science lesson in how the world works -- by crisis. We prefer to think that our system operates mainly on the basis of rational discussion and orderly action. Dream on. The rule of reason is one of our comforting illusions. It is the guiding spirit of op-ed pages, political speeches and college seminars. It is not the way of the world.

Look around. It's not just the Persian Gulf. It's also the budget, the savings and loan scandal, Eastern Europe and the Soviet Union. President Bush and congressional leaders are being swept along by events. They're improvising responses and making up policy by the hour, day and week. It's akin to riding the rapids: they're trying to look calm, while hoping they won't capsize. Crises are perilous, precisely because they shatter old assumptions and reveal new truths. People are forced to do things that they would prefer not to do or had never before considered.

Our Persian Gulf deployment was unimaginable -- except by military planners -- even two months ago. Now that it's happened we are only beginning to appreciate its vast implications. How this crisis climaxes will obviously affect the price (and availability) of oil. But it will also affect future U.S. foreign policy. A setback in the Gulf could breed isolationism -- and vice versa. If cooperation with the Soviet Union works, it may spur more cooperation -- and vice versa.

There's a tendency to disparage "crisis management" as an inferior political skill. You know the rap: better "leadership" could have prevented the "crisis" (whatever it might be). There's a tinge of truth to this. Some crises are consequences of our blunders. But mainly the argument is bogus, because it wrongly assumes that all crises are avoidable. It assigns superhuman qualities to mere mortals. They should grasp the future implications of present events and then forestall catastrophe. Sometimes this happens. To expect it always is utopian.

President Bush surely understands what's at stake for him in the Gulf. Great presidents (Lincoln, Franklin D. Roosevelt, Truman) often owe their reputations to crisis leadership. Their lesser failures are forgotten. By the same token, many presidents have been destroyed by crises, despite other accomplishments. Lyndon Johnson was devoured by Vietnam, Jimmy Carter by the Iranian hostage crisis. Good as Bush's performance has been so far, the story has barely begun. Because a crisis offers an opportunity to do normally impossible things, the potential for big gains or errors is huge. Remember Carter's failed desert-rescue mission.

It's easy to be jaded about this process. Every crisis is automatically exploited by political groups for their own purposes. We are already seeing this in the Persian Gulf crisis. Defense contractors are plugging to save their weapons programs from budget cuts. Oil companies are urging more offshore drilling. Environmentalists are pleading for policies to promote energy conservation. So what else is new?

It's also true that "crisis" is one of our most overused words. The distinction between an everyday (though serious) problem and a genuine crisis has virtually vanished. We have a school "crisis," many health care "crises," countless environmental "crises," a welfare "crisis," a day care "crisis," a drug "crisis" and repeated economic "crises." Our political and media culture heightens our sense of alarm to attract attention and generate legislative action. But in practice, our political system routinely distinguishes between problems and crises.

Consider the budget deficit. In the early 1980s, it was denounced as an impending disaster. When predicted calamities (higher inflation, prolonged recession) didn't occur, pressure to cut the deficit dissipated. Needing a crisis, Congress then created one: Gramm-Rudman-Hollings. By requiring spending cuts if deficit targets aren't met, the law aims to compel action by making the alternative worse. In fiscal 1991, many government programs would be chopped by a third. Airline congestion would worsen, parks would close, medical research would be curbed. Of course, there's a catch. Because the crisis is artificial, it can be avoided by changing the law and not dealing with the deficit.

This is the dark side of crisis governance: we often won't face a problem until it overwhelms us. A few years ago, I wrote a column criticizing myself for not warning of the savings and loan scandal. I repeat those charges of personal incompetence. But I doubt that even a dozen incisive, outraged columns would have made much difference. There are plenty of areas (the desirability of cutting the deficit, imposing an energy tax and expanding the strategic petroleum reserve, to name a few) where repeated pleas for action -- by me and others -- have had no practical impact.

The power of reason simply palls before the power of events. We need to be jolted. That's one explanation. But there's also a second: the deceptive legacy of past crises. One reason that the savings and loan debacle went unnoticed for so long is that it was unlike anything that most journalists, economists or lawmakers had ever known. It was hard to imagine hundreds of financial institutions going bust at once. We could visualize a few dozen. A bigger collapse could occur (we thought) only as a result of a panic in which terrified depositors destroy a banking system by withdrawing their money simultaneously. This is what had happened in the Great Depression, which was our reference point. It was the wrong reference point.

We are usually fighting the last war. You can deplore that, but you can't change it. It's human nature and applies to all societies. We are prisoners of our collective memories. This is another (and less recognized) reason why crises are so important. Beyond creating new realities at the time, they are such great departures from expected events that they condition the way people think and behave for years. The Great Depression, World War II and Vietnam -- all great societal crises -- have influenced how Americans have acted in dozens of areas for decades.

The same thing is happening today. Crisis governance, though often not the best way of handling our affairs, is often the only way. We are now writing our future history. The right question to ask is not why we have crises but whether our leadership is good enough to handle the ones that we must inevitably confront.