The hoariest and most oft-repeated cliche in American politics may be that America is the greatest country in the world. Every politician, Democrat and Republican, seems duty bound to pander to this idea of American exceptionalism, and woe unto him who hints otherwise. This country is "the last, best hope of mankind,'' or the "shining city on the hill,'' or the "great social experiment.'' As if this weren't enough, Jimmy Carter upped the fawning ante 30 years ago by uttering arguably the most damning words in modern American politics. He called for a "government as good as the American people,'' thus taking national greatness and investing it in each and every one of us.

Carter was speaking when Watergate was fresh, and government had been disgraced, but still. The fact of the matter is that whenever anything really significant has been accomplished by our government, it is precisely because it was better than the American people.

Think of World War II, America's entrance into which was strenuously resisted by the populace until Franklin Roosevelt carefully laid the groundwork and Pearl Harbor made it inevitable. Think of civil rights, which Lyndon Johnson pressed despite widescale opposition, and not just in the South. Even then it took more than 100 years. Or think of the current health care debate in which Americans seem to desire some sort of reform, just not a reform that would significantly help people in dire need, while the Obama administration is pushing to provide that assistance. In the end, government has inspired Americans far more than Americans have inspired their government. They are too busy boasting.

There is nothing wrong with self-satisfaction or national pride. But the incessant trumpeting of our national superiority to every other country in the world is more than just off-putting and insulting. It is infantile, like the vaunting of a schoolyard bully that his Dad is better than your Dad. It is wrong. And it might be dangerous both to ourselves and to the rest of the world.

Consider what it means. By what standard is one nation any greater than any other nation? Yes, the United States has vast material resources - we rank eighth in gross domestic product per capita - but we also have, according to the Organisation for Economic Cooperation and Development, the "highest inequality and poverty rate'' in the world, outside of Mexico and Turkey, and things are getting worse. Nothing to boast of there.

Yes, we have a relatively high median income, but our standard of living as measured by the Human Development Index of the United Nations ranks us only 15th in the world, behind, among others, Norway, France, Canada, and Australia. Are they better than we are? Even our home ownership rate trails that of the citizens of Canada, Belgium, Spain, Norway, and even Portugal.

Yes, the United States has the best system of higher education in the world, but, according to an Educational Policy Institute report, we rank 13th in the affordability of that education, and we are much less successful with lower education - 11th in the percentage of the 25 to 34 population with a high school diploma and 22d in science education.

And though Americans love to crow about the "best health care'' in the world, the fact is that according to the World Health Organization Index, we actually rank 37th in the quality of our health care. And we are still the only industrialized country in the world without a national health care system.

Even when one considers anecdotal evidence - "If this isn't the greatest country then why do so many people want to come here?'' - the case isn't particularly persuasive. Mexicans cross the border to the United States for economic opportunity. Turks go to Germany, Indians and Pakistanis to Great Britain, Arabs to France. This isn't a sign of our special greatness, just a sign that desperate people seek a more powerful economy for their betterment.

The point of all this isn't that America doesn't have a lot to be proud of. It does. The point is that just about every country has a lot to be proud of, and America has no more right to assume it is the greatest nation in the world than does France, Switzerland, China, or Russia.

None of this would make much difference if the self-congratulation was just harmless bragging. But there are consequences. A country that believes it is the greatest in the world is also less likely to be constrained by that world. One could argue that the Iraq war was a direct result of a sense of national infallibility. So was our willingness to torture, our reluctance to admit our mistakes in Afghanistan, our culpability in the global recession, and our foot-dragging on global warming. Such a nation is also less likely to introspect or to strive for true greatness because it believes its greatness has already arrived.

There is something bizarre about a country whose leaders have constantly to toady to their constituents and in which any criticism is tantamount to a lack of patriotism, but that describes America today. Every politician feels compelled to ape Jimmy Carter's old words to the point where our alleged greatness has also become our national mantra.

It seems eons ago when Bobby Kennedy, a politician who didn't like to stroke even his own supporters, actually scolded a rally for booing Lyndon Johnson because, Kennedy said, Johnson couldn't have done what he did in Vietnam if he didn't have the American people, including Kennedy's audience, as his facilitators.

We aren't going to hear that sort of honesty from political leaders any more because the American people are too thin-skinned and arrogant to tolerate it. Arrogance in an individual is unbecoming. It is no more becoming for a nation. The Greeks understood that the gods punished mortals for their hubris - for feeling that they were godlike. They knew that overweening pride preceded a fall. One suspects that nations are no more immune to punishment than individuals. A nation that brooks no criticism, a nation that feels it is always better than any other, a nation that has to be endlessly flattered and won't face the truth, a nation whose people think they possess some special moral exemption and wisdom, a nation without humility is a nation spoiling for calamity.

We've been living in a fool's paradise. The result may be a government that is as good as the American people, which is something that should concern everyone.