Such cynicism is alien to America. The country was born in a rush of idealism. The Declaration of Independence spoke of “self-evident” truths, including the right to national self-determination. It was a universal right, endowed by “Nature’s God.” The corollary: Americans could not join in subjugating another people. In Thomas Jefferson’s words, “If there be one principle more deeply rooted than any other in the mind of every American, it is that we should have nothing to do with conquest.”

At the same time, there was an expansionist streak in the national character. Its roots lay in New World triumphalism. From the first, colonists believed that God singled America out as his “new Israel.” The sense of divine warrant served to justify the Indian wars and the seizure of Western lands. Jefferson himself was not immune to the charms of empire, though his Louisiana Purchase achieved it through commerce rather than combat. By the mid-1840s a new phrase was creeping into the American vocabulary: “manifest destiny,” shorthand for the idea of inevitable U.S. dominion from the Atlantic to the Pacific.

Manifest destiny took concrete form when Congress declared war on Mexico in 1846 over a minor border violation. President James K. Polk barely bothered to disguise his true waraim. He wanted Mexico to give him California. But Americans were not ready for wars of procurement. Horace Greeley raged in a New York Tribune editorial, “Who believes that a score of victories over Mexico, the ‘annexation’ of half her provinces, will give us more Liberty, a purer Morality?” Others saw in the war an attempt to extend slavery. Protests mounted, and in the midterm congressional elections that year, Polk’s Democratic Party lost control of the House. It was an unmistakable repudiation of war policy.

Americans by then were of two minds about war. The country’s religious origins suggested approval of territorial gains; Puritan theology regarded worldly success as a mark of divine favor. But the democratic values that made the United States unique implied a prohibition on foreign intervention except in self-defense. The result was a profound ambivalence about armed conflict as an instrument of foreign policy.

The Spanish-American War of 1898 resolved the contradiction. Theodore Roosevelt knew that appeals to mere interest would never justify conquest. Foreign policy would have to be highminded, moral. War must be virtuous. TR acclaimed the conflict as “a splendid little war; begun with the highest motives.” And when the outcome seemed likely to be acquisition of former Spanish territories in the Philippines, Guam and Puerto Rico, he cast it as a national mission. “The guns of our warships have awakened us to new duties,” he said. “We are face. to face with our destiny.”

Moralism has been the style ever since, especially when the grounds for fighting were unclear. Woodrow Wilson ordered occupation of the Mexican port of Veracruz in 1914 following a military coup, he said, “to serve mankind.” When Ronald Reagan sent U.S. troops into Grenada in 1983, it was in the name of “life and liberty” throughout Central America and the Caribbean. Indeed, according to retired Army Col. Harry G. Summers Jr., in his controversial 1981 book, “On Strategy,” the great mistake Lyndon Johnson made during the Vietnam War was “not to mobilize the American people [for fear] it would jeopardize his ‘Great Society’ programs.” The deliberate decision to tone down the rhetoric, Summers says, cost Johnson the war: “Without the commitment of the American people the commitment of the Army to prolonged combat was impossible.”

‘World order’: For George Bush, the problem is a lack of available ideals. He cannot defend democracy while restoring a feudal order in Kuwait. He spoke at the outset of not rewarding aggression, but the modern world is full of examples of aggression unpunished. Nor will it work to talk, as he did before Congress in September, of a “new world order.” No one knows what that would look like. And because no one knows, the U.S. forces in the gulf cannot use it as a standard for measuring victory. Whatever emerges from the ruins of Baghdad, if it comes to that, it will not be a new world order.

Is realism an alternative to idealism in the current Mideast impasse? Realists deplore–even though it is a political reality–the requirement of public support for the use of force. Henry Kissinger has complained of “fluctuating emotions that [lead] us to excesses of both intervention and abdication.” He is unquestionably right. A foreign policy freed from domestic considerations would be more consistent. But a government can make no more solemn decision than to commit young people to battle. And for what reason? A regime of ideals would at least say: show me.