PARIS — There is a striking passage in Thomas Jefferson's message to Congress of 1803, during the pause between the French revolutionary wars and those, to follow shortly, of Napoleon's Empire. He said, ''Let us bow with gratitude to that kind Providence which . . . guarded us from hastily entering into the sanguinary contest, and left us only to look on and to pity its ravages.''
He went on to say that ''we should be most unwise, indeed, were we to cast away the singular blessings of the position in which nature has placed us, the opportunity she has endowed us with of pursuing, at a distance from foreign contentions, the paths of industry, peace and happiness; of cultivating general friendship, and of bringing collisions of interest to the umpirage (sic) of reason rather than of force.''
In short, he was an isolationist. The Gulf war has reopened the old American debate between the globalists and who I will call the Jeffersonians. I say Jeffersonians rather than Washingtonians (although it was George Washington who provided the charter of American isolationism, warning the nation against ''entangling alliances'') because Jefferson was unmistakably an American exceptionalist, as is George Bush. Both hold the U.S. not like other countries.
Mr. Jefferson believed that the United States is unique, that ''this whole chapter in the history of man is new'' -- the United States the ''world's best hope.'' But he held that Americans should cultivate national virtue and prosperity within America's borders. Mr. Bush believes that we have an obligation to export virtue and liberty, so as to make a better world.
Mr. Bush's State of the Union message in January was an unqualified statement of American uniqueness. ''Among the nations of the world only the United States of America has both the moral standing and the means'' to create ''a new world order . . . . The hopes of humanity turn to us. We are Americans; we have a unique responsibility to do the hard work of freedom,'' and so on and on in words that over the past five decades of daily use have lost virtually all meaning even to those who employ them.
These phrases of American exceptionalism, by which we praise ourselves and say how different we are from all the rest, have become the ostensible warrant but also the ideological disguise for an American foreign policy actually driven by a variety of frequently uncoordinated and unanalyzed practical considerations.
In the Gulf our motives are protecting oil sources, rejecting aggression, living up to alliance guarantees to Saudi Arabia and Israel, fear of the implications of Iraq's Western-supplied weaponry, etc., each of which would suggest a specific and limited war aim. But it all comes out in presidential speeches as America's leading ''the struggle to preserve and extend the blessings of liberty.''
Ideologies usually are hard and specific in what they promise and demand. America's ideology is soft and self-indulgent, its foundation an optimism so powerful as to block serious thought that might place American actions and choices in a realistic historical context. The debate on the Gulf intervention going on in Washington at this moment, for example -- that dominated official interviews on the television talk shows last Sunday -- concerns whether the U.S. should employ tactical nuclear weapons if U.S. casualties rise above some threshold yet to be identified.
A titanic optimism surely is necessary in order to think that the United States could take the major part in a war in which more than a million troops are in the field and not suffer substantial casualties. It requires an enormous optimism and ignorance of the realities of the contemporary world to think that the recourse to nuclear weapons is a useful option for national consideration and debate today, whatever American casualties.
Americans are capable of such optimism, I suppose, because nothing bad has happened to the country in nearly a century and a half, since the Civil War, so it is conventional to think that nothing bad ever will happen. World War II was bad, but not very bad for Americans: Civil society was totally spared, and military casualties were less than a quarter of 1 percent of population.
Totalitarianism, genocide, purge, prisons, labor camps, betrayals, denunciations -- the characteristic experiences of the 20th Century all have passed the United States by. There was a skirmish with poverty in the 1930s, but since then the U.S. economy has profited from world crises, war and cold war. Vietnam was a national trauma, because at last we failed. The Gulf war is in considerable part an attempt to demonstrate that the failure in Vietnam didn't count.
Another American Founding Father, Benjamin Franklin, once observed ''that there never was a good war or a bad peace.'' One might argue about the first part of that proposition, but it is a plain statement of a plain thought. American leaders no longer seem capable of plain language or plain thought, being incapacitated by optimism.
It is an incapacity that separates the United States from the rest of mankind, whose experience signals pessimism, dread of war and fear of its consequences -- fear of the future. The Gulf war will test whether they, the majority, are right, or whether we Americans are, as Mr. Bush assures us, truly exceptional -- our ''best days'' still ahead.
William Pfaff is a syndicated columnist.