Only in one sense is the war with Iraq not in doubt. The United States and Britain will prevail and Saddam Hussein will fall. What is considerably more in doubt is whether the Atlantic alliance, especially America's relationship with France, will survive the war. It is for that reason that I take it upon myself to issue a demarche to France: Butt out.

To my mind, the French have already done enough damage. Their opposition to the war -- partly principled, partly not -- has no doubt emboldened Hussein, permitting him to drag his feet on ridding his country of weapons of mass destruction. When war comes, it will be not only because America wanted it, but also because France did not.

Now, though, is the time for the squabbling to stop. Whatever happens from here on, France -- not to mention Germany and Russia -- must bear in mind that the American and British troops in the desert are not fighting for oil or to extend American hegemony but to rid Iraq of a barbaric regime that, imminently or ultimately, threatens us all. The good guys will be fighting the bad guys, and no one in Europe should forget it.

As in any war, something will go wrong. As in any war, a civilian facility will be hit. This should be no cause for finger-wagging from the Europeans and simplistic cries about how George Bush is a cowboy fired up on religion instead of liquor. When civilians are killed, America's critics should bear in mind that Hussein kills Iraqis every day.

The White House bristles confidence. This war will be over in a flash. Maybe. But the Bush administration has been repeatedly cocky on the diplomatic front only to be proved wrong time and time again. Its diplomatic initiative has been marked by incompetence, lassitude and insincerity. The United States has been deserted by traditional allies and snubbed by what -- I apologize in advance -- were always considered vassal states, those Latin American countries that almost always did our bidding. Not since the run-up to World War I has diplomacy been so inelegantly practiced.

So if the war is as bungled as the diplomacy has been, the moment will come -- the siege of Baghdad, the use of chemical weapons -- when either France or Germany will be sorely tempted to rush in with a peace plan. This would be a grievous mistake and would poison the Atlantic relationship far beyond anything that has so far happened. Once the war is begun, it must be won. The reckoning with Hussein cannot be postponed once again.

But I must pose a similar demarche to the Bush administration: It better be right. French President Jacques Chirac on Sunday told Christiane Amanpour that "it seems there are no nuclear weapons or nuclear programs" in Iraq.

On the same day, Vice President Cheney asserted just the opposite: "We know he's been absolutely devoted to trying to acquire nuclear weapons, and we believe he has, in fact, reconstituted nuclear weapons." These things can never be determined with precision, but if Cheney is simply mouthing off, he and Bush must someday be held to account.

In his television interview, Chirac spoke eloquently about the U.S.-French relationship. It goes back to Lafayette and the Revolutionary War, to the favors the United States returned first in World War I and again in World War II. Forgive the schmaltzy reference, but no matter how many times I see "Casablanca," my eyes tear when, in defiance of the Nazis in the audience, everyone stands to sing "La Marseillaise." We -- all of us -- will always have Paris.

And we must always have the Atlantic alliance. After all, apres Iraq comes the real deluge -- nation after nation embarking on nuclear weapons programs. The world, led by America and Europe, must come together to face this challenge and the challenge of our deteriorating environment. We need allies. We all need the United Nations. Even the Bush administration may now be recognizing this truth -- and how it too has contributed to the breach with our allies. The time for humility is upon us.

In the meantime, Monsieur Chirac, it is American and British men and women who will fight and die in the desert -- not the French. It has been the American threat that persuaded Hussein to permit inspectors to return to Iraq -- and that permitted France to play diplomatic games. I have always thought this war was worth fighting, and at the same time I have always feared its consequences. If things go badly for a while, the United States will need France -- if not as an ally, then at least as a silent partner.