NEW YORK With U.S. troops massing against Iraq, Americans are apprehensive and divided. The polls show us still torn between containment and war, between the instinct to give it time and the yearning to get it done. We worry about civilian carnage, American casualties and terrorist reprisals, about further shocks to a shaken economy, about being a nation alone. The Pentagon is ordering body bags by the thousands.

President George W. Bush has enlarged the war agenda: we are not just eliminating a threat, we are delivering a promise of democracy to a region steeped in tyranny. Many, though, remain suspicious of our motives. "No Blood for Oil," the protest placards insist, and others mutter that this is somehow, too much, about Israel. The question of what comes after war has revived our longstanding fear of getting bogged down in unfriendly places; there is talk that we might "win the war and lose the peace."

Colin Powell, after trying to slow the march to war, has fallen loyally into step with his commander in chief. But the world, whose collaboration we crave, is in no hurry. The Germans are paralyzed by war angst. The French, deeply invested in Saddam Hussein and always happy to tweak the Americans, are maddening. Democrats are straining for a way to be patriots without forfeiting independent judgment. The Vatican and Hollywood are on their respective high horses. Saddam watches it all on CNN, and assures us we will be bloodily humbled.

Ah, the memories. The paragraphs above are constructed from coverage of America's mood in the winter of 1991. Reading the clippings makes me wonder if George Santayana was only half right: even those who remember history are condemned to repeat it.

A little time in the archives is a reminder that this war is in many respects a continuation of that war. We are calling to account a tyrant who has flouted the terms of his surrender. It's not just that we have been here before; technically, we never left.

Another thing that strikes you when you revisit the Gulf War is that much of what we anticipate with such confidence today will turn out to be wrong. The pessimists had to admit, in the end, that the victory was easy. The idealists had to admit it was also unfinished - as the abandoned Kurdish resistance, Iraq's miserable inmates and those yet-to-be-democratized Kuwaitis can testify. Evicting Saddam from Iraq will probably be more difficult than evicting him from Kuwait, but we won't know until we try. The promise of a Middle Eastern renaissance may be a romantic fantasy, but we won't know that, either, unless we try.

What leaps out most powerfully, comparing then and now, is the intense fear that this war will admit new horrors into our own lives. In the reporting of 1991, you find occasional mentions of a possible terrorist backlash, but they are almost incidental to the debate. Americans then, four years before Oklahoma City, were mostly innocent on the subject of terror.

For obvious reasons, that danger is no longer in the realm of conjecture. This time, when the CIA predicts that invading Iraq will provoke new assaults on our cities, Americans know in our stomachs what that means.

These anxieties are amplified by doubts about our leader. Some Americans question Bush's very legitimacy as president and as commander. I doubt that anyone referred to the first President Bush as a "chicken hawk," or to his administration as a "junta." These are insults, not arguments, but they add heat to an opposition that was pretty lukewarm last time.

Americans' uncertainty about whether we are in safe hands has been compounded by Bush's own leadership. We have the skewed priorities of an administration that declines to call for any sacrifice, even from those who can best afford it. We have Bush's manhandling of our partners in security - beginning with the gratuitous decision to take a project that could have been framed as the enforcement of United Nations resolutions and elevate it to an America-first doctrine of pre-emptive power. We have the loopy alarums of the Department of Homeland Security, which is prescribing duct tape one day and Prozac the next.

What most animates our anxiety, I think, is the fear that war will backfire. Most people did not imagine themselves anywhere near the front line in 1991. Now the front line is where we live, and we are afraid. .We fear that in pursuing Iraq, we are diverting money and attention from the hunt for Al Qaeda, and from the fortification of America.

We fear that if we attack Iraq, Saddam will have every reason to arm the terrorist brigades against us, which we have no evidence he has done so far.

We fear that every civilian killed by American bombs will inflame the hatred that much of the Islamic world already feels for us. We fear that if we occupy Arab land, recruits will flock to the martyr brigades.

And we fear that fracturing our most vital alliances will leave us to face our legions of new enemies alone. .Those of us who have come to believe that Saddam should be ousted must concede that those dangers are real - and they are, to use the most abused adjective of this debate, "imminent." These fearsome possibilities can be minimized, but in the short run it is entirely possible that attacking Iraq makes us less safe.

The problem is, peace does not eliminate the risks. At best, it postpones them. At worst, it allows small nightmares to grow into big ones.

First, Al Qaeda terrorists do not need the pretext of an Iraq war to come after us. They will attack us, unprovoked, repeatedly and in as spectacular a fashion as their lethal ingenuity allows, regardless of what we do in Iraq. We know this because they have done it.

Second, any containment regime will eventually unravel, because the outside world does not have the resolve to maintain it and because a dictator with oil has the marketplace on his side. We know this too because we have been through it. Saddam is likely to outlast our inspections and our sanctions, and certain to return to the production of the horrible weapons he sees as essential to his personal mythology.

Third, any clampdown sufficiently draconian to reassure us would amount to a United Nations occupation, which would be a grave humiliation to Saddam. It seems to me a year or two of this would be as likely to stimulate eventual vengeance as war itself.

Fourth, we come to the murky relationship between the terrorist state and stateless terrorism. The administration has surely strained our trust hyping the connections between Saddam and Al Qaeda, but skeptics have just as badly understated the mutual interests of these two thugs. Yes, Saddam came to power as a secular, pan-Arab fundamentalist and Osama bin Laden as a virulent Islamic extremist. Stalin and Hitler were ideologically incompatible, too. But all these figures are at heart power-hungry, history-seeking opportunists. None have a record of being terribly fastidious about doctrine when it stands in the way of expedience.

No one has stated this quite as baldly as bin Laden himself, in his latest taped screed. The Iraqi leadership may consist of "infidels" and ungodly "socialists," he said, but "it does no harm in these circumstances that the interests of Muslims and socialists crisscross in the fighting against the crusaders." Is it really so hard to imagine that the inventive evil of bin Laden and the ruthless ambition of Saddam will find common purpose? Do we want to find out?

And finally, there is the price America would pay for backing down now with Saddam still in place.

Hawks within the administration have been dreading the possibility that Saddam would make a good show of capitulating. Faced with a serious UN ultimatum, they worried, he would "discover" the missing toxins and offer them up for destruction. France would lead a new campaign to lift economic sanctions - keeping a skeleton crew of inspectors on hand. At this point Bush would face enormous pressure to declare victory and bring home the troops. Saddam would remain smugly in place, biding his time. America's credibility would be severely compromised.

The peace camp will dismiss this as schoolyard machismo. But credibility is the friend of peace, because enemies who know you are as good as your word are less likely to test it. Which, as much as any other reason, is why we can count on going to war.

The protests last weekend and the anguish in the polls represent something genuine, a force that Bush will have to reckon with and that some of his foreign allies may not survive. But what the anti-war camp offers is a false sense of security. In the short run, war is perilous. But in the long run peace can be a killer, too.