In the upper floors of the United Nations Secretariat Building, where the organization's chief policy makers roost, the collapse of the tortured negotiations over a resolution authorizing the use of force in Iraq, and the subsequent decision of the United States and its allies to go to war nevertheless, has provoked a sense of deja vu. When I asked Shashi Tharoor, the under secretary general for communications and a U.N. lifer, whether he feared that the body was about to become irrelevant, as President Bush and other administration officials have threatened, he said: ''We've been here before. Look at Suez in 1956, look at the Congo in the early 60's, look at Kosovo in 1999'' -- all cases in which the Security Council was hamstrung by disagreements among the great powers, all accompanied by dire predictions about the body's future. ''We've seen too many special cases,'' Tharoor went on, ''and we know that it would be premature to write our own obituary.''

It would be premature -- but only in the sense that many gravely ill patients do not die. In none of those previous cases did the United States feel its own vital interests were involved; in none did it suffer so public a rebuke. And so Iraq will probably not go down as just another ''special case.'' While a debate has begun on the role of the U.N. in postwar Iraq, formulas for replacing or marginalizing the U.N. are circulating around the conservative policy circles that first drew up the case for war in Iraq in the late 90's. And the Bush administration, should it take its war on terror to other ''rogue'' or ''evil'' regimes beyond Iraq, is plainly prepared to dispense with the legitimacy conferred by a Security Council resolution.

The United States is not about to withdraw from the U.N. or ask the organization to leave New York for Paris or Brussels. But it is ready to take its problems elsewhere. David Malone, the head of the International Peace Academy and one of the U.N.'s most thoughtful and dispassionate observers, says, ''The Security Council has probably been fatally wounded in terms of its centrality to the U.S. on the use of force around the world, though it will continue to be useful to Washington for the management of conflicts on which the U.S. does not wish to lead but on which it wishes to be seen to be engaged.'' The diplomats of Turtle Bay, he says, ''don't fully comprehend the extent of the train wreck in which the Security Council has been involved.''

The U.N. was a euphoric place in November, when, after two months of hairsplitting negotiation, all 15 members of the Security Council signed Resolution 1441, authorizing a toughened inspections regime in Iraq. Only twice in its 57-year history had the council managed to solve the most fateful issues of war and peace -- in 1950, when the council authorized war in Korea (while the Soviet Union was staging a boycott of the body), and in late 1990, before the first war against Iraq. The mere fact that the Bush administration even came to the council last fall was seen as proof of how very valuable a coin the U.N.'s legitimacy remained. The press attention was positively enthralling; seasoned U.N. professionals say that they had never seen so many media trucks parked out at First Avenue and 46th Street.

The trucks are gone now, and the U.N. officials and Security Council delegates who seemed at the center of things just weeks ago now have all the time in the world to think about what went wrong. Many of the officials and delegates I spoke with said that the United States could have got its way had it behaved with greater regard for the U.N. and for the niceties of multilateralism. One U.N. political professional said to me that the debate became a referendum not on the means of disarming Iraq but on the American use of power: ''The members ended up feeling that they had to stand up to American unilateralism.'' I tried out this theory on Juan Gabriel Valdes, the ambassador from Chile, a pivotal member of the 10 ''nonpermanent'' members of the council during the Iraq debate. Valdes blamed the French for eliminating the possibility of a common ground, but also the Bush administration for what he called a ''double discourse.'' There was, he said, ''a discourse here that gave a lot of importance to the U.N., and there was a discourse in the papers based on statements from nonidentified authorities in Washington who indicated that the U.N. was just a formal and somewhat cumbersome procedure that had to be followed, but that wouldn't change the fact and the direction of American decisions.'' Valdes did not appreciate being asked to serve as a rubber stamp.

What was paramount for Valdes -- and for the Security Council as a whole -- was the preservation of the process of debate and decision. What was paramount for the Bush administration, however, was the outcome -- the disarmament of Iraq, by whatever means necessary. It may well be that an administration more inclined to play with others would have carried the day; but even a President Al Gore might well have defied the will of the council, as President Bush did, rather than accepting the consequences of his failure to win council approval.

President Jacques Chirac of France threatened to veto any resolution authorizing hostilities; the French argued (and continue to argue) that the inspections process could have led to disarmament given more time. At the council, the United States never succeeded in overcoming this claim, in large part because Hans Blix, the imperturbable and ever-so-slightly impish Swede who headed the inspection team, continued to give it credence. I visited Blix in his office recently to see whether retrospection had altered his views. Not long before, he lived at the eye of a hurricane; now he receives visitors at his leisure. Blix insisted he still does not know whether the Iraqi cooperation to which he testified before the council was, in his words, ''genuine'' or was ''designed to create illusions.'' I asked whether he believed that the issue could have been resolved if he had been given another three months, as he wished. ''I think it's unlikely this would have come to any bottom of the barrel,'' he said with his habitual caution, ''because if they didn't have any anthrax, it's difficult to prove that there is none.'' And if they did? ''With a very good tip, we would have come to it, and if you then had denial of access, it would have been decisive.'' Otherwise, he conceded, it would have been more stalemate. Blix says that one lesson he has learned is that ''if you are faced with someone who has'' chemical or biological weapons, ''and who is determined to hide them, it is very difficult to get to the bottom of that barrel.''

What drove American officials crazy about Blix was his insistence on giving Saddam Hussein points for form -- for playing along with the inspections process even while frustrating its object. Blix says that he felt that it was important to preserve his prerogatives: ''We being trustees of the Security Council have to at all times be careful about evidence, and not jump to conclusions.'' But he also seemed to be averting his eyes from the bottom of the barrel. Blix appeared to share the more or less consensual U.N. view that continued discussion is almost automatically preferable to fighting -- a view in which the belief in peace and the belief in process converge and war is always failure.

But talk can also be a form of failure when war is unavoidable. As one U.S. official familiar with the Security Council discussions told me with some frustration, ''People don't understand that we're at war.'' The events of 9/11 not only tilted American foreign policy in a strikingly martial direction; they also made Americans view the world very differently even from the way many of its chief allies do. ''No other country has the global presence and responsibility and exposure that we do,'' as this official put it.

How, then, is the United States to continue operating in a body based on consensual decision-making? Despite the ''we've been here before'' rationale being voiced, many of the officials close to Secretary General Kofi Annan are acutely conscious of this situation, as is Annan himself. Mark Malloch Brown, who runs the United Nations Development Program, says: ''We cannot continue after this crisis to believe that the world is the same. You've got to adjust your sights to reflect, or perhaps the word is 'respect,' the power of the United States.'' Edward Mortimer, Annan's chief speechwriter and an important adviser, says that the U.N. cannot simply dismiss the new American doctrine of pre-emptive warfare, though it is specifically prohibited by the U.N. Charter. The war in Iraq might come to be seen as the vindication of that doctrine, at least in carefully circumscribed cases. ''The question,'' Mortimer says, ''is 'What are the rules by which these decisions will be governed?' The Americans might not like to have any rules. But if you will agree that some rules are necessary, and that American exceptionalism cannot be the answer to all problems, then perhaps we can make headway on this problem.''

Perhaps, in other words, the Security Council can play a role in defining the new generation of threats to international peace and security, as it played a role in defining the threats of civil war and genocide in the 90's. Of course, it did a much better job of defining those threats than of countering them.

Many conservatives -- and not only conservatives -- took the position last September that the Security Council was a quagmire to be skirted, not a legitimizing body to be courted. The collapse of negotiations vindicated their position and undercut those who had argued for the U.N. route, most notably Secretary of State Colin Powell and Prime Minister Tony Blair of Britain. As policy makers and theorists begin to think about the architecture of a post-Iraq world, speculation about alternatives to the U.N. has begun to flourish. Writing in The Weekly Standard, arguably the most influential opinion journal at the White House, the computer scientist and essayist David Gelernter suggested that the U.N.'s flaws were ''woven in, not printed on.'' What's more, he declared, any organization that gave the French a veto over American actions was not to be countenanced. Gelernter proposed instead a new organization -- the ''Big Three'' -- consisting of the U.S., Britain and Russia. (Anti-Iraq-war Russia earns a spot to preclude a possible imputation of Anglophone hegemony.) Gelernter also suggested that ''democracies or aspiring democracies'' could apply to be ''junior members'' so long as they spent enough money on defense. He did not make it clear whether this might include the French.

There is no lack of other formulations. An article in the old-line conservative National Review proposed an English-speaking condominium -- no concessions wasted on the Russians here -- to be known as the Anglosphere. A more common approach calls for the creation of not-yet-dreamed-of regional alliances. Max Boot, a senior fellow at the Council on Foreign Relations and a ''liberal imperialist,'' to use one term that advocates of this view have applied to themselves, suggests an Asian NATO, for example, which could bind South Korea, Taiwan, Japan, Thailand, Australia, New Zealand and the United States -- and pointedly exclude China. Or a new version of the old Baghdad Pact assembled by Great Britain in the 50's might unite Iraq, Jordan, Egypt and the sheikdoms with the U.S. The appeal of such groupings is that the United States would be able to pursue its interests in concert with nations whose interests converge with ours, and thus ward off accusations of unilateralism. Our ''partners'' would in fact be patsies, and thus pose no threat to our interests. Boot himself unabashedly describes the proposed alliances as ''a pathetic attempt to disguise American pre-eminence.''

Candor is, of course, always refreshing. And perhaps we should say that the willingness to speak in such stunningly neocolonial language is powerful proof of American pre-eminence; such is our might that we need not dissimulate our will to supremacy. It is a symptom as well of a rampant sense of moral superiority that our go-it-alone war in Iraq will only enhance, unless it somehow, close to endgame, goes very badly astray. Lawrence Kaplan, author, with William Kristol, of ''The War Over Iraq,'' says, ''We've begun to think of ourselves as a more trustworthy universal arbiter than the U.N. itself.'' Kaplan considers this good, not bad.

Other nations, of course, might regard such new alliances of convenience as self-discrediting. As David Malone of the International Peace Academy says, ''Unless the United States is prepared to contribute to the solution of the problems of other regions and countries, those regions and countries will not long line up to serve Washington's purposes.'' In other words, what happened in the Security Council would recur in a new setting, sending us in search of new and yet more docile patsies.

The whole instant-alliance idea -- finding ''partners'' where we need them when we need them -- seems faintly preposterous. But it is good to remember that the idea of invading Iraq -- and doing so unilaterally, if necessary -- seemed outlandish when a group of foreign-policy intellectuals and former officeholders proposed it in a letter to President Clinton in early 1998. The group, organized as the Project for the New American Century, included Donald Rumsfeld, Richard Perle and Paul Wolfowitz. A number of figures in the Bush National Security Council, as well as the State Department, are thinking about the question of a new international order. And the Project for the New American Century remains an important player in nascent discussions of a new architecture. Gary Schmitt, the project's director, observes that NATO might be a better instrument for American policy than the Security Council, as long as the organization abandons the requirement of consensus in favor of a ''supermajority,'' thus preventing France and Germany from frustrating American designs.

Whether any of these institutions come into being, or are reformed to suit our purposes, there can be no question that this administration will be looking for alternative means of demonstrating that it has company in its foreign-policy ventures. The United States is already accustomed to ''forum shopping,'' as when we sought the NATO aegis for the bombing of Kosovo in 1999. The new wrinkle in coming years is likely to be the ad hoc, rather than formal, alliance -- the ''coalition of the willing.'' The Security Council has in the past authorized such coalitions to act, as it did with the largely Australian force that intervened in East Timor, also in 1999. But don't count on the United States' waiting for U.N. approval.

There is a theory that the United States needs the U.N. as much as the other way around. As the one global actor, the U.S. has the greatest possible stake in the solution of global problems like AIDS, refugees and of course terrorism -- problems that require the mobilization of the whole world, and thus the engagement of the U.N. Ambassador Valdes of Chile says that he recites this mantra to himself all the time, even as he sees the U.S. drifting further from the U.N. Certainly the U.S. will continue to find the U.N. a useful forum for the solution, or at least the discussion, of all sorts of problems. The big question is whether these problems include first-order issues of peace and security.

At the moment, the U.N. is helplessly awaiting the next signal from Washington. That signal will involve the reconstruction of Iraq, should the coalition forces ultimately succeed in ousting Saddam and his regime. Before hostilities even began, Kofi Annan formed an ''Iraq steering group,'' which produced a document laying out plans for a United Nations ''assistance mission'' in Iraq. U.N. professionals have more experience with nation-building than anyone else in the world, though with varying levels of success. No one in the secretariat expects, or for that matter wants, to hoist a U.N. flag over liberated Iraq. But Annan and his chief aides say they are hoping to play the same kind of role as the U.N. now does in Afghanistan, where Lakhdar Brahimi, a representative of the secretary general, helped shape the Afghan government and continues to adjudicate among the various parties as well as acting as a buffer between them and the American military.

The politics of this question are fierce. Tony Blair, desperate to restore his multilateral bona fides with his own citizens and with the leaders of other European nations, has lobbied for the largest possible U.N. role; Secretary Powell has also been pushing, though less strenuously. On the other hand, administration hawks, whose case has been strengthened by the council's failure to adopt a second resolution, are determined that the U.S. run Iraq by itself before handing off to Iraqis of its choosing after several months. The Pentagon is already assembling a government in waiting consisting of retired American diplomats and soldiers. Late last month, Condoleezza Rice, the national security adviser, visited Annan to say that the administration was eager for the U.N. to play a role in Iraq, but that the role would be limited to humanitarian relief. A senior administration official parses the question as follows: ''We're not looking at Afghanistan redux. I think we're looking at something more of a division of labor, where the coalition retains the security function, where the U.N. and international agencies assume a lead role on the humanitarian side and where there's a division of labor or a sharing of responsibility on the political and economic side among governments, the U.N. and, increasingly, Iraqis.''

Beyond the reluctance of key Bush administration officials to give the U.N. a prominent role in any postwar Iraq, there is the question of just how the U.N. can authorize its own involvement. Any U.N. mission beyond humanitarian aid will require a Security Council resolution. The French and the Russians might block any new resolution implying ''retroactive legitimation'' of the war. And if the Bush administration sees a battle looming, it may sheer off altogether.

The truth is, we are still figuring out what the U.N., and especially the Security Council, is for in the era of American hyper-puissance, as the French have it. It may very well be true that the United States simply does not need the United Nations anymore; you might say that it almost never has. The U.S. does, however, need other countries; and the other countries we need believe in the U.N. whether we do or not. As Richard Haass, the State Department's director of policy planning, puts it, ''To the extent we need multilateralism, we're going to have to live with the reality that the U.N. will be the multilateral institution for just about everybody else.'' Then again, Haass is about to leave the Bush administration to become the head of the Council on Foreign Relations. He may not be leaving behind very many people who agree with him.

James Traub, a contributing writer for The Times Magazine, has reported often from the United Nations.

Copyright 2003 The New York Times Company. Reprinted from The New York Times Sunday Magazine of April 13, 2003.