The administration is now caught in a dangerous dilemma, partly because its military and diplomatic tracks are out of sync and partly because of its failure to maintain America's historical leadership role in its core alliances. This is particularly distressing on the eve of a war that, if it proves to be unavoidable, would have ample justification in international rules and laws, and could be justified by existing U.N. Security Council resolutions -- without the need for a new one.

That Saddam Hussein is the most dangerous leader in the world today should hardly be in doubt after his behavior over the past 30 years. Left in power, he would undoubtedly find ways over time to rebuild his arsenal of mass destruction. The failure to finish him off in 1991 was one of the most significant errors in modern American history, no matter what the rationale offered for limiting Desert Storm to the liberation of Kuwait.

Yet the Bush administration has lost ground in recent days on virtually every front. The administration thus heads into difficult and narrow straits: It will probably have to begin a war with declining popular support not only abroad but at home. To be sure, Americans are famously patriotic and proud of their military forces, and once hostilities start, they will rally around the men and women in uniform. This was true, it should be remembered, in the initial stages of every war, including Vietnam.

But this war, no matter how justified, involves a critical gamble: Given the weak base of support it would have even at its outset, it must be quick, relatively clean and very successful or the negative consequences will be extraordinarily high. A quick war, of course, is what every American, no matter what his or her present view, must hope for -- a war of the shortest possible duration and with the lowest possible casualties on both the American and Iraqi sides, a war that does not expand into Israel or provoke domestic terrorism.

The administration is also gambling that it can accomplish its goals, not only military but political, with a strategy based primarily on America's overwhelming military advantage over Iraq. Once again, we must hope that this calculation is correct. At least in the initial military phases, it probably will be; one should never underestimate the persuasive power of power itself, as we saw with the powerful and precise use of air power in Bosnia in 1995 and Kosovo in 1999. But a policy simply based on military superiority will not in the long run be successful; even a superpower (one might say especially a superpower) needs many friends and allies to maintain its global influence.

Over the past 60 years, the United States has consistently combined its military superiority with moral and political leadership. Unfortunately, in the present case some members of the administration, and many of its most fervent outside supporters, have abandoned this tradition and acted as though complete superiority in such things as night-vision goggles (and other modern military technology) allows the United States to ignore the importance of traditional relationships. This is shortsighted; power in the world is defined by many things in addition to military strength, and no nation has shown that more clearly than the United States, whose values, economy, culture and political leadership have been essential components of its strength.

This is not to defend the behavior of some of our closest allies, whose treatment of Turkey, whose personal attacks on some of Europe's new democracies and whose strange excuses for Iraq's violations of U.N. resolutions have only made Hussein more defiant. In the simplest terms, the actions of some nations, especially France and Germany, coupled with the massive antiwar demonstrations, have undoubtedly encouraged the isolated dictator in Baghdad to think he can split the coalition and survive.

In this view Hussein is surely mistaken. But France-bashing is not a substitute for policy. The administration should not be let off the hook without questioning some of its recent tactics and strategy. After the masterful diplomacy by Secretary of State Colin Powell that produced Security Council Resolution 1441, the administration, urged on by Prime Minister Tony Blair, made the decision to seek a second resolution that would at least implicitly authorize the use of force. For Blair, this was politically important, and Washington went along with the request of its staunch ally in London. But something akin to a train wreck is now approaching, because that second resolution is unlikely to be achievable, with France and Germany (and probably Russia) leading the opposition. As a result, the U.S.-led coalition now faces the prospect of undermining its 1441 triumph with a humiliating rejection of a second resolution that was not necessary. This would leave the clear impression that any military action that follows is in violation of the Security Council's will, rather than being derived logically from the long trail of Iraqi defiance.

This seemingly technical issue constitutes another gamble that could haunt American and British policymakers unless they can pull a diplomatic miracle out of the mess. The second resolution may be achievable, but only if Hans Blix issues far more negative reports than he has so far. This is certainly possible (especially if Hussein is stupid) but the United States should never put itself in a position where a vital national interest is decided by an international civil servant or another sovereign government.

In a roughly similar situation, in 1999, the Clinton administration and our NATO allies decided to bomb Serbia (for 77 days) without even seeking U.N. approval, after it became clear that Russia would veto any proposal. This contrast with the supposedly muscular Bush administration is especially odd when one considers that Saddam Hussein is far worse than Slobodan Milosevic, and that Iraq has left a long trail of violated Security Council resolutions, while there were none on Kosovo.

In the end, sheer military force will probably succeed against a relatively weak foe. But the uncertain diplomatic process that has brought the administration to the very edge of starting a war just as international opposition to it is solidifying does not make it easy for those who have supported the goal of enforcing existing Security Council resolutions -- a goal that Washington and London risk muddling by their strange quest for that unnecessary second resolution. Nor does it bode well for the all-important post-Hussein phase, in which Washington's recently revealed plans for U.S. military control of Iraq can only spark fears that the United States will ultimately be trapped in what Winston Churchill, after the death of several British officers in Iraq in 1920, called "these thankless deserts."

The writer was U.S. ambassador to the United Nations under President Clinton.