If the United States ultimately follows through on its growing threats to sidestep the United Nations and launch a war with Iraq, some of the immediate consequences are easy to sketch.
The war would be more expensive for Americans, in terms of tax dollars and likely casualties, even if the effort included some help from a "coalition of the willing." The US would also have a more dominant role in forging a postwar Iraq.
But a Middle East war in which the US goes it largely alone, with Britain, could have wider implications for the global community and the rules that have helped to guide the world on the use of force for the past 50 years, some experts say.
"This case has the potential to be a historic turning point, [one that could] really strike a blow to the deeper order that's been in place since World War II," says Charles Kupchan, an international relations expert at Georgetown University in Washington.
In fact, while the Bush administration has sought to put the focus on UN impotence in dealing with "rogue states," a likely outcome in this case would be greater global attention on the exercise of American power.
Other countries, chafing at the predominant role of American power in the world today, already appear to be trying to develop a counterbalance. The French, who refer to the US as the world's "hyperpower," hope to develop a "European stance" for next week's crucial UN meetings on the Iraqi crisis.
With world opinion lining up in opposition to a war, the French are having some success in their efforts to forge a counterweight to US power. Under pressure from France and Germany, NATO on Wednesday put off a decision on a US request for alliance assistance in the event of a war with Iraq. On Monday, UN weapons inspectors deliver a report on Iraqi cooperation with their work to the UN Security Council. Then on Wednesday the council will debate the report - with France and Russia arguing the inspections need more time and only the council can make a decision for war.
In this context, a US war would also prompt deep delving into why the UN model has failed at the job of guiding the use of force in the world.
This doesn't mean there is no potential upside for America's position in the world. The view of some policymakers within the Bush administration is that a quick war that ousts Iraqi leader Saddam Hussein and allows for the democratization of Iraq will bring new stability to a volatile region and enhance the chances for American-style ideals to spread in the Middle East. For these officials, it is a resistance to enhanced US prestige that partly motivates countries that would oppose a US war.
Few experts envision a scenario under which a war with Iraq leads to a rewriting and reinforcement of the international rules on the use of force.
"The international system the world set up after World War II to apply the rule of law to the use of force is collapsing, and the use of force against Iraq would highlight that collapse as nothing else," says Michael Glennon, a professor of international law at the Fletcher School of Law and Diplomacy at Tufts University in Somerville, Mass. "But if a war is quick and successful for the US, chances are there won't be a groundswell of support for formulating a new set of rules."
Of course, any war with Iraq was destined to be an American-commanded and predominantely US-fought intervention under any circumstances. But it is the global perception of whether it is a US fighting solo or with the backing of the international community that will matter, experts say.
As concerned as other countries may be about America's exercise of power, they are unlikely to take actions that would turn the US further from the United Nations. The surprise appearance of the North Korean nuclear arms issue on the international stage offers a case in point.
Disagreement with the US on Iraq is not likely to prompt the world to rebuff American efforts to take the Korean question to the Security Council, most observers say.
"We're confusing people at home and around the world" with the two very different tacks taken on Iraq and North Korea, says Lawrence Korb, a former Pentagon official under President Reagan and now an international relations specialist at the Council on Foreign Relations in New York. "When it's not clear what you're doing it's harder to get people to go along with you. But that doesn't mean they won't when they perceive it's in their interest."
In Seoul, South Korea, Wednesday, Undersecretary of State for arms control and international security John Bolton said he expects to have lined up international support for taking up the North Korean arms issue within the Security Council by the end of the week. That stance contrasts starkly with what some US allies and partners see as US "impatience" with the UN process in Iraq.
French Foreign Minister Dominique de Villepin said this week that the US moving unilaterally on war with Iraq could have an adverse impact on international cooperation over other international issues, including the North Korean crisis. But the international community is not likely to push it further into acting alone by snubbing its willingness to act multilaterally on North Korea.
Countries like France and Germany, which assumes the presidency of the Security Council in February, "are in a double bind," says Fletcher's Mr. Glennon. "They see they have to show some dissatisfaction with the US, but at the same time if they act vindictively, they risk [making] the US less likely to work with the Security Council."
Security Council members are able to "compartmentalize" different issues and work with the US on one, even when in dispute with it over another, says Paul Taylor, director of the European Institute at the London School of Economics and Political Science.
What is likely to color the world's ability to work with the US on international issues, Mr. Taylor says, is a "growing distrust" among some European countries of US intentions.
"All the concerns that have built up over the Bush strategic doctrine [of preemption] and unilateralism come to a head in Iraq," he says. "It feeds this perception that Bush was intent on fighting a war with Iraq even before Sept. 11," and that the US is simply interested in an international cover for its military intervention, he adds.
Georgetown's Mr. Kupchan, author of the recently published "The End of the American Era," says unilateral US action would very likely cause countries that have generally welcomed the exercise of US power in their regions to turn up resistance to a US presence. This is already occurring in South Korea, he says, and could gain steam in Japan, Europe, and the Middle East - the latter being the very region the Bush administration insists would be opened to a wave of democracy and development in the aftermath of a war to oust Hussein.