Stakes in Iraq are high, but how high?

Time and again, President Bush has insisted that his administration will settle for nothing less than "complete victory" in Iraq.

Likewise, prominent members of Congress, such as Sens. John McCain (R) and Joseph Lieberman (D), have said America "cannot afford to lose."

Yet as a new Iraqi government inches toward taking more responsibility, what the United States will accept as victory is much more than a rhetorical exercise to reassure the American public about the course of the war. Rather, defining victory serves as a measuring stick of when and if the US should begin to disengage.

The base line for success is only a relatively stable government that denies terrorists a haven, analysts say. Yet in a polarized Congress and country pulled between the extremes of staying the course at any cost and withdrawing as soon as possible, there has been little dialogue about what the most realistic waymarks might be, or what America should do when Iraq does - or does not - meet them.

"The debate has been far too ideological," says Anthony Cordesman of the Center for Strategic and International Studies here. "It doesn't prepare US citizens for all the contingencies when we might have to leave. It has been far too unwilling to ask: What really happens next?"

In his speeches, Mr. Bush has refused even to consider the possibility of failure - such as a political collapse, a deepening of civil strife, or the disintegration of the Iraqi Army. In many respects, positive pronouncements are natural - and not altogether unwise. "The president shouldn't go out and talk about all the ways we can lose," says Dr. Cordesman.

Yet the lack of greater sophistication on either side of the Iraq discussion risks simplifying the stakes, he and others say - casting the conflict as either a hinge of 21st-century history or a foolish mistake best abandoned. Between those two opposites, there are a multitude of opinions. Most experts largely agree with the idea that Iraq is of fundamental importance to US security, both as a nexus for terrorism and as a linchpin of the petroleum economy. Yet many cast success more narrowly than Bush's vision of an Iraq "that will serve as a model of freedom for the Middle East."

"The American people will refer to this war as being won if we prevent the export of very dangerous weapons [from Iraq] and create some sort of nonthreatening state," says retired Gen. Robert Scales.

What has largely gone unanswered, though, is the question of what America should do if the situation in Iraq deteriorates further. For his part, Cordesman looks for an answer in recent history. During the 1960s, Vietnam was perceived to be a vital bulwark against the menace of the day - the spread of communism. With evident resolve President Johnson declared in 1965: "We will not be defeated. We will not grow tired. We will not withdraw, either openly or under the cloak of a meaningless agreement."

Yet the US did withdraw, communism did claim another country - and nothing happened to American security. Cordesman cites Vietnam as an example of how "limited wars" must have limited objectives - and that America must be ready to step back if the price of winning becomes too high.

"If Iraq falls apart, that's a defeat," he says. "There's not a lot you can do by sending in more American troops."

This not to suggest that America should pull out - "It's a war we should win if we possibly can," he says - but rather it is an acknowledgment that policymakers must prepare for every eventuality. And in some cases, losing in Iraq might make more strategic sense than blindly staying the course at all costs.

"If the country moves into a major civil war, we can't afford to take sides," he says.

It is a controversial notion, even among analysts. And to be sure, Iraq presents different challenges than did Vietnam. "In Vietnam, you always had an alternate government," says Dan Byman of the Brookings Institution here, noting that when the US-backed South Vietnamese government fell, North Vietnam assumed control. If Iraq's government falls, he adds, "chaos brings a different set of circumstances."

A lawless Iraq could become a much greater threat to the US than Afghanistan ever was as a nest for terrorist training and activity. Or it could destabilize the world's foremost oil- producing region. "Losing in Iraq has considerable costs," says Dr. Byman.

Yet he also suggests that the notion of winning and losing in Iraq has been overly simplified. It is probable that at some point "complete victory" might come into conflict with pragmatism, as America wrestles with when to cede its authority to a government still seeking its way.

Says Byman: "How satisfied are you with progress and not with absolutes?"