we shouldn't expect the occupation of Iraq to be perceived as winnable

That's the fault of the current administration. The original goal - of toppling the Hussein regime - has already been met. Right now the purpose for troops to be in Iraq is to wait for stability to finally be realized. "Moral obligation" is a pretty vague justification.

The administration should come out and lay out - point by point - why it's in American and Western interests for Iraq to stabilize and be primed to accept Western ideals before troops should leave.

John McCain has come the closest to acknowledging this point by saying troops could be in Iraq "maybe 100" years.

worth it to the international community.

I think on some level Western populations and governments are aware that it is necessary to have a military presence in the Middle East and - it would appear we're moving toward - Africa. From Foreign Affairs, July/August 2005, "Europe's Angry Muslims" by Robert S. Leiken:

The footprint of Muslim immigrants in Europe is already more visible than that of the Hispanic population in the United States. Unlike the jumble of nationalities that make up the American Latino community, the Muslims of western Europe are likely to be distinct, cohesive, and bitter. In Europe, host countries that never learned to integrate newcomers collide with immigrants exceptionally retentive of their ways, producing a variant of what the French scholar Olivier Roy calls "globalized Islam": militant Islamic resentment at Western dominance, anti-imperialism exalted by revivalism.

As these conditions developed in the late 1990s, even liberal segments of the European public began to have second thoughts about immigration. Many were galled by their governments' failure to reduce or even identify the sources of insécurité (a French code word for the combination of vandalism, delinquency, and hate crimes stemming from Muslim immigrant enclaves). The state appeared unable to regulate the entry of immigrants, and society seemed unwilling to integrate them.

The uncomfortable truth is that disenfranchisement and radicalization are happening even in countries, such as the Netherlands, that have done much to accommodate Muslim immigrants. Proud of a legendary tolerance of minorities, the Netherlands welcomed tens of thousands of Muslim asylum seekers allegedly escaping persecution. Immigrants availed themselves of generous welfare and housing benefits, an affirmative-action hiring policy, and free language courses. Dutch taxpayers funded Muslim religious schools and mosques, and public television broadcast programs in Moroccan Arabic. Mohammed Bouyeri was collecting unemployment benefits when he murdered [filmmaker Theo] van Gogh.

While European populations may know it's necessary, they just can't bring themselves to actualize the fact that battling a radical element within a population is not restricted to domestic law enforcement (just as we believed prior to the 9/11 attacks).

As we're seeing with the protesting of the Olympic torch regarding Chinese policy toward Tibet, the world is far too small for any battle to be restricted to any one continent, whether it's fought with ideas or bullets.

There's a growing threat to our culture and standard of living coming from a militarized segment of a disgruntled population. Each front we're currently engaged in - Iraq, Afghanistan, Western Europe and the United States - is only one part of the larger struggle.

A realistic victory in Iraq? I think that's going to depend on what we're looking for.

In South Korea, a coup took place as recently as 1980, led by General Chun Doo-hwan (who subsequently took over as president). That's 27 years after the shooting stopped. The South Koreans didn't even have a civilian president until 1992.

I think that's the type of situation - one where the country can hold free and open elections in a democratic society which mixes traditional and Western values the current administration - and a McCain presidency - would be looking to leave Iraq in.

That's why it's worth it to the West.