Andy, The major difference is the scale of killing. If ground troops are to move into a major city the civilian death toll will be enormous.
I know some guys who were in the military during the US invasion of Panama. The stuff in the news about mass graves of civilians dug by the US military is true. I've been told by first hand sources that the US government did not want a large US troop death toll. so if US troops encountered any sniper fire they would simply call in an artillery attack on those city blocks and kill everyone who lived there.
Baghdad has a much greater population density so in a simliar situation the number of civilian deaths is potentially exponentially greater. If US troops go in there it will be a bloodbath. They will keep the western media out as much as possible, but eyewitnesses will report what they have seen to Arab news organizations, where it will be reported. So once again the potential for civilian death is dramatically increased as the likelihood of fighting spreading into other countries in the region increases (due to the uproar over how callous US military policy is toward the killing of innocent bystanders).
It's late and I hope I am being clear. They can continue to do what they are doing and keep it fairly well hidden (at least here in the US). The reason they are debating the topic in public is the intended killing is on such a larger scale.
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"Eat a fucking cock." - attitudechicka