In fact, some people feel that by 1972 our military goals were achieved in the sense that South Vietnam was a viable political entity. But when the democrats took control of Congress in 73, and withdrew all military and financial support for the south, the south promptly fell.
The democrats couldn't have gotten away with such an action without the steady (and untrue) stream of negative reporting.
It happened then and it could happen now, if people don't look at history, and instead get caught up the easy emotionalism of a historically low number of American casualties.
Heck , even Bin Laden gave historical precedent that the US would turn tail and run in the face of attack:
"We have seen in the last decade the decline of the American government and the weakness of the American soldier who is ready to wage Cold Wars and unprepared to fight long wars. This was proven in Beirut when the Marines fled after two explosions. It also proves they can run in less than 24 hours, and this was also repeated in Somalia. We are ready for all occasions ...
The Americans ran away from those fighters who fought and killed them, while the latter were still there. If the U.S. still thinks and brags that it still has this kind of power even after all these successive defeats in Vietnam, Beirut, Aden, and Somalia, then let them go back to those who are awaiting its return."
It was precisely this lesson of history that gave Bin Laden the guts to stage 9/11.
If the scumbag terrorists can learn the lessons of history, why can't we?
If we get too wrapped around the axle about 3 or 4 hundred casualties, and leave Iraq in the face of attack, we'll prove Bin Laden right (again)