I apologize if I sound like an ass here but at this point you have me confused because almost all of what you posted didn't seem to contradict what I had said. For that matter I cited source material too that you said was wrong too. I didn't experience the Vietnam war personally so I can't vouch for it as first hand but it sounds like you have a problem with not just my view but the source material too.
I took a quick look at the stats and you are correct that individually the US in WWII lost more men, 407K, than the Union or Confederate individually but the total of the US deaths of both sides was greater than the WWII number, 620K to 700K, (http://www.civilwarhome.com/casualties.htm) I don't think that comparing allies deaths would apply as the battles were fought on their own countries, particularly Soviet deaths as the battles reached far into their territory. I will agree with your general point that the US has been willing to sustain large casualties in a foreign war but again the context of what was going on Globally was far different than now. In Japan and Germany we were facing the most technologically advanced military powers at the time that had shown they could defeat other major countries. Iraq could hardly do that and withered like a kleenex in a bonfire just trying to hold onto tiny Kuwait. As I said earlier with good leadership the US populace might support taking a lot of casualties in a foreign war but the problem with this war is that the Admin. has failed to show that kind of leadership. You could blame it on political opponents but even FDR faced political opponents regarding whether we should enter the war and many resisted even Lend Lease program. This is a point where I think both you and Sam are correct. There were times that the US withheld bombing Hanoi but the NVA and VC were well dug in. My own understanding (and I suspect Rage will seek to correct me) is that the NVA didn't try to field heavy weaponry that much against us knowing that that was hopeless but kept it hidden in reserve.
NOt to mention that the US population in 1960 was about 30 million - in other words 25% of what is was in 1940. The scale of national slaughter in the civil war easily dwarfs any war in US history by any rational definition- it's not even debatable.
The media is the true cause of all the problems in Iraq -- way to nail that one on the head SM. No other issues at all...
If we had Chancellor von Basso and Field Marshal StupidM running Iraq strategy, the Iraq war would be over in a second. All we have to do is destroy the insurgents' fighter planes and helicopters and disable their radar systems. Couple that with a classic cavalry square followed by an arrowhead ripping pincer movement and bam-o.
Don't forget to throw in a fine pair of Clipper Ships and a Corvette to control the sea my friend. YARRRRRRR
Now you are closer to the truth. This is an example of what I was talking about. Your source material was not wrong. It was right at certain point in time or situation. Things changed. You don't have to read and understand everything except if you were going to make a judgment, you needed more information.