The Light at the End of the Tunnel......is the Quagmire Express, coming right atcha!
There are so many ridiculous parts to the Preznit's Vietnam analogy that I can't hit them all. Let's start with just one - that the Vietnamese and others in Southeast Asia would have been better off if the US hadn't backed out of the region when we did. Chimpy refers to 'boat people' and 'the killing fields' and re-education camps - all were bad things (let's not forget that it was the Vietnamese that shut down the Khmer Rouge, but anyway...). What he does NOT mention is the number of Vietnamese killed during the course of the Vietnam War, numbers that one would expect would continue to grow had the fighting continued due to the continued presence of the US. There is an appropriate focus on the almost 60,000 US servicemen killed but very little mention of the vast numbers of Vietnamese (both soldiers, insurgents and civilians) killed from 1959 to 1975 (on top of the many killed while fighting the French colonial powers in the 40s and 50s). As I've looked around the web, the numbers range pretty widely, but it appears that somewhere between 2 million and 4 million Vietnamese (both North and South) were killed and as many as another 3 million affected by Agent Orange. How would those numbers have changed had we stayed another 5 years? 10 years?
And what does that say about Iraq? Your guess is as good as mine. If we stay, we can be pretty sure of continued sectarian violence (doesn't that pretty much mean civil war?) and high casualties among the civilian population. How does that change if we leave? Might mean casualties go up without US troops providing security (since it seems that Iraqi troops and police are as likely to be participants as they are to prevent violence), might mean Iraq fragments into three distinct countries (which might happen anyway), might mean the suicide bombers that our presence there has created might not be quite so incented and casualty rates for civilians might go down.
That's the problem with badly applied historical analogies - they really don't tell us anything useful.