It's simple Burbank. You LIKE the Vietnam one because it's simple shorthand that fits your agenda. Vietname was the war most everybody can agree was bad news. No matter that Vietnam has become code for "a bad war you can't win, and even if you win it, it won't really be winning" and that Iraq probably deserves to be known for being it's own mess entirely, unique and special that it is.
The Nazi, Hitler, Appeasement one just makes you uncomfortable. Especially when it's applied with relevant context not as an analogy but an extension of the same bigoted fascist mindset.
I agree, the Holocaust references are a bit much (remember, I think Mel Brooks has even done damage in that regard), but The Leftists adopted turnspeak years ago, and you didn't say shit. You just don't like Bush... but what else is new.
See, so since it's not just an analogy, you're going to need some factual reason to dismiss it.