You know, my former boss is working in Iraq right now. I asked him about the Vietnam comparisons. He said it was "the stupidest [bleeping] thing I've ever heard. The only thing in common with Vietnam is that the thugs who want power are trying to kill American troops. They have no safe haven, they have no superpower support, they have no support from the population at large, they're nothing like the Cong and nothing like the NVA".
Oh, and this guy was wounded at Khe Sanh. He wasn't just shooting from the hip, he has had plenty of experience in both situations.