In many cases a true war story cannot be believed. If you believe it, be skeptical. It's a question of credibility. Often the crazy stuff is true and the normal stuff isn't, because the normal stuff is necessary to make you believe the truly incredible craziness.
I was going to blog about comparing the Swift Boat Veterans' slime-fest with the former novel, but why bother? A right-wing crank has already baked up a screed that I completely disagree with. Read it, and, whenever he attempts to make an inference, draw a conclusion, or support an opinion, simply say, along with the only Marx worth quoting: Whatever it is, I'm against it.