I don't know what you are trying to say. It sounds like you've missed the point of the quote, which is understandable as it's not very transparent from that one sentence. To put the Vonnegut quote in fuller context:
"One of the great American tragedies is to have participated in a just war. It’s been possible for politicians and movie-makers to encourage us we’re always good guys. The Second World War absolutely had to be fought. I wouldn’t have missed it for the world. But we never talk about the people we kill. This is never spoken of."
The point of the quote is that the US participation in just wars like WWII has given the US government a free pass in a vast number of other conflicts where it's behaviour has been shameful, as well as when it comes to the behaviour in specific instances in just wars. And this has happened to a great extent with the intelligence agencies too.
