Answer :
The theme that Vonnegut implies with Billy watching a World War 2 movie in reverse is:
What is a Theme?
The hidden message or 'central premise.' in any work of literature is what is referred to as the theme. In other words, it is that essential belief or principle that the author trying to pass across to the audience.
Some examples of themes are given below. They are:
- There is no pleasure in war
- Life is precious
Learn more about themes in the link below:
https://brainly.com/question/26965025