Poo-tee-weet?

Before the story started, Vonnegut warned the reader that his novel would begin with "Listen: Billy Pilgrim has become unstuck in time" and end with "poo-tee-weet?" In the introduction chapter, Vonnegut said that after such destruction like Dresden the only thing that can be said is by the birds. The end of the novel shows Billy and his war friends finally leaving the destruction of war and Dresden behind. It ends by saying that he could hear the birds saying poo-tee-weet. This is the authors way of leaving the antiwar ideals to the reader to decide. He described the situation and all that could be said was poo-tee-weet.