The types of destruction caused by war in Slaughterhouse-Five are physical and psychological.
The novel describes the physical toll war takes. Description of the destruction caused by the bombing of Dresden is explicit in the novel, as are the haggard states of the suffering soldiers--on both sides. And humans have no control over whether or not they suffer. Good soldiers die and suffer the same as poor soldiers. Billy is a terrible soldier, for instance, and suffers because of it. But he is just as likely to have suffered had he been a good soldier, as the execution of Edgar Derby demonstrates.
Billy suffers from more than physical hardship as a result of the war, however. His mind is fragmented, as the collage-like structure of the narrative reveals. He is passive in the face of war--how else can one be? He has no control of his fate. The only time he is active in the novel is when he decides to tell the world about Tralfalmadore, etc., near the end of his life. Billy can't face the horrible memories of war, so he escapes however he can.
After all, what can one do in the face of human bone meal and corpse mines?