Howard W. Campbell Jr. and Empathy in War

One of the minor characters that really sticks out in Slaughterhouse-Five is Howard W. Campbell Jr., the American-turned-Nazi. If nothing else, the image of someone clad in a cowboy hat and red/white/blue swastikas is something that's hard for most readers to forget. By including him in the novel, it seems like Vonnegut is just making a point about how the American ideals Derby talks about aren't as antithetical to fascism as people like to think. However, Campbell also appears in an earlier novel by Vonnegut, Mother Night, and his character in that book changes how we see him in Slaughterhouse-Five. 

In Mother Night, we learn that Campbell is actually a triple agent -- he broadcasts Nazi propaganda to the Americans as a way to transfer coded information to the Allies. He is actually apolitical, and has no attachment to the Nazi cause. While this might seem to dilute the message that Americans aren't as different from the Nazis as they believe, it actually really strengthens it. Knowing about Mother Night transforms Campbell from a cartoonish caricature to someone who actually really represents a person just like the other people listening to him talk. When Derby berates him, he is giving a speech about American values to someone who is actually much more important to the Allied war effort than he is. The idea that Campbell is only pretending to support this very upsetting blend of American and Nazi imagery, and is making himself seem passionate about something he personally finds ridiculous, fits very well with Vonnegut's idea of people making assumptions about the personal depth of their "enemies."

One of the moments in the book that best encapsulates this idea is the one where the German civilians watch the Americans get off the trains in Dresden. They're expecting people who are cruel and evil and dangerous, because they only think of them as their enemies in a struggle to survive. All of their problems are blamed on the Allies; it's because of the people coming out of the trains that all their male relatives are gone and there's so little food that their skin is waxy. When they see that the enemies they blame for their sallowness are just "broken human beings, like themselves," they laugh. It's a moment where all the rhetoric of war gets deflated. The only way you can convince yourself that killing other people makes sense as a way to achieve your goals is by believing that they are fundamentally different from you. Showing that even people who've convinced themselves that they're polar opposites are basically the same underneath and are just in different roles is one of the biggest things Vonnegut is trying to achieve in Slaughterhouse-Five.