What is the theme in Mother Night by Kurt Vonnegut?

Identity is a main theme in the book. Howard Campbell was a genuine person who loved his life and his wife. The war came along and he chose to indulge his acting skills to become someone who he wasn't. He became a master at illusion. Even his wife thought that he really believed the crazy things he said. She didn't care though because she was totally convinced that it was their life and nothing but their love mattered. He spent the whole war telling lies and he became responsible for those lies.