Mother Night by Kurt Vonnegut Jr.

Whilst awaiting trial for war crimes in an Israeli prison, Howard W. Campbell Jr sets down his memoirs on an old German typewriter. He has used such a typewriter before, when he worked as a Nazi propagandist under Goebbels. Though that was before he agreed to become a spy for US military. Is Howard guilty? Can a black or white verdict ever be reached in a world that's a gazillion shades of grey?