What is the theme in Watch on the Rhine by Lillian Hellman?

Duty and responsibility is another theme in the play. The courageous actions of several of the characters in the play stem from their devotion to duty and responsibility. Kurt feels that he has a duty to his countrymen, whom he has seen murdered by the Nazis, and to all who suffer under fascism. When Fanny implores him to let someone else take the dangerous responsibility of carrying on the fight, someone without a family, he tells her that anyone could find a reason not to commit oneself to the cause.