Judith Butler has revolutionized feminist theory and made significant contributions to the philosophy of the subject. In her recent writings, which address war and state violence, she ultimately transforms her theory of the subject into an ethics of nonviolence. Her analyses share a focus on how violence does not only begin with overt acts but is pre-structured at the level of social norms and categories that determine which lives can be perceived and recognized as worthy. This introduction clarifies the concerns and theoretical tools Butler employs to critique such "violence before violence" in various fields. Her central concepts, such as "performativity," "melancholy," and "vulnerability," are explained in relation to her ideas on gender, subjectivity, and resistance.