Neil Krishan Aggarwal's timely study finds that mental-health and biomedical professionals have created new forms of knowledge and practice in their desire to understand and fight terrorism. In the process, the state has used psychiatrists and psychologists to furnish knowledge on undesirable populations, and psychiatrists and psychologists have protected state interests. Professional interpretation, like all interpretations, is subject to cultural forces. Drawing on cultural psychiatry and medical anthropology, Aggarwal analyzes the transformation of definitions for normal and abnormal behavior in a vast array of sources: government documents, professional bioethical debates, legal motions and opinions, psychiatric and psychological scholarship, media publications, and policy briefs. Critical themes emerge on the use of mental health in awarding or denying disability to returning veterans, characterizing the confinement of Guantanamo detainees, contextualizing the actions of suicide bombers, portraying Muslim and Arab populations in psychiatric and psychological scholarship, illustrating bioethical issues in the treatment of detainees, and supplying the knowledge and practice to deradicalize terrorists. Throughout, Aggarwal explores this fascinating, troublesome transformation of mental-health science into a potential instrument of counterterrorism.