In 2006, the United States Department of Defense for the first time authorized the use of FDA-approved psychiatric medications in the physical and tactical spaces of military operations including active combat. This policy change overturned a century of military psychiatry orthodoxy, which prioritized non-pathologizing, non-medication treatment for combat stress. Amid an ongoing global war, the US military embraced psychopharmacy as a radical and untested tool for keeping soldiers on the counterinsurgency battlefield and deploying them again and again, even with psychiatric diagnoses. Through powerful storytelling and original analysis, Stabilizing Empire uncovers a quiet revolution during the war on terror: the pharmaceuticalization of battlefield mental health care.