There is a long history of discrimination against LGBTQ+ people in the American military and intelligence services, from vice squad stings during World War I to the “Lavender Scare” of the early Cold War through “Don’t Ask, Don’t Tell” and the Trump administration’s transgender ban. How have the rationales for anti-LGBTQ+ policies changed over time? When and why did these policies shift? What does anti-LGBTQ+ discrimination reveal about the US military, American political institutions, and broader themes in queer history? The Lavender Bans is a comprehensive account of the evolution of anti-LGBTQ+ policies from World War I to the present. Dorian Rhea Debussy—a leading expert on LGBTQ+ history in the US military—examines six distinct periods of exclusion over the course of a century, tracing continuities and changes alongside the growth of the national security state. Bringing together interdisciplinary scholarship and close analysis of archival documents, she offers new insights into the policies affecting LGBTQ+ people in the armed forces. Meticulously researched and rich in detail, The Lavender Bans sheds light on a long and troubling history—with deep contemporary relevance as exclusion of transgender people continues. It is an engaging, important, and timely book for a range of readers, including scholars, students, policy makers, military personnel, and people affected by anti-LGBTQ+ discrimination.