Catastrophic Diplomacy offers a sweeping history of US foreign disaster assistance, highlighting its centrality to twentieth-century US foreign relations. Spanning over seventy years, from the dawn of the twentieth century to the mid-1970s, it examines how the US government, US military, and their partners in the American voluntary sector responded to major catastrophes around the world. Focusing on US responses to sudden disasters caused by earthquakes, tropical storms, and floods-crises commonly known as “natural disasters”-historian Julia F. Irwin highlights the complex and messy politics of emergency humanitarian relief. Deftly weaving together diplomatic, environmental, military, and humanitarian histories, Irwin tracks the rise of US disaster aid as a tool of foreign policy, showing how and why the US foreign policy establishment first began contributing aid to survivors of international catastrophes. While the book focuses mainly on bilateral assistance efforts, it also assesses the broader international context in which the US government and its auxiliaries operated, situating their humanitarian responses against the aid efforts of other nations, empires, and international organizations. At its most fundamental level, Catastrophic Diplomacy demonstrates the importance of international disaster assistance-and humanitarian aid more broadly-to US foreign affairs.