When millions of Syrians fled civil war after 2011, international donors and humanitarian organizations mobilized to provide assistance to neighboring countries. Focusing on Jordan—one of the world’s second-largest refugee hosting states— Disease and Diplomacy investigates how medical aid to refugees operates as an instrument of diplomacy and control within the global refugee system. It argues that health, far from being an apolitical humanitarian good, is a bargaining tool that states commodify to extract resources and concessions. Drawing on years of field research, interviews, and policy analysis, the book shows how the Jordanian government, international donors, and humanitarian agencies turned healthcare for refugees into a tool for negotiating power, resources, and responsibility. In these cases, refugees, caught within these negotiations, often found their access to care determined not by medical need, but by political calculation. Developing the concept of the weaponization of medical aid, the book extends theories of migration diplomacy and refugee rentierism to show how global power dynamics shape who receives healthcare. The analysis identifies a self-reinforcing “crisis loop” that privileges short-term, highly visible responses while neglecting chronic and long-term needs. Disease and Diplomacy advances an interdisciplinary framework for understanding how humanitarian practices reinforce global inequalities and argues for more equitable approaches to refugee health and responsibility-sharing in the international system.