For much of the postwar era, development agencies operated as largely autonomous institutions, justified as complements to national security and diplomacy. That settlement is now unraveling. Humanitarian aid and development assistance have become increasingly entangled with security politics, amid growing skepticism about aid's purpose and effectiveness. This shift crystallized in July 2025, when the United States, under the second Trump administration, shuttered USAID and folded its remaining functions into the Department of State, echoing earlier efforts to integrate aid and foreign policy in the United Kingdom, Australia, Canada, Norway, Denmark, and New Zealand.Bureaucratic Smokescreens: Aid-Diplomacy Mergers and the Future of Foreign Policyexamines this global trend toward integrating aid and diplomacy and asks a central question: do these mergers actually advance states' foreign policy and security goals? Drawing on a comparative study of five countries over two decades, the book uses interviews with senior officials, civil servants, and activists to trace how institutional restructuring reshapes priorities, incentives, and everyday practice on the ground. Against a backdrop of rising Chinese development finance, the emergence of alternative aid donors, and a contracting foreign aid landscape,Bureaucratic Smokescreensinterrogates whether development and diplomacy can be meaningfully integrated, or whether their effectiveness depends on institutional distinction. It offers timely lessons for U.S. reform efforts and the future of foreign affairs practice.