Drawing on her expertise in both comparative politics and international relations and on her experience as a former public official, Lancaster provides five in-depth case studies—the United States, Japan, France, Germany, and Denmark—that demonstrate how domestic politics and international pressures combine to shape how and why donor governments give aid. In doing so, she explores the impact on foreign aid of political institutions, interest groups, and the ways governments organize their giving. Her findings provide essential insight for scholars of international relations and comparative politics, as well as anyone involved with foreign aid or foreign policy.