This text grew from the need to explain the U.S. national security system to working graduate students in Washington, DC. It assumes no prerequisite knowledge, only an interest in national security. It begins by providing a foundation in international relations theory and concepts, and continues with the unique American political view, including war powers. It reviews the Cold War and post-Cold War national security strategies. Each government organization with a role in national security is reviewed, with special emphasis on the National Security Council. The text concludes with a review of prominent studies calling for reform of the national security system.