Garnham discusses the fundamental concepts of national security analysis. To illustrate the process by which states interact and develop security agendas, he draws on a wide variety of classic works including those of Machiavelli, Hobbes, Morgenthau, Waltz and Jervis. The paper considers the relevance of geopolitics, particularly the role of geography, culture and history, and their impact on formulating and implementing national security plans. Garnham also analyzes the problems involved in communicating and implementing security decisions.