The fifth edition of US National Security retains the structure and approach that have made this text so successful, but it has been revised and updated throughout to reflect the challenges faced by the Obama administration. The choices necessary in an increasingly budget-constrained environment, the broader range of national security issues, and the evolving nature of counterinsurgency doctrine and practice are among the currents that inform the authors' clear presentation and appraisal of US security interests, politics, and processes.