The sixth edition of American National Security has been extensively rewritten to take into account the significant changes in national security policy in the past decade. Thorough revisions reflect a new strategic context and the challenges and opportunities faced by the United States in the early twenty-first century. Highlights include:• An examination of the current international environment and new factors affecting U.S. national security policy making• A discussion of the Department of Homeland Security and changes in the intelligence community• A survey of intelligence and national security, with special focus on security needs post-9/11• A review of economic security, diplomacy, terrorism, conventional warfare, counterinsurgency, military intervention, and nuclear deterrence in the changed international setting• An update of security issues in East Asia, South and Southeast Asia, the Middle East, Sub-Saharan Africa, Russia and Central Asia, and Latin America and the Caribbean• New material on globalization, transnational actors, and human securityPrevious editions have been widely used in undergraduate and graduate courses.