Book excerpt: Homeland security is a massive enterprise that gets larger by the moment. What was once mostly a TSA/aviation concern has evolved into a multidimensional operation covering a broad array of disciplines. These include critical infrastructure protection, border security, transportation security, intelligence and counterterrorism, emergency management, immigration and naturalization, and public health. Homeland Security: An Introduction to Principles and Practice, Second Edition provides students and practitioners alike with the latest developments on the makeup, organization, and strategic mission of the Department of Homeland Security (DHS). This new edition is fully updated with new laws, regulations, and strategies that reflect changes and developments over the last several years. The book offers unique insights into the various roles of multi-jurisdictional agencies and stakeholders at all levels of government—including law enforcement, the military, the intelligence community, emergency managers, and the private sector. Coverage includes: The history of security threats in the American experience, the events leading up to 9/11, and the formation and evolution of the DHS The legal basis and foundation for the DHS The nature of risk and threat Training and preparatory exercises for homeland security professionals How states and localities can work compatibly with federal policy makers Federal Emergency Management Agency (FEMA) in both the pre- and post-9/11 and post-Katrina world The agencies and entities entrusted with intelligence analysis Issues surrounding border security, immigration, and U.S. citizenship Homeland security practice in the airline, maritime, and mass transit industries—including national, regional, and local rail systems The interplay between public health and homeland security Each chapter contains extensive pedagogy, including learning objectives, informative sidebars, chapter summaries, end-of-chapter questions, web links, and references to aid in comprehension and retention. Homeland Security: An Introduction to Principles and Practice, Second Edition is the only book to provide an objective, balanced perspective on each of the core components that comprise the DHS’s mission and the priorities and challenges that federal and state government agencies continue to face.