Dr. Gus Martin’s Understanding Homeland Security, Second Edition is a thoroughly updated textbook offering much-needed insight into the complex nature of issues addressed by the homeland security enterprise. This comprehensive textbook addresses such subject areas as emergency management, terrorism, criminal justice administration, intelligence, armed conflict, and social environments. Martin’s pedagogical approach is designed to stimulate critical thinking in readers, allowing them to not only comprehend the fundamentals, but also evolve with the very dynamic nature of homeland security. The Second Edition introduces readers to homeland security in the modern era, focusing particularly on the post–September 11, 2001 world. Reviewing theories, agency missions, laws and regulations governing the homeland security enterprise, this book keeps readers on the forefront of homeland security.