National Security Law: Principles and Policy, Third Edition provides a highly accessible but also comprehensive and timely supplement for students studying national security law. This concise treatise is a guide to the legal foundations and architecture that frame the exercise of key national security powers: diplomatic, intelligence, information, military, economic, and criminal. The authors explain essential legal and policy sources and principles that play an essential role in guiding the development, implementation, and review of national security policies. Central to the text is explanation of constitutional text, judicial opinions, statutes, treaties and other sources of international law, and policies. Written by a team of experts in the field, this treatise serves as a useful supplement for the substantively rich but often overwhelming National Security Law texts currently on the market. New to the Third Edition: The January 6, 2021 occupation of the U.S. Capitol New developments in executive power, cybersecurity, and artificial intelligence Benefits for instructors and students: Comprehensive overview of both the general legal framework for national security decision-making and commonly explored specific national security topics Narrative explanation of complex jurisprudential, statutory, treaty, and regulatory sources of national security law Chapters suitable as stand-alone sources for class assignments, allowing professors to substitute treatise-type treatment for primary sources where desired Incorporation of contemporary national security issues, to provide comprehensive illustrations of key laws and concepts A solid foundation for students, to facilitate focusing topical coverage on case studies and/or current events An easily accessible resource to efficiently enhance understanding of complex national security law topics Extensive use of historic examples of the impact of national security law and policy on actual national security decisions Reinforcement of the understanding of core law competencies such as federalism, separation of powers, justiciability, criminal procedures, criminal law, and statutory interpretation