A new textbook exploring selected national security law issues, focusing on the choices between liberty and security and law's role as a tool or constraint on national security policy. Written for readers interested in national security law and policy, but who may not have prior experience studying the areas of law that comprise national security law such as constitutional, international, and criminal law. The authors present fascinating problems and dilemmas, while clearly explaining complicated legal material. The text explores the constitutional separation of national security powers, constitutionally guaranteed liberties, international law, counterterrorism law, intelligence operations, homeland security, and more!