National Security Law, 2e, is about the law governing the Canadian state's response to serious crises — that is, events that jeopardize its national security. The book approaches national security law as a system, organizing its discussion of law around five themes: structure (the mandate and roles of national security agencies); threats (aggression, terrorism, interference, proliferation, and emergencies); information (domestic and international intelligence collection, sharing, and information secrecy); response (including security screening and assessment, aviation "no fly" listings, passport revocation, immigration detention and removals, peace bonds, preventive detention, threat reduction, defensive and offensive cyber, criminal prosecutions, and use of force); and accountability (national security review).

Given the evolution of Canadian law in these areas, this second edition is a comprehensive rewrite of the first edition, first published in 2007.