National security is the measures taken by a state to ensure its survival and safety. National Security includes the deterrence of attack, from within and without, as well as the protection and well-being of citizens.

Measures taken to ensure national security include:

• the maintenance of armed forces
• civil defense measures and emergency preparedness
• attempts to create resilience and redundancy in national infrastructure
• the maintenance of intelligence services to detect threats
• the protection of classified information

See also:

• National Security Adviser (U.S.)
• Nuclear deterrence

National Security is also a movie, made in 2003, starring Martin Lawrence. See National Security (movie) .