National security referred to the national security force. You could refer to the following novel recommendations about national security: The Mysterious Mission of the National Security Agency 2. The Anti-corruption Storm of the National Security Bureau National Security Agency: Strategic Defense National Security Agency: Asian Shield 5 " The Secret Operation of the National Security Bureau " These novels were all about national security forces, involving anti-corruption, anti-terrorism, intelligence, security, and other aspects. The plot was compact and the writing was beautiful. It was worth reading.