National security
National security was the secure status of a state. In the United States of America, national security fell under the auspices of the National Security Agency.
In 1947, after being threatened by Captain Wainwright during an interrogation, Nog the "Martian" asked whether America had laws against torture. Wainwright then replied, "Not when it comes to National Security." (DS9: "Little Green Men")
In 2370, Gul Evek refused to reveal his sources of information relating to a supposed Maquis plot, saying it would risk Cardassian national security. Chief Archon Makbar accepted his answer. (DS9: "Tribunal")