Like all clich s, the phrase national security has lost some of its meaning through over-use.
National security means preventing war or terrorism on American soil.
The Founding Fathers saw national security as the very first duty of government. The Constitution makes it clear how important national security was to them. Likewise, the first duty listed for the President is to be commander in chief of the army and navy. National security is a very serious matter. When we fail to maintain it, people die.