The National Terrorism Advisory System, or NTAS, replaces the color-coded Homeland Security Advisory System (HSAS). This system will more effectively communicate information about terrorist threats by providing timely, detailed information to the public, government agencies, first responders, airports and other transportation hubs, and the private sector.
It recognizes that Americans all share responsibility for the nation’s security, and should always be aware of the heightened risk of terrorist attack in the United States and what they should do.
Irregular Warfare 