The specific government actions triggered by different threat levels were not always been revealed to the public, although the government had provided general guidance for civilians and federal agencies. Inspired by the success of the forest fire color system, the scale consists of five color-coded threat levels, which were intended to reflect the probability of a terrorist attack and its potential gravity. Napolitano, who made the announcement at George Washington University, said the color-coded system often presented РІР‚Сљlittle practical informationРІР‚Сњ to the public and that the new system will provide alerts РІР‚Сљspecific to the threatРІР‚Сњ and that РІР‚Сљthey will have a specified end date.РІР‚Сњ On January 27, 2011, Secretary of Homeland Security Janet Napolitano announced that the Homeland Security Advisory System would be replaced by a new two-level National Terrorism Advisory System in April 2011. The decision to publicly announce threat conditions is made by the Secretary of Homeland Security in consultation with the Assistant to the President for Homeland Security, according to Homeland Security Presidential Directive-5. In January 2003, the new Department of Homeland Security (DHS) began administering the system. However, responsibility for developing, implementing and managing the system was given to the U.S. It was meant to provide a РІР‚Сљcomprehensive and effective means to disseminate information regarding the risk of terrorist acts to federal, state, and local authorities and to the American people.РІР‚Сњ It was unveiled March 12, 2002, by Tom Ridge, then the Assistant to the President for Homeland Security. The system was created by Homeland Security Presidential Directive 3 on March 11, 2002, in response to the September 11 attacks. The system was replaced on April 27, 2011, with a new system called the National Terrorism Advisory System. It was often called the РІР‚Сљterror alert levelРІР‚Сњ by the U.S. The different levels triggered specific actions by federal agencies and state and local governments, and they affected the level of security at some airports and other public facilities. In the United States, the Homeland Security Advisory System was a color-coded terrorism threat advisory scale.

Current defcon level homeland security