Homeland Security Advisory System

In the United States, the Homeland Security Advisory System was a color-coded terrorism threat advisory scale. 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. It was often called the "terror alert level" by the U.S. media. The system was replaced on April 27, 2011 with a new system called the National Terrorism Advisory System.

The system was created by Homeland Security Presidential Directive 3 on March 11, 2002, in response to the September 11 attacks. It was meant to provide a "comprehensive and effective means to disseminate information regarding the risk of terrorist acts to federal, state, and local authorities and to the American people." It was unveiled March 12, 2002, by Tom Ridge, then the Assistant to the President for Homeland Security. However, responsibility for developing, implementing and managing the system was given to the U.S. Attorney General.

In January 2003, the new Department of Homeland Security (DHS) began administering the system. 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.

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. Napolitano, who made the announcement at George Washington University, said the color-coded system often presented "little practical information" to the public and that the new system will provide alerts "specific to the threat" and that "they will have a specified end date."

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