Homeland Security Advisory System: Colors & History

Instructor: Ian Lord

Ian has an MBA and is a real estate investor, former health professions educator, and Air Force veteran.

In this lesson, we will review the workings and history of the Department of Homeland Security's former Homeland Security Advisory System. This was a way of communicating potential terrorist threats to government agencies and the public.

Homeland Security Advisory System

Joe is reminiscing with his friend about life before and immediately after the terrorist attacks of September 11th, 2001. He asked him about what color alert we are on right now, but his friend had no clue what he meant. After trying to look it up online and failing to find anything, Joe remembered that the system has since been replaced. Let's listen in on Joe's description of how the Homeland Security Advisory System worked.

Definition and Colors

The Homeland Security Advisory System (HSAS) was a tool for informing citizens, such as Joe, of the risk of a terrorist attack. The concept was based on the likelihood of terrorist attacks on individual citizens, as well as businesses and government agencies, so that they could adjust their security posture. The system is composed of five different threat alerts defined by the colors green, blue, yellow, orange, and red.

When the threat condition was in low condition or green alert, Joe could expect a low-risk of terrorist attacks. In a guarded condition, blue alert, there was an expectation that there could be possible terrorist activity of a general nature, but not a specific threat to any one particular target. By the time the threat reached an elevated condition, yellow alert, it meant that there was a significant expectation of terrorist attacks, but without an awareness of any specific targets.

In a high condition, orange alert, Joe would have been given the expectation for a high-risk of terrorism in a short time span. The highest alert level was for a severe condition, or red alert, that communicated to the public that an attack against a known target would soon or has already occurred.


The HSAS was introduced on March 12th, 2002 as part of the initiative to improve communication and coordination among government agencies and the American public for preparedness for acts of terrorism. Between 2002 and 2006, the alerts bounced back and forth between yellow and orange alerts, with a spike up to red in August 2006 for flights going from the United Kingdom to the US. Alerts stayed at yellow for most potential targets including mass transit and financial sectors, with the exception of commercial aviation which remained at orange alert.

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