Threat Advisory Levels

A color-coded indicator of the likelihood of a forthcoming terrorist attack on the United States or its citizens and interests abroad. Introduced by the U.S. Department of Homeland Security in the wake of the terrorist attacks of September 11, 2001, the threat advisory levels function both to alert U.S. citizens to the possibility of attack and to direct federal and state agencies to take enhanced security precautions. The threat advisory level is set by the president of the United States on the advice of the secretary of homeland security.

There are five threat advisory levels: green (low risk of attack), blue (guarded risk of attack), yellow (elevated risk of attack), orange (high risk of attack), and red (severe risk of attack). Each threat level ostensibly adds an additional layer of security and subsumes all of the extra precautions taken at lower threat levels. The Homeland Security Advisory System specifies what precautions should be taken at each threat level.

During a blue condition, federal agencies check communications with designated emergency response and command locations and review emergency response procedures. When the threat advisory is yellow, law-enforcement agencies increase their surveillance of critical locations and coordinate emergency plans with other state and local personnel. During an orange alert, federal agencies take additional precautions at public events and restrict access to threatened facilities. With a red alert, the federal government increases personnel and resource levels to address critical emergency needs, mobilizes specially trained teams, and closes affected public and government facilities.

Critics of the threat advisory system maintain that its five incremental levels hold little practical utility, in that neither the green (low) level nor the blue (guarded) level will ever likely be set. Supporters of the threat advisory system, however, argue that it has been a highly effective tool for raising public awareness at critical moments and for helping governments make opportune policy and resource decisions.