DEFCON 3
DEFCON 3

September 11 Attacks

Maintained for several weeks following the attacks

Following the terrorist attacks on the World Trade Center and Pentagon, U.S. forces were raised to DEFCON 3.

Detailed Account

On September 11, 2001, the United States experienced the deadliest terrorist attack in its history. Following the attacks on the World Trade Center in New York City and the Pentagon in Washington D.C., the U.S. military was immediately placed on high alert. This marked the first time DEFCON 3 had been declared since the 1973 Yom Kippur War.

The alert status affected all branches of the military and led to unprecedented security measures across the country. Fighter jets were scrambled to patrol American airspace, and all civilian aircraft were grounded nationwide.

Commands Affected

All Commands

About DEFCON 3

DEFCON 3 - ROUND HOUSE

Increase in force readiness above normal. Air Force ready to mobilize in 15 minutes.

Above normal readiness. Increased intelligence watch. Some forces on higher alert.

Learn More About DEFCON 3

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