Those of us who are GenXrs clearly remember the film “War Games.” We will not rehash that film, but it led to an entire generation being exposed to the DEFCON system.
Those of us who are GenXrs clearly remember the film “War Games” where a teenage hacker played by Matthew Broderick managed to hack into the Pentagon’s computer system and initiated a response that could have led to Global Thermonuclear War. We will not rehash that film, but it led to an entire generation being exposed to the DEFCON system.
From Wikipedia;
DEFCON 1 COCKED PISTOL Nuclear war is imminent or has already begun. Maximum readiness. Immediate response.
DEFCON 2 FAST PACE Next step to nuclear war. Armed forces ready to deploy and engage in less than six hours

DEFCON 3 ROUND HOUSE Increase in force readiness above that required for normal readiness. Air Force ready to mobilize in 15 minutes
DEFCON 4 DOUBLE TAKE Increased intelligence watch and strengthened security measures. Above normal readiness
DEFCON 5 FADE OUT Lowest state of readiness Normal readiness
Those who lived and served before, during the Cuban Missile Crisis, the 1973 Yom Kippur War, the 1976 North Korean Axe Incident, Operation Desert Storm, and 9/11 clearly have memories of the US going on High Alert, especially those who served at the Tip of the Spear. Those who lived and served afterwards only experienced it once thereafter, as Wikipedia notes below during the opening phase of Desert Storm, when the US Military was placed on DEFCON2.

According to some sites ESTIMATES the US is now on heightened alert, though we will not specify which level in order to avoid spreading any possible misinformation. NOTE. SUCH SITES ARE UNOFFICIAL SOURCES AND DOES NOT ACTUALLY REFLECT THE ACTUAL DEFCON STATE, AS SUCH INFORMATION REMAINS CLASSIFIED. Instead we prefer to speak of the history of the DEFCON system and which levels US forces have been in the past.
As events continue to play out overseas and all over the world, we believe a review of the DEFCON system changes is in order as there have been only 2 known instances of the US going on DEFCON2, during the Cuban Missile Crisis and during Desert Storm.
Per Wiki;

DEFCON 2
Cuban Missile Crisis
During the Cuban Missile Crisis on Oct. 16–28, 1962, the US Armed Forces (with the exception of United States Army Europe (USAREUR)) were ordered to DEFCON 3. On Oct. 24, Strategic Air Command (SAC) was ordered to DEFCON 2, while the rest of the US Armed Forces remained at DEFCON 3. SAC remained at DEFCON 2 until Nov. 15.
Persian Gulf War
On Jan.15, 1991, the Joint Chiefs of Staff declared DEFCON 2 in the opening phase of Operation Desert Storm during the Persian Gulf War
DEFCON 3
Yom Kippur War

On Oct. 6, 1973, Egypt and Syria launched a joint attack on Israel resulting in the Yom Kippur War. The United States became concerned that the Soviet Union might intervene, and on Oct. 25, US forces, including SAC, Continental Air Defense Command, European Command and the Sixth Fleet, were placed at DEFCON 3.
According to documents declassified in 2016, the move to DEFCON 3 was motivated by CIA reports indicating that the Soviet Union had sent a ship to Egypt carrying nuclear weapons along with two other amphibious vessels. Soviet troops never landed, although the ship supposedly transporting nuclear weapons did arrive in Egypt. Further details are unavailable and remain classified.
Over the following days, the various forces reverted to normal status with the Sixth Fleet standing down on Nov. 17.

Operation Paul Bunyan
Following the axe murder incident at Panmunjom on Aug. 18, 1976, readiness levels for US forces in South Korea were increased to DEFCON 3, where they remained throughout Operation Paul Bunyan.
September 11 attacks
During the September 11 attacks, Secretary of Defense Donald Rumsfeld ordered the DEFCON level be increased to 3, and also a stand-by for a possible increase to DEFCON 2. It was lowered to DEFCON 4 on Sep. 14.
Photo credit: U.S. Air Force
