<P> On January 15, 1991, the Joint Chiefs of Staff declared DEFCON 2 in the opening phase of Operation Desert Storm during the Persian Gulf War . </P> <P> On October 6, 1973, Egypt and Syria launched a joint attack on Israel resulting in the Yom Kippur War . The U.S. became concerned that the Soviet Union might intervene, and on October 25, U.S. forces, including Strategic Air Command, Continental Air Defense Command, European Command and the Sixth Fleet, were placed at DEFCON 3 . </P> <P> According to documents declassified in 2016, the move to DEFCON 3 was motivated by Central Intelligence Agency 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, though the ship supposedly transporting nuclear weapons did arrive in Egypt . Further details are unavailable and may remain classified . </P> <P> Over the following days, the various forces reverted to normal status with the Sixth Fleet standing down on November 17 . </P>

What defcon level is the us at right now