noun
DEFCON; Defense Readiness Condition
A U.S. military alert state system; used in Japanese media and conversation to refer to levels of military readiness or, metaphorically, any heightened state of alert.
アメリカ軍はデフコン3を発令した。
The U.S. military declared DEFCON 3.
彼は試験前でデフコンレベルが上がっている。
His DEFCON level is rising before the exam.