Launch on warning

Launch on warning (LOW) is a strategy of using nuclear weapons that gained recognition during the Cold War between the United States and the Soviet Union. Launch on warning became an important part of mutually assured destruction (MAD) theory as a result of the invention of intercontinental ballistic missiles (ICBMs). Under the LOW strategy, nuclear weapons are launched as retaliation upon receiving warning signs of an enemy nuclear attack, even while the incoming missiles are still in the air and before detonation occurs. U.S. land-based missiles can reportedly be launched
within five minutes of a presidential decision to do so, and submarine-based missiles can be launched within 15 minutes.http://www.ucsusa.org/sites/default/files/attach/2015/01/Hair-Trigger%20FAQ.pdf

 References 

Category:Nuclear weapons