First strike (nuclear strategy)

In nuclear strategy, a first strike or preemptive strike is a preemptive surprise attack employing overwhelming force. First strike capability is an attacking country's ability to significantly cripple another nuclear power's second strike retaliatory capacity. The preferred methodology is to attack the opponent's strategic nuclear weapon facilities (missile silos, submarine bases, bomber airfields), command and control sites (a decapitation strike), and storage depots first. The strategy is called counterforce.

During the 1950s, first strike strategy required strategic bomber sorties taking place over hours and days. In the 1960s, the deployment of intercontinental ballistic missiles cut the first strike duration to 30 minutes. Also during the Cold War, medium- and intermediate-range ballistic missiles, such as those involved in the Cuban Missile Crisis and Euromissile Crisis, as well as submarine-launched ballistic missiles, reduced the time even further, often below 10 minutes.

Second strike countermeasures to effectively deter first strikes include early warning systems, launch on warning for missile silos, continuous nuclear-capable submarine stealth patrols, and continuous airborne patrols.