The R-12 Dvina was a theatre ballistic missile developed and deployed by the Soviet Union during the Cold War. Its GRAU designation was 8K63, and it was given the NATO reporting name of SS-4 Sandal. The R-12 rocket provided the Soviet Union with the capability to attack targets at medium ranges with a megaton-class thermonuclear warhead and constituted the bulk of the Soviet offensive missile threat to Western Europe. Deployments of the R-12 missile in Cuba caused the Cuban Missile Crisis in 1962. A total of 2335 missiles were produced; all were destroyed in 1993 under the START II treaty.

The Cuban Missile Crisis, also known as the October Crisis in Cuba, or the Caribbean Crisis, was a 13-day confrontation between the governments of the United States and the Soviet Union, when American deployments of nuclear missiles in Italy and Turkey were matched by Soviet deployments of nuclear missiles in Cuba. The crisis lasted from 16 to 28 October 1962. The confrontation is widely considered the closest the Cold War came to escalating into full-scale nuclear war.