The R-12 was a theatre ballistic missile developed and deployed by the Soviet Union during the Cold War. Its GRAU designation was 8K63 (8K63U or 8K63У in Cyrillic for silo-launched version), and it was given the NATO reporting name of SS-4 Sandal. The R-12 rocket provided 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.