text: SUBROC's tactical use was as an urgent-attack long-range weapon for time-urgent submarine targets that could not be attacked with any other weapon without betraying the position of the launching submarine by calling for an air-strike, or where the target was too distant to be attacked quickly with a torpedo launched from the submarine. The tactical rationale for SUBROC was similar to that for ASROC or Ikara. An added advantage was that SUBROC's approach to the target was not detectable by the target in time to take evasive action, although the warhead yield would appear to make evasive maneuvers unrealistic. However, SUBROC was less flexible in its use than Ikara or ASROC: since its only payload was a nuclear warhead, it could not be used to provide stand-off fire in a conventional (i.e., non-nuclear) engagement.
  SUBROC production ended in 1968. SUBROC was never used in combat, and all 285 W55 warheads were decommissioned in 1990 following the end of the Cold War. Because the nuclear warhead was an integral part of the weapon, SUBROC could not be exported to other navies, and there is no evidence that any were supplied to other NATO allies under the well-established arrangements for supplying other dual-key nuclear weapons. In 1980 a planned successor, the UUM-125 Sea Lance, was authorized. In 1982 the contract was awarded to Boeing. The system and its W89 warhead were cancelled in 1990 at the end of the Cold War.