R-400 Oka

OTR-23 Oka SS-23 Spider
A 9P71 TEL at the National Museum of Military History in Sofia, Bulgaria.
Type	Tactical ballistic missile
Place of origin	Soviet Union
Service history
Used by	See Operators
Production history
Designer	KB Mashinostroyeniya (Kolomna)
Manufacturer	Votkinsk Machine Building Plant
Produced	1979 – 1987
Specifications
Weight	4,360 kg (9,610 lb)
Length	7.53 m (24.7 ft)
Diameter	0.89 m (2 ft 11 in)
Warhead	Nuclear 50-100 kt, HE fragmentation, submunition, or chemical
Engine	Single-stage Solid-fuel rocket
Operational range	500 km (310 mi)
Guidance system	Inertial with terminal topographic DSMAC active radar
Accuracy	30-150 m CEP
Launch platform	Mobile TEL

The OTR-23 Oka (Russian: OTP-23 «Ока»; named after Oka River) was a mobile theatre ballistic missile (Russian: оперативно-тактический ракетный комплекс) deployed by the Soviet Union near the end of the Cold War to replace the obsolete SS-1C 'Scud B'. It carried the GRAU index 9K714 and was assigned the NATO reporting name SS-23 Spider. The introduction of the Oka significantly strengthened Soviet theatre nuclear capabilities as its range and accuracy allowed it not only to strike hardened NATO targets such as airfields, nuclear delivery systems, and command centers, but moving targets as well. It also had a fast reaction time, being able to fire in approximately five minutes, and was nearly impossible to intercept, thereby allowing it to penetrate defenses.

The main components of the 9K714 system were:

The operational life of the Oka was limited and controversial. The Soviet military asserted that the Oka only had a maximum range of 250 miles (400 km). American experts on the contrary estimated it had a greater range. In 1987, Mikhail Gorbachev proposed to George Schultz that he would unilaterally remove all Okas, if it would prevent the United States from building up its own short-range nuclear forces in Europe, despite the fact that the Soviet military was in favor of the Oka. Schultz however lacked the authority to act on the suggestion. Gorbachev included the Oka in the class of systems to be discontinued as part of the INF Treaty as a gesture of goodwill, even though Soviet assertions of its maximum range did not put it outside of the specifications of the treaty.

There was diplomatic controversy over this weapons system in April 1990 when the Soviets informed the US of their covert transfer of at least 120 missiles to the Warsaw Pact states of Czechoslovakia, Bulgaria, and East Germany during the time of negotiation of the Intermediate-Range Nuclear Forces Treaty. Evidence indicates that the missiles were transferred with conventional warheads only, although equipment to load Soviet nuclear warheads was apparently retained.