The proliferation of surface-to-air missiles (SAMs) has made the Suppression of Enemy Air Defence a priority for any modern air force intending offensive action. Knocking out air search radars and fire control radars is an essential part of this mission. ARMs must have sufficient range that the launch platform is out of range of the SAMs, high speed to reduce the risk of being shot down and a seeker that can detect a range of radar types, but they do not need a particularly big warhead.
The Soviet Union's first ARM was developed by the Raduga OKB engineering group responsible for the Soviet Union's missiles for heavy bombers. The Kh-22P was developed from the 6-tonne Raduga Kh-22 (AS-4 'Kitchen') missile. Experience gained with this led in 1973 to the Kh-28 (AS-9 'Kyle') carried by tactical aircraft such as the Su-7B, Su-17 and Su-24. It had Mach 3 capability and a 120 km (60 nmi) range, greater than the contemporary AGM-78 Standard ARM. The Kh-28 was succeeded by the Kh-58 in 1978, which has similar speed and range but replaces the dual-fuel rocket motor with a much safer RDTT solid propellant.
The development of more sophisticated SAMs such as the MIM-104 Patriot and the US Navy's Aegis combat system put pressure on the Soviets to develop better ARMs in turn. Zvezda came at the problem from a different angle to Raduga, having a background in lightweight air-to-air missiles. However in the mid-1970s they had developed the successful Kh-25 family of short-range air-to-surface missiles, including the Kh-25MP (AS-12 'Kegler') for anti-radar use. Zvezda started work on a long-range ARM and the first launch of the Kh-31 was in 1982. It entered service in 1988 and was first displayed in public in 1991, the Kh-31P at Dubai and the Kh-31A at Minsk.
In December 1997 it was reported that a small number of Kh-31's had been delivered to China, but that "production had yet to begin". It was around this time that the Russians sold Su-30MKK 'Flanker-G' aircraft to the Chinese. It seems that the original deliveries were of the original Russian model designated as X-31, to allow testing whilst the KR-1 model was being developed for licence production. Local production may have started by July 2005.
Russian development has accelerated since Zvezda was subsumed into the Tactical Missiles Corporation in 2002, with the announcement of the 'D' extended range models and the 'M' model mid-life updates (see Variants section below).