In the 1980s, NATO countries had an agreement that the USA would develop a medium-range air-to-air missile (the AIM-120 AMRAAM) to replace the AIM_7 Sparrow, and Britain and Germany would develop a short_range air_to_air missile (the ASRAAM) to replace the AIM-9 Sidewinder.
After numerous development delays with ASRAAM, the USA later changed its mind and developed an improved Sidewinder, the AIM-9X. Note that the AIM-9X uses the same seeker head as the ASRAAM..
Germany left the ASRAAM project in the early 1990s, and in the spring of 1995 initiated an improved version of the Sidewinder, the IRIS-T. This decision was motivated by new insights into the performance of the Russian AA-11 Archer missile carried by the MiG-29s which Germany inherited during reunification.
Notes
The guidance system can lock on to a target 90 degrees off boresight
The AIM-132 ASRAAM is a high speed, highly manoeuvrable, heat-seeking, air-to-airmissile.
Although ASRAAM is predominantly intended for use in the within-visual-range (WVR) arena, it also has capabilities that permit its use in the beyond-visual-range arena.
In a typical WVR engagement, the ASRAAM is slaved to the target either visually or by the launch aircraft's onboard sensors.