Abstract: Recent conflicts have demonstrated that the threat from Infrared (IR) Seeker Surface to Air Missiles (SAMs) is significant. Air operations in Bosnia and Kosovo were severely hampered by the requirement to fly above the maximum engagement range of SAM systems. In particular, the threat posed by highly mobile, easily concealed Shoulder Launched SAMs limited the use of low-level reconnaissance, attack helicopters and offensive air support. The development of the passive Missile Warning Sensor (MWS) has been seen as a way of redressing the aircraft-missile engagement balance by offering to re-establish the validity of safe flying operations at low level. Unfortunately, testing of Defensive Aids Suites (DAS) employing MWS technology indicates that there are many problems associated with the integration and operation of a missile detection, warning and engagement system. The paper outlines the technology and deployment doctrine associated with the MWS and provides options that the IR Seeker SAM designer and/or operator could utilise to overcome MWS-based DAS.