preventative will work ish....but u have to understand the placement of the CMS if you put it out and its not in the path of the radar or IR it usually wont draw the radar off..if u dispense and move away from the CMS then they have no use....also when evading and or fighting remember that chaff flares will only work if u put them out when the missile is tracking close to you ....otherwise whats the point ????? also as with everything understand how the missiles are trying to kill u and maneuver according to your airspeed and altitude to defeat.