With GPS systems becoming increasingly common, many countries are developing GPS jammers to prevent GPS-guided bombs from hitting their targets. Russia and China have been particularly aggressive in this field. Iraq has reportedly bought and used Russian GPS jammers which have distracted some US bombs from targets. The Air Force is planning to use an anti-jammer system developed by Lockheed Martin in the Joint Air-to-Surface Standoff Missile to defeat the current generation of low-powered jammers.--Stephen V Cole