Since the earliest introduction of radar into the air defense equation, there have been continuing efforts at electronic countermeasures. With slight variations, these countermeasures fall into one of three categories: one aircraft creating clutter on many radar screens to degrade detection and tracking, which is stand-off jamming (SOJ); a threatened aircraft deceiving an individual radar with special techniques, which is defensive electronic countermeasures (DECM); and modifying the signature characteristics of your own platform, which is called "stealth" or "low observable." The United States has been active in pursuing all three categories.
The ALQ-99 Tactical Jamming System in the Navy/Marine Corps EA-6Bs is the preeminent SOJ system in the world today. The United States initially developed a number of DECM systems for different aircraft. More recent systems, such as the Airborne Self Protect Jammer and the Integrated DECM with a towed decoy, were developed for use in numerous platforms. Of course, the United States is the world leader in stealth with the F- 117, B-2, and F-22.