Because radar systems find and make measurements of noncooperative targets, it motivates various countering actions. Motorists might want to deprive the highway patrolman of information about their speed to avoid a ticket. Certainly, nations want to deny other nations all kinds of information, particularly in times of tension or war. Electronic warfare (EW) seeks to deny, degrade, and/or deceive an adversary's radar systems to ensure successful completion of the friendly force's mission [see the numerous references at the end of this chapter]. EW is divided into three components: electronic support (ES), electronic attack (EA), and electronic protection (EP). The purpose of ES is to intercept, identify, and locate radar systems. The purpose of EA is to “attack”radar systems to negatively affect their performance and/or capability. The purpose of EP is to protect radar systems from ES or EA. Traditionally, ES has been known as electronic support measures (ESM), EA has been known as electronic countermeasures (ECM), and EP has been known as electronic countercountermeasures (ECCM). An international professional EW society called the Association of Old Crows (AOC) advances strategy, policy, and programs for EW and electromagnetic spectrum operations. Since the fate of nations may depend on the effectiveness of ES, EA, and EP, details related to specific EW concepts and systems are highly classified. However, many useful general principles of ES, EA, and EP can be discussed and quantified.