Electronic warfare

Electronic warfare is defined by NATO and the U.S. Department of Defense as military action involving the use of electromagnetic energy to control the electromagnetic spectrum and attack an adversary. It is divided into three primary domains: electronic attack (EA), electronic protection (EP), and electronic support (ES). EA involves offensive use of EM energy to degrade or destroy enemy capabilities, such as jamming radar or communications. EP encompasses actions taken to protect friendly forces from the effects of EA, including hardening and frequency agility. ES involves passive detection and interception of electromagnetic emissions for threat recognition and targeting.

The origins of electronic warfare trace back to the Russo-Japanese War (1904–1905), when Russian naval operators used radio intercept to detect Japanese fleet movements. During World War II, EW matured rapidly with the development of radar and countermeasures, such as the British 'Window' (chaff) that confused German radar. The Cold War saw the rise of dedicated EW aircraft and satellites, and the Vietnam War introduced the use of anti-radiation missiles like the AGM-45 Shrike. In recent conflicts, EW has become integral to network-centric warfare, with cyber-electromagnetic activities merging cyber and EW operations.

Electronic attack includes both lethal and non-lethal means to disrupt, deny, or destroy enemy use of the spectrum. Non-lethal methods include jamming, spoofing, and chaff/flares, while lethal methods include anti-radiation missiles and directed-energy weapons. A notable example is the U.S. Navy's EA-18G Growler, which can jam enemy radar and communications while also firing AGM-88 HARM missiles. In the 2007 Israeli strike on Syria's alleged nuclear reactor, Israeli aircraft used electronic attack to blind Syrian air defenses, demonstrating the effectiveness of integrated EW.

Electronic protection involves measures to ensure friendly use of the spectrum despite enemy EW. This includes spread-spectrum techniques, frequency hopping, and emission control (EMCON). Modern systems like the Link 16 tactical data link employ frequency hopping and encryption to resist jamming. Additionally, hardening of electronics against electromagnetic pulse (EMP) is a form of EP, critical for nuclear survivability.

Electronic support (ES) is the passive collection and analysis of electromagnetic emissions for threat recognition, targeting, and situational awareness. It includes signals intelligence (SIGINT), electronic intelligence (ELINT), and communications intelligence (COMINT). ES platforms range from ground-based listening posts to dedicated aircraft like the RC-135 Rivet Joint. ES data is crucial for electronic order of battle (EOB) and for cueing electronic attack.

Beyond the conventional domains, electronic warfare has several niche and often overlooked facets. One is the use of EW in space, where satellites are vulnerable to jamming and spoofing; the U.S. Space Force has designated EW as a core capability. Another is the role of EW in countering improvised explosive devices (IEDs) in Iraq and Afghanistan, where jammers were deployed on vehicles to disrupt remote detonation signals. Additionally, the concept of 'cognitive EW' uses machine learning to adapt jamming strategies in real time, a field pioneered by DARPA's Behavioral Learning for Adaptive Electronic Warfare (BLADE) program. A historical curiosity is the 'Battle of the Beams' in WWII, where German navigation beams were bent by British countermeasures, leading to the development of the Oboe and Gee systems.

Contemporary electronic warfare faces challenges from spectrum congestion, the proliferation of low-cost drones, and the integration of 5G technologies. The U.S. Army's 'Electronic Warfare Planning and Management Tool' (EWPMT) is being developed to manage EW in dense electromagnetic environments. Future trends include the use of artificial intelligence for spectrum sensing and autonomous jamming, as well as the development of high-power microwave (HPM) weapons for drone swarms. The convergence of cyber and EW, termed 'cyber-electromagnetic activities' (CEMA), is a key doctrinal evolution in the U.S. military.

Electronic attack (EA)

The use of electromagnetic energy to degrade, neutralize, or destroy enemy combat capability.

Electronic protection (EP)

Actions taken to protect friendly use of the electromagnetic spectrum from enemy EW.

Electronic support (ES)

Passive detection and identification of electromagnetic emissions for threat recognition and targeting.

Chaff

Radar countermeasure consisting of small metallic strips that create false echoes.

Anti-radiation missile

A missile designed to home in on and destroy enemy radar emitters.

EMCON

Emission control; the management of electromagnetic emissions to reduce detectability.