Updated October 29 2020 Defense Primer Electronic Warfare Electronic warfare EW as defined by the Department of Defense DOD are military activities that use electromagnetic energy to control the electromagnetic spectrum “the spectrum” and attack an enemy The spectrum is a range of frequencies for electromagnetic energy EW supports command and control C2 by allowing military commanders’ access to the spectrum to communicate with forces while preventing potential adversaries from accessing the spectrum to develop an operational picture and communicate with their forces Some have argued that EW is a component of antiaccess area denial A2 AD campaigns Role of EW in Military Operations Since the introduction of two-way radios militaries have become dependent on the spectrum This reliance has expanded over the past century to include nearly every weapon system Applications include  radio frequencies to communicate with friendly forces  microwaves for tactical data-links radars and satellite communications  infrared for intelligence and to target enemies and  lasers across the entire spectrum to communicate transmit data and potentially destroy a target Modern militaries rely on communications equipment that uses broad portions of the spectrum to conduct military operations This allows forces to talk transmit data provide navigation and timing information and to command and control forces all over the world They also rely on this to know where adversaries are what adversaries are doing where friendly forces are and what effects weapons achieve As a result modern militaries attempt to dominate the spectrum through electronic warfare From the perspective of military operations there are three broad divisions of electronic warfare  Electronic protection involves actions to protect access to the spectrum for friendly military assets  Electronic attack uses electromagnetic energy to degrade or deny an enemy’s use of the spectrum  EW support identifies and catalogues emissions of friendly or enemy forces to either protect U S forces or develop a plan to deny an enemy’s access to the spectrum These subsets of EW often mutually support each other in operations EW support uses equipment to assess both friendly and adversary electronic emissions This information can then be used to develop a protection plan to maintain access to the spectrum or an attack plan to deny adversaries vital access Radar jamming electronic attack can serve a protection function for friendly forces to penetrate defended airspace and it prevents an adversary from having a complete operating picture In general the more advanced a military adversary the greater role EW plays in combat Types of EW Capabilities As electronic warfare affects all military domains—land air sea space and cyberspace—each of the military services has its own EW capabilities and programs EW capabilities are traditionally categorized into two distinct categories terrestrial and airborne Because each kind of EW has its respective advantages and disadvantages multiple capabilities may be required to provide a desired effect For example airborne EW is used to intercept decrypt and disrupt communications radars and other C2 systems over a large area However these capabilities may be limited by aircraft endurance and are therefore unable to provide certain EW effects Examples of airborne EW programs include the E-2 Hawkeye the EA-18G Growler the RC-135 Rivet Joint and the EC-130H Compass Call Figure 1 How EW Affects the Spectrum Source https cyberdefense com spectrum-warfare https crsreports congress gov Defense Primer Electronic Warfare Terrestrial EW sensors and jammers—which can be located on land or on ships at sea—are limited by the amount of power available these capabilities are also limited due to variance in the terrain in which they operate Ground EW capabilities were traditionally used to intercept and to jam radios and artillery radars More recent uses include jamming improvised explosive devices IEDs in Iraq and Afghanistan Representative ground EW capabilities include the vehicle-mounted Counter Remote Controlled IEDs CREW Duke system and the Thor III dismounted CREW system Modern-day military operations also rely on satellite-based EW capabilities including for broad area surveillance and early-warning communications command and control Specific programs include  Space Based Infrared System SBIRS constellation  electronic intelligence by satellite ELISA electronic intelligence satellites and  space-based radar systems DOD EW Policy The National Defense Strategy released in 2018 emphasized the return of great-power competition reflecting China’s and Russia’s ongoing efforts to modernize their forces to counter U S military advantages In addition the congressionally mandated National Defense Strategy Commission which independently evaluated DOD strategy stated that the United States is losing its advantages in electronic warfare hindering the nation’s ability to conduct military operations against capable adversaries The commission recommended increasing EW investments and developing new concepts to regain U S military advantage Each service has incorporated EW capabilities into platforms and combat systems and is currently working to modernize its existing capabilities Army The Secretary of the Army and the Chief of Staff of the Army testified this year that developing new EW capabilities and programs was the Army’s fourth most important modernization The Army plans to invest in both airborne and ground-based EW programs aimed at making the service more competitive with peer adversaries This investment includes standing up a new organization devoted to the EW mission procuring long-endurance unmanned airborne EW systems and unit-level training Marine Corps The Commandant of the Marine Corps has testified in posture statements since 2017 about the need for modern EW capabilities for expeditionary maritime operations The Marine Corps continues to sustain and modernize its radio battalions—units specifically designed around signatures intelligence and electronic warfare—alongside additional aviation programs Such programs include the F-35B Lightning II aircraft Another initiative outlined in the most recent Marine Corps’ concept is signature management which aims to limit emissions so that adversaries have less precise information about U S operating locations Navy The Navy has several new operational concepts it intends to use to counter adversaries including the Naval Integrated Fire Control-Counter Air NIFC-CA concept designed to help the carrier air wing to better counter adversaries in denied or degraded environments The Chief of Naval Operations in his 2018 posture testimony before the Armed Services Committees discussed needing to invest more in EW capabilities for the surface fleet The EA-18G Growler aircraft which is the backbone of the Navy’s EW programs continues to receive funding to modernize its capabilities including funding for the Next Generation Jammer Air Force The Air Force’s concepts of air superiority and multidomain command and control require assured access to the spectrum The Secretary of the Air Force and the Air Force Chief of Staff stated during their 2018 posture hearing the need to maintain EW capabilities to support the Air Force’s future development As a result the service is upgrading EC-130H Compass Call EW payloads in the near-term The Air Force requested funding for two EC37s with an intent to purchase 10 over the next 10 years Organization of EW DOD has several organizations responsible for developing and maintaining EW capabilities The EW Executive Committee—led by the Deputy Secretary of Defense—is tasked with synchronizing and integrating EW across DOD components by sharing tactics techniques procedures intelligence and technologies The EW EXCOM is responsible for establishing DOD EW policy The FY2019 National Defense Authorization Act NDAA mandated the creation of an Electromagnetic Spectrum Operations Cross Functional Team to develop an electronic warfare strategy including assessments of vulnerabilities and capability gaps leading to an acquisition plan The Cross Functional Team released the Electromagnetic Spectrum Superiority Strategy on October 29 2020 CRS Products CRS Report R44572 U S Airborne Electronic Attack Programs Background and Issues for Congress by John R Hoehn CRS Report R45919 Ground Electronic Warfare Background and Issues for Congress by John R Hoehn CRS In Focus IF11155 Defense Primer Military Use of the Electromagnetic Spectrum by John R Hoehn Other Resources DOD Electromagnetic Spectrum Superiority Strategy October 29 2020 DOD Joint Pub 3-85 Joint Electronic Magnetic Spectrum Operations May 22 2020 DOD DOD Directive 3222 4 Electronic Warfare Policy March 26 2014 with Change 2 Effective August 31 2018 John R Hoehn Analyst in Military Capabilities and Programs https crsreports congress gov Defense Primer Electronic Warfare IF11118 Disclaimer This document was prepared by the Congressional Research Service CRS CRS serves as nonpartisan shared staff to congressional committees and Members of Congress It operates solely at the behest of and under the direction of Congress Information in a CRS Report should not be relied upon for purposes other than public understanding of information that has been provided by CRS to Members of Congress in connection with CRS’s institutional role CRS Reports as a work of the United States Government are not subject to copyright protection in the United States Any CRS Report may be reproduced and distributed in its entirety without permission from CRS However as a CRS Report may include copyrighted images or material from a third party you may need to obtain the permission of the copyright holder if you wish to copy or otherwise use copyrighted material https crsreports congress gov IF11118 · VERSION 9 · UPDATED