Updated September 29, 2021
Defense Primer: Electronic Warfare
Electronic warfare (EW), as defined by the Department of
Electronic protection involves actions to protect access
Defense (DOD), are military activities that use
to the spectrum for friendly military assets.
electromagnetic energy to control the electromagnetic
Electronic attack uses electromagnetic energy to
spectrum (“the spectrum”) and attack an enemy. The
degrade or deny an enemy’s use of the spectrum.
spectrum is a range of frequencies for electromagnetic
EW support identifies and catalogues emissions of
energy. EW supports command and control (C2) by
friendly or enemy forces to either protect U.S. forces or
allowing military commanders’ access to the spectrum to
develop a plan to deny an enemy’s access to the
communicate with forces, while preventing potential
spectrum.
adversaries from accessing the spectrum to develop an
These subsets of EW often mutually support each other in
operational picture and communicate with their forces .
operations. EW support uses equipment to assess both
Some have argued that EW is a component of anti-
friendly and adversary electronic emissions. This
access/area denial (A2/AD) campaigns.
information can then be used to develop a protection plan to
Role of EW in Military Operations
maintain access to the spectrum or an attack plan to deny
adversaries vital access. Radar jamming (electronic attack)
Since the introduction of two-way radios, militaries have
can serve a protection function for friendly forces to
become dependent on the spectrum. This reliance has
penetrate defended airspace, and it prevents an adversary
expanded over the past century to include nearly every
from having a complete operating picture.
weapon system. Applications include
radio frequencies to communicate with friendly forces;
In general, the more advanced a military adversary, the
microwaves for tactical data-links, radars, and satellite
greater role EW plays in combat.
communications;
infrared for intelligence and to target enemies; and
Types of EW Capabilities
lasers across the entire spectrum to communicate,
As electronic warfare affects all military domains —land,
transmit data, and potentially destroy a target.
air, sea, space, and cyberspace—each of the military
services has its own EW capabilities and programs. EW
Modern militaries rely on communications equipment that
capabilities are traditionally categorized into two distinct
uses broad portions of the spectrum to conduct military
categories: terrestrial and airborne. Because each kind of
operations. This allows forces to talk, transmit data, provide
EW has its respective advantages and disadvantages,
navigation and timing information, and to command and
multiple capabilities may be required to provide a desired
control forces all over the world. They also rely on this to
effect. For example, airborne EW is used to intercept,
know where adversaries are, what adversaries are doing,
decrypt, and disrupt communications, radars, and other C2
where friendly forces are, and what effects weapons
systems over a large area. However, these capabilities may
achieve. As a result, modern militaries attempt to dominate
be limited by aircraft endurance and are therefore unable to
the spectrum through electronic warfare. From the
provide certain EW effects. Examples of airborne EW
perspective of military operations, there are three broad
programs include the E-2 Hawkeye, the EA-18G Growler,
divisions of electronic warfare
the RC-135 Rivet Joint, and the EC-130H Compass Call.
Figure 1. How EW Affects the Spectrum
Source: https://cyberdefense.com/spectrum-warfare.
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Defense Primer: Electronic Warfare
Terrestrial EW sensors and jammers —which can be located
Fire Control-Counter Air (NIFC-CA) concept, designed to
on land or on ships at sea—are limited by the amount of
help the carrier air wing to better counter adversaries in
power available; these capabilities are also limited due to
denied or degraded environments. The Chief of Naval
variance in the terrain in which they operate. Ground EW
Operations, in his 2018 posture testimony before the Armed
capabilities traditionally focused on intercepting and
Services Committees discussed investing more in EW
jamming radios and artillery radars. Recent uses include
capabilities for the surface fleet. The EA-18G Growler
jamming improvised explosive devices (IEDs ).
aircraft, which is the backbone of the Navy’s EW programs,
Representative ground EW capabilities include the vehicle-
continues to receive funding to modernize its capabilities,
mounted Counter Remote Controlled IEDs (CREW) Duke
including funding for the Next Generation Jammer.
system and the Thor III dismounted CREW system.
Air Force
Modern-day military operations also rely on satellite-based
The Air Force’s concepts of air superiority and
EW capabilities, including for broad area surveillance and
multidomain command and control require assured access
early-warning, communications, command and control.
to the spectrum. The Secretary of the Air Force and the Air
Specific programs include
Force Chief of Staff stated during their 2018 posture
hearing the need to maintain EW capabilities to support the
Space Based Infrared System (SBIRS) constellation;
Air Force’s future development. Thus, the service is
electronic intelligence by satellite (ELISA) electronic
upgrading EC-130H Compass Call EW payloads and
intelligence satellites; and
procuring EC-37s, with an intent of purchasing new 10
space-based radar systems.
aircraft. Six aircraft are already on contract.
DOD EW Policy
Organization of EW
The National Defense Strategy, released in 2018,
DOD has several organizations responsible for developing
emphasized the return of great-power competition,
and maintaining EW capabilities. The EW Executive
reflecting China’s and Russia’s ongoing efforts to
Committee—led by the Deputy Secretary of Defense—is
modernize their forces to counter U.S. military advantages.
tasked with synchronizing and integrating EW across DOD
In addition, the congressionally mandated National Defense
components by sharing tactics, techniques, procedures, and
Strategy Commission, which independently evaluated DOD
technologies. The EW EXCOM also establishes DOD EW
strategy, stated that the United States is losing its
policy. The FY2019 National Defense Authorization Act
advantages in electronic warfare, hindering the nation’s
directed the creation of an Electromagnetic Spectrum
ability to conduct military operations against capable
Operations Cross Functional Team to develop an electronic
adversaries. The commission recommended increasing EW
warfare strategy, including assessments of vulnerabilities
investments and developing new concepts to regain U.S.
and capability gaps, leading to an acquisition plan. The
military advantage. Each service has incorporated EW
Electromagnetic Spectrum Superiority Strategy was
capabilities into platforms and combat systems and is
published on October 29, 2020.
currently working to modernize its existing capabilities.
Army
CRS Products
The Secretary of the Army and the Chief of Staff of the
CRS Report R44572, U.S. Airborne Electronic Attack Programs:
Army testified this year that developing new EW
Background and Issues for Congress, by John R. Hoehn
capabilities and programs was the Army’s fourth most
CRS Report R45919, Ground Electronic Warfare: Background
important modernization. The Army plans to invest in both
and Issues for Congress, by John R. Hoehn
airborne and ground-based EW programs aimed at making
CRS In Focus IF11155, Defense Primer: Military Use of the
the service more competitive with peer adversaries. This
Electromagnetic Spectrum, by John R. Hoehn
investment includes standing up a new organization
devoted to the EW mission, procuring long-endurance,
CRS In Focus IF11882, Defense Primer: Directed-Energy
unmanned airborne EW systems, and unit-level training.
Weapons, by Kel ey M. Sayler and John R. Hoehn
Marine Corps
Other Resources
The Commandant of the Marine Corps has testified since
DOD. Electromagnetic Spectrum Superiority Strategy,
2017 about requiring modern EW capabilities for
October 29, 2020
expeditionary maritime operations. The Marine Corps
continues to sustain and modernize its radio battalions—
Joint Pub. 3-85, Joint Electronic Magnetic Spectrum
units specifically designed around signatures intelligence
Operations, May 22, 2020.
and electronic warfare—alongside additional aviation
DOD Directive 3222.4 Electronic Warfare Policy, March 26,
programs, including the F-35B Lightning II aircraft.
2014, with Change 2, Effective August 31, 2018.
Another initiative outlined in the most recent Marine Corps’
concept is signature management, which aims to limit
emissions to prevent adversaries’ access to precise locations
John R. Hoehn, Analyst in Military Capabilities and
of about U.S. forces.
Programs
Navy
IF11118
The Navy has several new operational concepts it intends to
use to counter adversaries, including the Naval Integrated
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Defense Primer: Electronic Warfare
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