https://crsreports.congress.gov
Updated November 14, 2022
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 anti-
access/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.
