link to page 1


February 24, 2021
Integrated Air Defense Systems (IADS) and Military Ranges
For as long as aerial warfare has existed, the continual
What is a Modern IADS?
expansion of offensive air and missile weapons capabilities
Potential adversaries like Iran, Russia, and China have
has led militaries to develop commensurate defensive
identified airpower as a primary U.S. advantage in military
capabilities. These “air defense systems” (also called “air
operations. As a result, several of these nations have
and missile defense” (AMD) systems) provide surveillance,
developed sophisticated IADS to counter U.S. military
tracking, command and control, and weapons delivery
capabilities. This includes networking multiple types of
capabilities to battlefield commanders. Historically, AMD
ground–based radars (e.g., long-range surveillance radar,
systems were independently operated and managed by each
engagement radar) with mobile command posts and air and
military service. Gradually, they became more connected,
space-based capabilities to provide a larger, and more
and today several of these systems can communicate and
comprehensive, picture of the battlespace (Figure 1). This
operate collectively. This is basis for the concept of an
creates a challenge for U.S. forces because there is no
integrated air defense system, or IADS. According to the
single sensor or missile to neutralize, but rather a
Department of Defense (DOD), an “IADS is not a formal
distributed network to contend with.
system in itself, but the aggregate of Service / functional
Figure 1. How a Modern IADS Functions
component and agency AMD systems.”
Considered part of what DOD terms “defensive counterair”
(DCA), an IADS’ purpose is to protect military assets and
vital locations from aerial threats. Conversely, countering
an enemy’s IADS by destroying, suppressing, or otherwise
neutralizing their system is part of what DOD defines as
“offensive counterair” (OCA). The U.S. military tests and
trains to effectively employ an IADS as well as counter an
enemy’s IADS. Training for and conducting DCA and
OCA activities typically requires a significant amount of air
and ground space, along with access to, and control of, the
associated electromagnetic spectrum (see CRS In Focus
IF11155, Defense Primer: Military Use of the
Electromagnetic Spectrum, by John R. Hoehn).
Military “ranges”—defined under 10 U.S.C. §101(e)—that
support IADS generally correspond to large-scale ranges

used for aviation training. These ranges have the required
Source: Adapted from Royal United Services Institute for Defence and
land, defined airspace (called a “military operations area”
Security Studies report titled “Modern Russian and Chinese Integrated
or MOA), and when necessary sea space, available to
Air Defence Systems,” January 2020.
employ multiple AMD systems.
Additionally, advances in U.S. and foreign technologies—
DOD states that several of these ranges are now regularly
particularly in microelectronics and processing power—
operating at full capacity to support numerous types of
have significantly increased the ranges IADS are able to
military units from across the joint force (e.g., aviation
surveil, track, and engage targets. These are the “modern
units, marine amphibious forces, special operations forces).
IADS” capabilities U.S. forces employ; they are also the
At some locations, non-DOD federal agencies and coalition
modern IADS threats U.S. forces face.
partners also make use of these ranges. This has presented a
capacity challenge for the Military Services who schedule
Selected Foreign IADS Capabilities
and manage range use. Further exacerbating the issue, DOD
For over 10 years, Russia and China have developed
asserts that recent technology increases in IADS
sophisticated anti-access/area denial (A2/AD) systems in an
capabilities have necessitated an increase in testing and
attempt to prevent U.S. forces from accessing certain areas
training space (i.e., range size). This has led DOD to
and regions. Capabilities of A2/AD systems—which
request from Congress expansion of, and in some cases
include IADS—continue to increase, consequently
additional access to, certain ranges that could support
increasing the distance from which U.S. forces must operate
“modern IADS” testing and training—along with several
to avoid detection and potential harm.
other readiness requirements.
One of the most challenging foreign IADS capabilities that
Congress faces the issue of addressing DOD’s request for
U.S. forces may encounter is the Russian developed S-400
additional range space and access at certain locations, as
missile system (SA-21 Growler). This weapons system uses
DOD seeks to fully train for advances in IADS.
radars with ranges of up to 400 kilometers (~250 miles),
paired with missiles that can reach similar distances. An
https://crsreports.congress.gov
link to page 2
Integrated Air Defense Systems (IADS) and Military Ranges
adversary would not necessarily launch a missile to its
Figure 2. Example Range Overlay of a Peer IADS
maximum range to engage a target, but this capacity allows
for additional maneuverability within 250 miles to more
effectively engage targets.
The Chinese HQ-9 surface-to-air missile system, and its
naval variant the HHQ-9 series, pose similar challenges. It’s
reported that these systems were developed in China and
have radar ranges of up to 200 kilometers (~125 miles) with
missile ranges of around 125 kilometers (~78 miles). China
also has been improving versions of the HQ-9, such as the
HQ-19 ballistic missile interceptor, intended to reach
targets up to 3000 kilometers (~1865 miles).
Selected DOD Programs Linked to IADS
DOD has developed a number of capabilities that support
and counter IADS. These include “stealth” (i.e., low
observable) technology, long-range missiles, and radar
jamming equipment. Examples of air-based platforms and
weapons systems that include IADS technologies are:

Source: U.S. Air Force, Final Legislative Environmental Impact
 F-35 Lightning II
Statement (FLEIS), Nevada Test and Training Range (NTTR) Land

Withdrawal, October 2018.
EA-18 Growler (incl. “Next Generation Jammer”)

Note: Figure is theoretical and not representative of any Air Force
B-2 Spirit

land withdrawal request included as part of the 2018 NTTR FLEIS.
AGM-158 Joint Air-to-Surface Standoff Missile
 AGM-88E Advanced Anti-Radiation Guided Missile
Considerations for Congress
Annual defense authorization and appropriations acts,
The Army and Marine Corps also maintain a number of
including the Military Construction, Veterans Affairs, and
ground-based platforms and systems used in U.S. IADS,
Related Agencies Appropriations Act, provide opportunities
such as the Avenger Air Defense System. They also have
for Congress to fund and shape defense programs for both
begun developing long-range precision fires to support the
IADS and military ranges. Enacting federal real property
Joint force in countering adversary IADS. These include the
transactions (e.g., land conveyances, exchanges, transfers)
strategic long-range cannon and the precision strike missile.
and setting the terms for federal land withdrawals are also
IADS Range Requirements
actions Congress could take to address those IADS-related
range challenges DOD has reported.
The Air Force states that modern combat operations are
Land Withdrawals. A periodically recurring role of
characterized by a wide battlespace that includes a
Congress is to assess the need for, and set the terms of,
simulated IADS, incorporating early warning radars,
federal land withdrawals (see CRS Report R46657,
strategic and tactical surface-to-air missile systems, fixed
Withdrawal of Federal Lands: Analysis of a Common
military-type targets, and friendly ground forces postured
Legislated Withdrawal Provision, by Carol Hardy
against organized enemy military ground forces.
Vincent and Erin H. Ward). This includes renewing
Replicating this setting at military ranges for the testing and
expiring land withdrawals—a process which can involve
training of IADS requires a certain amount of assets and
redefining the spatial boundaries of withdrawn lands.
infrastructure (e.g., buildings, vehicles, aircraft, sensors), as
Technological Advancement and Virtual Training.
well as the space to position and maneuver those assets to
Advancements in IADS’ capabilities increase the
match modern capabilities. An example of the extent of a
physical space required to fully conduct live training. At
“peer IADS” with a size and configuration that reflects “an
the same time, technological advancements in
actual relevant geopolitical area that the U.S. warfighter
virtual/mixed training environments (e.g., Live, Virtual,
might engage” is provided in Figure 2. The sheer size of
Constructive (LVC) technology) allow, to a certain
this theoretical example—paired with existing range
degree, virtual training space to substitute for physical
configurations and land use restrictions—suggests that
space. Congress may request DOD examine the extent
DOD may be limited in its ability to test and train today’s
to which virtual training environments could potentially
IADS at military ranges.
reduce physical space requirements for IADS training.
CRS Products
Other Resources
CRS Report R46463, U.S. Army Short-Range Air Defense Force
Joint Publication 3-01, Countering Air and Missile Threats
Structure and Selected Programs: Background and Issues for
Department of Defense 2019 Missile Defense Review
Congress, by Andrew Feickert

CRS Report R44572, U.S. Airborne Electronic Attack Programs:
Background and Issues for Congress, by John R. Hoehn
John R. Hoehn, Analyst in Military Capabilities and
Programs

https://crsreports.congress.gov
Integrated Air Defense Systems (IADS) and Military Ranges

IF11771
G. James Herrera, Analyst in U.S. Defense Readiness and
Infrastructure


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 | IF11771 · VERSION 1 · NEW