Defense Primer: Agile Combat Employment (ACE) Concept
link to page 1 
June 24, 2024
Defense Primer: Agile Combat Employment (ACE) Concept
To inform and shape its planning, the U.S. Air Force
(USAF) has developed an operational concept known as
Core Elements
Agile Combat Employment (ACE). According to the Air
In AFDN 1-21, the Air Force characterizes ACE as
Force, ACE is a “proactive and reactive operational scheme
consisting of “five core elements.” These are: (1) posture;
of maneuver” to enable U.S. forces to “increase
(2) command and control (C2); (3) movement and
survivability while generating combat power.”
maneuver; (4) protection; and (5) sustainment. The five
core elements enable ACE’s operational framework and are
Background
each discussed in brief below.
An operational concept is a broad idea intended to guide the
organization and employment of military forces. The Air
Posture. According to AFDN 1-21, “posture is intrinsically
Force describes ACE as a response to recent geostrategic
tied to all other elements. It is the starting point from which
developments, including post-Cold War changes to U.S.
subsequent actions take place.” It entails securing sites and
global posture, advances in adversaries’ weapons systems,
facilities (e.g., runways, parking areas), as well as pre-
and domestic fiscal and political constraints. DOD has also
positioning equipment and supplies, and distributing or
characterized ACE as part of its overall approach to
redistributing forces. For overseas locations, ACE posture
increased competition from Russia and China. Other
objectives may include negotiating access, basing, and
military services have developed similar concepts (e.g., the
overflight rights with foreign governments.
Army’s Multi-Domain Operations, the Navy’s Distributed
Maritime Operations, and the Marine Corps’ Expeditionary
Command and Control (C2). Compared to more
Advanced Basing Operations).
centralized planning paradigms, ACE may create more
complicated C2 requirements for U.S. personnel and
ACE Overview
weapons systems, particularly when operating from (or
The central idea of ACE is the distribution and dispersal of
moving between) contingency locations. AFDN 1-21
units and capabilities across multiple and varied sites. Air
highlights the importance of redundant and resilient C2
Force Doctrine Note 1-21 (AFDN 1-21)—the primary,
methods for ACE and the broader DOD Joint All Domain
fundamental explication of ACE that is publicly available—
Command and Control (JADC2) initiative is expected to
states that the concept “shifts operations from centralized
play a role in meeting ACE-specific C2 requirements.
physical infrastructures to a network of smaller, dispersed
locations that can complicate adversary planning and
Movement and Maneuver. According to AFDN 1-21,
provide more options for joint force commanders.” Some
ACE-specific movement and maneuver requirements may
analysts have characterized it as a “hub-and-spoke”
entail the “movement of forces to predetermined, dispersed
approach, with an enduring location (e.g., an existing U.S.
locations and flow of dispersed forces back to an enduring
or allied airbase) serving as a hub for a number of
location” before or during combat operations.
contingency locations (e.g., civilian airports, austere or
standalone airstrips), between which aircraft can be shifted
Protection. This element involves countering threats to
and from which missions can be launched (see Figure 1).
operating locations, personnel and weapons systems, and
logistical capabilities or assets. Protection, in the context of
Figure 1. Hub and Spoke
ACE, would vary by location, but may involve the
integration of both passive and active defenses to counter
threats in domains such as ground, sea, air, space, and
cyberspace.
Sustainment. The Air Force states that “sustainment plans
should focus primarily on aircraft sortie generation” but
should also include the ability to execute C2 and base
operating support functions, which include providing
maintenance, dining, lodging, and medical support to
forces.
Visualizing and Executing ACE
Source: CRS analysis of Air Force Doctrine Note 1-21, “Agile
Although the application of ACE may differ by mission set
Combat Employment,” August 23, 2022.
and location, in further explication of its doctrine, the Air
Force has offered help visualizing the ACE concept in
terms of five phases. The five phases may not be sequential
https://crsreports.congress.gov
link to page 2
Defense Primer: Agile Combat Employment (ACE) Concept
but provide a general framework for ACE operations and
that will work, train, and exercise together throughout the
incorporate and/or align with the ACE core elements
AFFORGEN cycle. ATFs then deploy together, ideally
allowing commanders flexibility and fluidity during
ready to operate as a team which may help prepare airmen
dynamic operations (see Figure 2).
to support the demands of ACE operations.
Figure 2. Visualizing ACE
Great Power Competition. In 2022, the Air Force
identified seven Department of the Air Force (DAF)
investment priorities, or “Operational Imperatives” (OIs)
necessary to maintain its “competitive” advantage against
peer threats like China. ACE is nested under the “Resilient
Basing” OI. The Air Force has announced plans to
“reoptimize for great power competition,” including by
restructuring unit organizations; conducting large-scale
exercises and ACE-specific training; revising processes to
ensure the availability of aviation spares and weapon
systems; emphasizing C2, communications, and “battle
management”; and creating new MCA training initiatives—
all of which may support the implementation of ACE. The
Air Force also continues to expand ally and partnership
Source: Information presented in Air University, “Visualizing Agile
agreements to secure access, basing, and overflight options
Combat Employment.”
and participates in exercises to increase integration and
In the first phase (“Setting the Theater”), the Air Force
foster partnerships.
identifies and prepares locations and equipment for use. In
the second phase (“Proactive ACE Maneuver”), the Air
Resourcing and Legislative Activity
Force positions and distributes personnel and assets to
The DAF FY2025 Presidential Budget request identifies
anticipate or influence adversary actions before they occur
$538 million for ACE, $400 million of which is requested
(as an example of this in practice, some Air Force officials
for line items in the Operation & Maintenance, Air Force
have pointed to Ukraine’s dispersal of aircraft immediately
account to “set the theater, provide agile communications,
prior to Russia’s 2022 invasion). The third phase (“Reactive
and develop mission-ready Airmen.” Other funding
ACE Maneuver”) is intended to respond to “observed,
requests may be found in Military Construction,
perceived, anticipated or realized enemy aggression,” and
Procurement, and Research and Development Air Force
may involve redistributing forces for optimal survivability.
accounts. The FY2025 DAF Unfunded Priority List
The fourth phase (“Joint Massing of Effects”) entails
includes $266.3 million “to execute theatre-wide Agile
coordinating the employment of combat assets (including
Combat Employment exercises.” The FY2025 Pacific
allied/partner forces) to maximize offensive impact across
Deterrence Initiative and the European Deterrence Initiative
all domains from dispersed locations. Finally, the fifth
request include ACE-related funding. Additionally, the
phase (“Recovery and Sustainment”) involves repairing
Senate Armed Services Committee report accompanying
equipment and infrastructure to continue generating combat
the FY2024 National Defense Authorization Act directs the
air power.
Air Force to report to the defense committees on various
aspects of ACE development and implementation.
Relationship to other Air Force Initiatives
Multi-Capable Airmen. The Air Force has identified its
Considerations for Congress
initiative to train and develop multi-capable airmen
Potential considerations for Congress regarding ACE
(MCAs) as a key enabler for ACE. MCAs are individuals
include (but are not necessarily limited to) the following:
trained in additional tasks outside their primary career field
•
(e.g., an MCA might work as an aircraft maintainer, but
Does ACE adequately support Congress’s assessment of
also be capable of providing security or communication
national strategic and operational priorities? In
Congress’
support). The Air Force intends to utilize small teams of
s view, is ACE appropriately aligned with
MCAs to reduce demands on servicemembers and
other services’ operational concepts and support
personnel, as well as increase agility. In the context of
requirements (e.g., Army base defense)?
ACE, MCAs may enable the execution of functions such as
•
C2, aircraft operations, and base support at austere locations
In Congress’s view, are DAF budgets and programs
with limited infrastructure and personnel.
appropriately resourced to implement ACE? Should
Congress increase, decrease, or keep constant relevant
Force Generation. In parallel with ACE development, the
Air Force appropriations?
Air Force is introducing new models for organizing,
•
training, and equipping forces to conduct ACE missions.
Are there political or diplomatic risks attendant on ACE
The new force generation model known as the Air Force
implementation, particularly given the role played by
Force Generation or AFFORGEN “establishes a more
bases and other infrastructure located in foreign
“structured and predictable cycle to better prepare Airmen
countries? In Congress’s view, are DAF and DOD
for distributed, high-end combat operations.” Additionally,
taking appropriate steps to ensure access would be
the Air Force is experimenting with Air Task Forces
granted under wartime circumstances?
(ATFs) to “generate more efficient integrated deployable
Units of Action.” ATFs package together teams of airmen
Sarah Gee, National Defense Fellow
https://crsreports.congress.gov
Defense Primer: Agile Combat Employment (ACE) Concept
IF12694
Luke A. Nicastro, Analyst in U.S. Defense Infrastructure
Policy
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 | IF12694 · VERSION 1 · NEW
June 24, 2024
Defense Primer: Agile Combat Employment (ACE) Concept
To inform and shape its planning, the U.S. Air Force
(USAF) has developed an operational concept known as
Core Elements
Agile Combat Employment (ACE). According to the Air
In AFDN 1-21, the Air Force characterizes ACE as
Force, ACE is a “proactive and reactive operational scheme
consisting of “five core elements.” These are: (1) posture;
of maneuver” to enable U.S. forces to “increase
(2) command and control (C2); (3) movement and
survivability while generating combat power.”
maneuver; (4) protection; and (5) sustainment. The five
core elements enable ACE’s operational framework and are
Background
each discussed in brief below.
An operational concept is a broad idea intended to guide the
organization and employment of military forces. The Air
Posture. According to AFDN 1-21, “posture is intrinsically
Force describes ACE as a response to recent geostrategic
tied to all other elements. It is the starting point from which
developments, including post-Cold War changes to U.S.
subsequent actions take place.” It entails securing sites and
global posture, advances in adversaries’ weapons systems,
facilities (e.g., runways, parking areas), as well as pre-
and domestic fiscal and political constraints. DOD has also
positioning equipment and supplies, and distributing or
characterized ACE as part of its overall approach to
redistributing forces. For overseas locations, ACE posture
increased competition from Russia and China. Other
objectives may include negotiating access, basing, and
military services have developed similar concepts (e.g., the
overflight rights with foreign governments.
Army’s Multi-Domain Operations, the Navy’s Distributed
Maritime Operations, and the Marine Corps’ Expeditionary
Command and Control (C2). Compared to more
Advanced Basing Operations).
centralized planning paradigms, ACE may create more
complicated C2 requirements for U.S. personnel and
ACE Overview
weapons systems, particularly when operating from (or
The central idea of ACE is the distribution and dispersal of
moving between) contingency locations. AFDN 1-21
units and capabilities across multiple and varied sites. Air
highlights the importance of redundant and resilient C2
Force Doctrine Note 1-21 (AFDN 1-21)—the primary,
methods for ACE and the broader DOD Joint All Domain
fundamental explication of ACE that is publicly available—
Command and Control (JADC2) initiative is expected to
states that the concept “shifts operations from centralized
play a role in meeting ACE-specific C2 requirements.
physical infrastructures to a network of smaller, dispersed
locations that can complicate adversary planning and
Movement and Maneuver. According to AFDN 1-21,
provide more options for joint force commanders.” Some
ACE-specific movement and maneuver requirements may
analysts have characterized it as a “hub-and-spoke”
entail the “movement of forces to predetermined, dispersed
approach, with an enduring location (e.g., an existing U.S.
locations and flow of dispersed forces back to an enduring
or allied airbase) serving as a hub for a number of
location” before or during combat operations.
contingency locations (e.g., civilian airports, austere or
standalone airstrips), between which aircraft can be shifted
Protection. This element involves countering threats to
and from which missions can be launched (see Figure 1).
operating locations, personnel and weapons systems, and
logistical capabilities or assets. Protection, in the context of
Figure 1. Hub and Spoke
ACE, would vary by location, but may involve the
integration of both passive and active defenses to counter
threats in domains such as ground, sea, air, space, and
cyberspace.
Sustainment. The Air Force states that “sustainment plans
should focus primarily on aircraft sortie generation” but
should also include the ability to execute C2 and base
operating support functions, which include providing
maintenance, dining, lodging, and medical support to
forces.
Visualizing and Executing ACE
Source: CRS analysis of Air Force Doctrine Note 1-21, “Agile
Although the application of ACE may differ by mission set
Combat Employment,” August 23, 2022.
and location, in further explication of its doctrine, the Air
Force has offered help visualizing the ACE concept in
terms of five phases. The five phases may not be sequential
https://crsreports.congress.gov
link to page 2
Defense Primer: Agile Combat Employment (ACE) Concept
but provide a general framework for ACE operations and
that will work, train, and exercise together throughout the
incorporate and/or align with the ACE core elements
AFFORGEN cycle. ATFs then deploy together, ideally
allowing commanders flexibility and fluidity during
ready to operate as a team which may help prepare airmen
dynamic operations (see Figure 2).
to support the demands of ACE operations.
Figure 2. Visualizing ACE
Great Power Competition. In 2022, the Air Force
identified seven Department of the Air Force (DAF)
investment priorities, or “Operational Imperatives” (OIs)
necessary to maintain its “competitive” advantage against
peer threats like China. ACE is nested under the “Resilient
Basing” OI. The Air Force has announced plans to
“reoptimize for great power competition,” including by
restructuring unit organizations; conducting large-scale
exercises and ACE-specific training; revising processes to
ensure the availability of aviation spares and weapon
systems; emphasizing C2, communications, and “battle
management”; and creating new MCA training initiatives—
all of which may support the implementation of ACE. The
Air Force also continues to expand ally and partnership
Source: Information presented in Air University, “Visualizing Agile
agreements to secure access, basing, and overflight options
Combat Employment.”
and participates in exercises to increase integration and
In the first phase (“Setting the Theater”), the Air Force
foster partnerships.
identifies and prepares locations and equipment for use. In
the second phase (“Proactive ACE Maneuver”), the Air
Resourcing and Legislative Activity
Force positions and distributes personnel and assets to
The DAF FY2025 Presidential Budget request identifies
anticipate or influence adversary actions before they occur
$538 million for ACE, $400 million of which is requested
(as an example of this in practice, some Air Force officials
for line items in the Operation & Maintenance, Air Force
have pointed to Ukraine’s dispersal of aircraft immediately
account to “set the theater, provide agile communications,
prior to Russia’s 2022 invasion). The third phase (“Reactive
and develop mission-ready Airmen.” Other funding
ACE Maneuver”) is intended to respond to “observed,
requests may be found in Military Construction,
perceived, anticipated or realized enemy aggression,” and
Procurement, and Research and Development Air Force
may involve redistributing forces for optimal survivability.
accounts. The FY2025 DAF Unfunded Priority List
The fourth phase (“Joint Massing of Effects”) entails
includes $266.3 million “to execute theatre-wide Agile
coordinating the employment of combat assets (including
Combat Employment exercises.” The FY2025 Pacific
allied/partner forces) to maximize offensive impact across
Deterrence Initiative and the European Deterrence Initiative
all domains from dispersed locations. Finally, the fifth
request include ACE-related funding. Additionally, the
phase (“Recovery and Sustainment”) involves repairing
Senate Armed Services Committee report accompanying
equipment and infrastructure to continue generating combat
the FY2024 National Defense Authorization Act directs the
air power.
Air Force to report to the defense committees on various
aspects of ACE development and implementation.
Relationship to other Air Force Initiatives
Multi-Capable Airmen. The Air Force has identified its
Considerations for Congress
initiative to train and develop multi-capable airmen
Potential considerations for Congress regarding ACE
(MCAs) as a key enabler for ACE. MCAs are individuals
include (but are not necessarily limited to) the following:
trained in additional tasks outside their primary career field
•
(e.g., an MCA might work as an aircraft maintainer, but
Does ACE adequately support Congress’s assessment of
also be capable of providing security or communication
national strategic and operational priorities? In
Congress’
support). The Air Force intends to utilize small teams of
s view, is ACE appropriately aligned with
MCAs to reduce demands on servicemembers and
other services’ operational concepts and support
personnel, as well as increase agility. In the context of
requirements (e.g., Army base defense)?
ACE, MCAs may enable the execution of functions such as
•
C2, aircraft operations, and base support at austere locations
In Congress’s view, are DAF budgets and programs
with limited infrastructure and personnel.
appropriately resourced to implement ACE? Should
Congress increase, decrease, or keep constant relevant
Force Generation. In parallel with ACE development, the
Air Force appropriations?
Air Force is introducing new models for organizing,
•
training, and equipping forces to conduct ACE missions.
Are there political or diplomatic risks attendant on ACE
The new force generation model known as the Air Force
implementation, particularly given the role played by
Force Generation or AFFORGEN “establishes a more
bases and other infrastructure located in foreign
“structured and predictable cycle to better prepare Airmen
countries? In Congress’s view, are DAF and DOD
for distributed, high-end combat operations.” Additionally,
taking appropriate steps to ensure access would be
the Air Force is experimenting with Air Task Forces
granted under wartime circumstances?
(ATFs) to “generate more efficient integrated deployable
Units of Action.” ATFs package together teams of airmen
Sarah Gee, National Defense Fellow
https://crsreports.congress.gov
Defense Primer: Agile Combat Employment (ACE) Concept
IF12694
Luke A. Nicastro, Analyst in U.S. Defense Infrastructure
Policy
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 | IF12694 · VERSION 1 · NEW