Updated November 17, 2021
Defense Primer: U.S. Policy on Lethal Autonomous
Weapon Systems
Lethal autonomous weapon systems (LAWS) are a special
weapons, such as certain types of guided missiles, that
class of weapon systems that use sensor suites and
deliver effects to human-identified targets using
computer algorithms to independently identify a target and
autonomous functions.
employ an onboard weapon system to engage and destroy
the target without manual human control of the system.
The directive does not cover “autonomous or semi-
Although these systems are not yet in widespread
autonomous cyberspace systems for cyberspace operations;
development, it is believed they would enable military
unarmed, unmanned platforms; unguided munitions;
operations in communications-degraded or -denied
munitions manually guided by the operator (e.g., laser- or
environments in which traditional systems may not be able
wire-guided munitions); mines; [and] unexploded explosive
to operate.
ordnance,” nor subject them to its guidelines.
Contrary to a number of news reports, U.S. policy does not
Role of human operator. DODD 3000.09 requires that all
prohibit the development or employment of LAWS.
systems, including LAWS, be designed to “allow
Although the United States does not currently have LAWS
commanders and operators to exercise appropriate levels of
in its inventory, some senior military and defense leaders
human judgment over the use of force.” As noted in an
have stated that the United States may be compelled to
August 2018 U.S. government white paper, “‘appropriate’
develop LAWS in the future if U.S. competitors choose to
is a flexible term that reflects the fact that there is not a
do so. At the same time, a growing number of states and
fixed, one-size-fits-all level of human judgment that should
nongovernmental organizations are appealing to the
be applied to every context. What is ‘appropriate’ can differ
international community for regulation of or a ban on
across weapon systems, domains of warfare, types of
LAWS due to ethical concerns.
warfare, operational contexts, and even across different
functions in a weapon system.”
Developments in both autonomous weapons technology and
international discussions of LAWS could hold implications
Furthermore, “human judgment over the use of force” does
for congressional oversight, defense investments, military
not require manual human “control” of the weapon system,
concepts of operations, treaty-making, and the future of
as is often reported, but rather broader human involvement
war.
in decisions about how, when, where, and why the weapon
will be employed. This includes a human determination that
U.S. Policy
the weapon will be used “with appropriate care and in
Definitions. There is no agreed definition of lethal
accordance with the law of war, applicable treaties, weapon
autonomous weapon systems that is used in international
system safety rules, and applicable rules of engagement.”
fora. However, Department of Defense Directive (DODD)
3000.09 (the directive), which establishes U.S. policy on
To aid this determination, DODD 3000.09 requires that
autonomy in weapons systems, provides definitions for
“[a]dequate training, [tactics, techniques, and procedures],
different categories of autonomous weapon systems for the
and doctrine are available, periodically reviewed, and used
purposes of the U.S. military. These definitions are
by system operators and commanders to understand the
principally grounded in the role of the human operator with
functioning, capabilities, and limitations of the system’s
regard to target selection and engagement decisions, rather
autonomy in realistic operational conditions.” The directive
than in the technological sophistication of the weapon
also requires that the weapon’s human-machine interface be
system.
“readily understandable to trained operators” so they can
make informed decisions regarding the weapon’s use.
DODD 3000.09 defines LAWS as “weapon system[s] that,
once activated, can select and engage targets without
Weapons review process. DODD 3000.09 requires that the
further intervention by a human operator.” This concept of
software and hardware of all systems, including lethal
autonomy is also known as “human out of the loop” or “full
autonomous weapons, be tested and evaluated to ensure
autonomy.” The directive contrasts LAWS with human-
they
supervised, or “human on the loop,” autonomous weapon
systems, in which operators have the ability to monitor and
Function as anticipated in realistic operational
halt a weapon’s target engagement. Another category is
environments
against
adaptive
adversaries;
semi-autonomous, or “human in the loop,” weapon systems
complete engagements in a timeframe consistent
that “only engage individual targets or specific target
with commander and operator intentions and, if
groups that have been selected by a human operator.” Semi-
unable to do so, terminate engagements or seek
autonomous weapons include so-called “fire and forget”
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Defense Primer: U.S. Policy on Lethal Autonomous Weapon Systems
additional human operator input before continuing
Although the UN CCW is a consensus-based forum, the
the engagement; and are sufficiently robust to
outcome of its discussions could hold implications for U.S.
minimize failures that could lead to unintended
policy on lethal autonomous weapons.
engagements or to loss of control of the system to
Potential Questions for Congress
unauthorized parties.
 To what extent are potential U.S. adversaries developing
LAWS?
Any changes to the system’s operating state—for example,
 How should the United States balance LAWS research
due to machine learning—would require the system to go
and development with ethical considerations?
through testing and evaluation again to ensure that it has
 What role should the United States play in UN CCW
retained its safety features and ability to operate as
discussions of LAWS? Should the United States support
intended.
the status quo, propose a political declaration, or
advocate regulation of or a ban on LAWS?
Senior-level review. In addition to the standard weapons
 If the United States chooses to develop LAWS, are
review process, a secondary senior-level review is required
current weapons review processes and legal standards
for LAWS and certain types of semi-autonomous and
for their employment in conflict sufficient?
human-supervised autonomous weapons that deliver lethal
effects. This review requires the Under Secretary of
CRS Products
Defense for Policy, the Chairman of the Joint Chiefs of
Staff, and either the Under Secretary of Defense for
CRS Report R44466, Lethal Autonomous Weapon Systems:
Acquisition and Sustainment or the Under Secretary of
Issues for Congress, by Nathan J. Lucas.
Defense for Research and Engineering to approve the
CRS In Focus IF11294, International Discussions Concerning
system “before formal development and again before
Lethal Autonomous Weapon Systems, by Kelley M. Sayler.
fielding in accordance with the guidelines” listed in
CRS Report R45178, Artificial Intelligence and National Security,
Enclosure 3 of the directive. In the event of “urgent military
by Kelley M. Sayler.
operational need,” this senior-level review may be waived
by the Deputy Secretary of Defense “with the exception of
CRS Report R45392, U.S. Ground Forces Robotics and
the requirement for a legal review.” DOD is reportedly in
Autonomous Systems (RAS) and Artificial Intelligence (AI):
the process of developing a handbook to guide senior
Considerations for Congress, coordinated by Andrew Feickert.
leaders through this review process; however, as the United
States is not currently developing LAWS, no weapon
Other Resources
system has gone through the senior-level review process to
Department of Defense Directive 3000.09, “Autonomy in
date.
Weapon Systems,” Updated May 8, 2017,
https://www.esd.whs.mil/portals/54/documents/dd/issuances/
International Discussions of LAWS
dodd/300009p.pdf.
Since 2014, the United States has participated in
international discussions of LAWS, sometimes colloquially
U.S. Government, “Humanitarian Benefits of Emerging
referred to as “killer robots,” under the auspices of the
Technologies in the Area of Lethal Autonomous Weapons,”
United Nations Convention on Certain Conventional
March 28, 2018,
Weapons (UN CCW). In 2017, these discussions
https://www.unog.ch/80256EDD006B8954/(httpAssets)/7C177
transitioned from an informal “meeting of experts” to a
AE5BC10B588C125825F004B06BE/$file/CCW_GGE.1_2018_
formal “Group of Governmental Experts” (GGE) tasked
WP.4.pdf.
with examining the technological, military, ethical, and
U.S. Government, “Human-Machine Interaction in the
legal dimensions of LAWS. In 2018 and 2019, the GGE has
Development, Deployment and Use of Emerging Technologies
considered proposals by states parties to issue political
in the Area of Lethal Autonomous Weapons Systems,” August
declarations about LAWS, as well as proposals to regulate
28, 2018,
them.
https://www.unog.ch/80256EDD006B8954/(httpAssets)/D1A2
BA4B7B71D29FC12582F6004386EF/$file/2018_GGE+LAWS_
In addition, approximately 30 countries and 165
August_Working+Paper_US.pdf.
nongovernmental organizations have called for a
United Nations Office at Geneva, “Background on Lethal
preemptive ban on LAWS due to ethical concerns,
Autonomous Weapons Systems in the CCW,”
including concerns about operational risk, accountability
https://www.unog.ch/80256EE600585943/(httpPages)/8FA3C2
for use, and compliance with the proportionality and
562A60FF81C1257CE600393DF6?OpenDocument.
distinction requirements of the law of war. The U.S.
Defense Innovation Board, “AI Principles: Recommendations
government does not currently support a ban on LAWS and
on the Ethical Use of Artificial Intelligence by the Department
has addressed ethical concerns about the systems in a
of Defense,” October 2019.
March 2018 white paper, “Humanitarian Benefits of
Emerging Technologies in the Area of Lethal Autonomous

Weapons.” The paper notes that “automated target
identification, tracking, selection, and engagement
functions can allow weapons to strike military objectives
Kelley M. Sayler, Analyst in Advanced Technology and
more accurately and with less risk of collateral damage” or
Global Security
civilian casualties.
IF11150
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Defense Primer: U.S. Policy on Lethal Autonomous Weapon Systems


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