The President’s Authority to Use the National Guard or the Armed Forces to Secure the Border

The President’s Authority to Use the National Guard or the Armed Forces to Secure the Border

Legal Sidebari

The President’s Authority to Use the National
Guard or the Armed Forces to Secure the
Border
Updated June 15, 2023
On May 2, 2023, the Biden Administration announced that Secretary of Defense Lloyd Austin approved a
request from Secretary of Homeland Security Alejandro Mayorkas to send an additional 1,500 active-duty
members of the Armed Forces to assist U.S. Customs and Border Protection (CBP) agents with a potential
influx of migrants after pandemic-era health restrictions ended in May 2023. (This figure does not include
the thousands of Texas National Guard troops deployed to the border as part of Texas’s Operation Lone
Star.) The federal deployment is to last up to 90 days and add to the 2,500 National Guard members
already deployed to the border with Mexico. The Department of Defense (DOD) said the troops will
provide “ground-based detection and monitoring, data entry, and warehouse support” and will not
“directly participate in law enforcement activities.” This Sidebar addresses precedent for deploying troops
to the border and the President’s legal authorities to use the National Guard or the Armed Forces to assist
in securing the southwestern border.
Precedent
There is precedent for deploying National Guard units to the southwestern border to assist with
immigration control. President Trump deployed units there in April 2018 to “stop the flow of deadly
drugs and other contraband, gang members and other criminals, and illegal aliens” pursuant to Title 32
authority. (In “Title 32 status,” National Guard members remain under the control of the governors of
their home states and are not considered to be performing active-duty service as part of the regular Armed
Forces. Mobilization of National Guard members under Title 10 differs from mobilization under Title 32
in a number of ways.) President Trump also ordered the Pentagon to deploy active-duty troops to the
southwest border in October 2018. The Pentagon reportedly sent 5,800 soldiers to support the border
mission.
From 2006 to 2008, President George W. Bush called on the National Guard to participate in Operation
Jump Start, in which National Guard troops were called to duty to assist CBP to secure the southwestern
border. National Guard members participating in this operation did not serve in a direct law enforcement
role but rather reinforced the U.S. Border Patrol, including by performing missions involving
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engineering; aviation; entry identification teams; and a wide range of technical, logistical, and
administrative support. President Barack Obama used National Guard troops in a similar role in 2010
during Operation Phalanx, a successor operation to Operation Jump Start.
Authority to Deploy the National Guard
Section 502 of Title 32, U.S. Code, provides the authority for the Secretary of the Army and the Secretary
of the Air Force to call National Guard units to active duty under Title 32 status for training purposes. It
also permits individual members to be called to active duty to perform training “or other duty in addition
to” the mandatory training described earlier in Section 502. This is the provision of law that was used to
provide federal pay and benefits to the National Guard personnel who provided security at many of the
nation’s airports after September 11, 2001, and who participated in disaster relief operations in response
to hurricanes Katrina and Rita in 2005. Title 32 authority under Section 502(f) was also used for
Operation Jump Start and Operation Phalanx, discussed above. Although National Guard members did
not engage in direct law enforcement activities during these two border security operations, it is possible
that states might consider giving them that authority in future operations.
As a matter of statute, other duty under Section 502(f) may also include “homeland defense activities.”
Such activities are statutorily defined to mean activities
undertaken for the military protection of the territory or domestic population of the United States,
or of infrastructure or other assets of the United States determined by the Secretary of Defense as
being critical to national security, from a threat or aggression against the United States.
Federal funding for some aspects of Title 32 missions may be available upon a determination by the
Secretary of Defense that the participation of National Guard units or members for a qualifying operation
is necessary and appropriate. The governor of a state wishing to use its National Guard resources for
homeland defense activities may also request funding assistance.
There is also a provision for ordering National Guard troops to duty for drug interdiction operations at the
state level. Federal funding may be provided to a state for the implementation of a drug interdiction
program in accordance with 32 U.S.C. § 112. Under this provision, the Secretary of Defense may grant
funding to the governor of a state who submits a “drug interdiction and counterdrug activities plan” that
satisfies certain statutory requirements. The Secretary of Defense is responsible for examining the
sufficiency of the drug interdiction plan and determining whether the distribution of funds for its
implementation would be proper. It appears that a state plan might include border security and
immigration-related functions that overlap with drug interdiction activities.
Authority to Deploy the Armed Forces
In the event regular Armed Forces are used to assist in securing the border, a number of legal
considerations may arise. For example, the use of the military to enforce immigration or criminal laws at
the border could run afoul of the Posse Comitatus Act, unless an exception applies. The Posse Comitatus
Act is a criminal prohibition that provides the following:
Whoever, except in cases and under circumstances expressly authorized by the Constitution or Act
of Congress, willfully uses any part of the Army, the Navy, the Marine Corps, the Air Force, or the
Space Force as a posse comitatus or otherwise to execute the laws shall be fined under this title or
imprisoned not more than two years, or both.
Consequently, there must be constitutional or statutory authority to use federal troops in a law
enforcement capacity to stop aliens from entering the country unlawfully, apprehend gang members, or
seize contraband. (The Posse Comitatus Act does not apply to the National Guard unless it is activated for
federal service.)

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The Constitution empowers Congress to authorize the militia to be called forth to execute federal law.
Congress has used this power to authorize the President to use the regular Armed Forces and the National
Guard in cases of insurrection against state governments, obstruction of federal laws, or protecting civil
rights. These authorities permit the use of federal Armed Forces to execute a law enforcement role
notwithstanding the Posse Comitatus Act. It also seems well settled that the President has the
constitutional authority as commander in chief to employ the Armed Forces to defend against an armed
attack against the United States, its territories, or Armed Forces.
The Armed Forces do not appear to have a direct legislative mandate to protect or patrol the border or to
engage in immigration enforcement. Chapter 15 of Title 10, U.S. Code—Military Support for Civilian
Law Enforcement Agencies, however, provides general legislative authority for the Armed Forces to
provide certain types of support to federal, state, and local law enforcement agencies and, in particular, to
assist in counterdrug and counterterrorism efforts. Such authorities might permit the military to provide
indirect border security and immigration control assistance. These authorities permit DOD to share
information collected during the normal course of military operations, loan equipment and facilities,
provide expert advice and training, and maintain such equipment. For federal law enforcement agencies,
military personnel may be made available to maintain and operate equipment in conjunction with
counterterrorism operations or the enforcement of counterdrug laws, immigration laws, and customs
requirements. Military personnel are permitted under this authority to maintain and operate equipment
only for specific purposes, including aerial reconnaissance and the detection, monitoring, and
communication of the movement of air and sea traffic and of surface traffic outside the United States or
within 25 miles of U.S. borders if first detected outside the border.
Congress placed several stipulations on Chapter 15 assistance. For example, the recipient law
enforcement agency must reimburse DOD for the support it provides unless the support “is provided in
the normal course of military training or operations” or if it “results in a benefit ... substantially equivalent
to that which would otherwise be obtained from military operations or training.” DOD can also provide
such assistance only where it does not adversely affect “the military preparedness of the United States.”
Moreover, Congress incorporated posse comitatus restrictions into Chapter 15 support activities,
providing that the authorized assistance “does not include or permit direct participation by a member of
the Army, Navy, Air Force, or Marine Corps in a search, seizure, arrest, or other similar activity unless
participation in such activity by such member is otherwise authorized by law.”
With respect to counterdrug operations and activities to counter other transnational crimes along the
border, beginning in 1989, Congress expanded the military’s support role in a number of other ways. For
example, Congress directed DOD, to the maximum extent practicable, to conduct military training
exercises in drug interdiction areas and made DOD the lead federal agency for the detection and
monitoring of aerial and maritime transit of illegal drugs into the United States. Congress later provided
additional authorities for military support to law enforcement agencies specifically for counterdrug
purposes in the National Defense Authorization Act for FY1991. Section 1004 of the law authorized DOD
to extend support in several areas to any federal, state, and local (and sometimes foreign) law enforcement
agency requesting counterdrug assistance, subject to restrictions against military direct participation in
law enforcement. This section was extended a number of times but was repealed at the end of 2016, when
it was superseded by similar authority now codified at 10 U.S.C. § 284 to provide assistance in drug
interdiction and activities to control transnational organized crime. The authorized assistance is limited to
maintenance or upgrade of equipment, transportation of personnel, establishment and operation of
operations or training bases, training of law enforcement personnel, detecting and monitoring traffic
within 25 miles of the border, constructing roads and fences, installing lights along smuggling corridors,
establishing command and control centers and computer networks, providing linguist and intelligence
analysis services, and conducting aerial and ground reconnaissance.

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As noted, these Chapter 15 authorities restrict military personnel from participating directly in law
enforcement activities, but military reconnaissance patrols along the border may be armed and permitted
to fire in self-defense under applicable rules governing the use of force. Controversy arose in 1997 after a
group of U.S. Marines conducting drug interdiction surveillance fired upon and killed an American
teenage goatherd they believed posed a threat.

Author Information

Jennifer K. Elsea

Legislative Attorney

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