ȱ
‘ŽȱœŽȱ˜ȱŽŽ›Š•ȱ›˜˜™œȱ˜›ȱ’œŠœŽ›ȱ
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ǯȱ‘žŒ”ȱŠœ˜—ȱ
Ž’œ•Š’ŸŽȱ˜›—Ž¢ȱ
˜ŸŽ–‹Ž›ȱŘŞǰȱŘŖŖŞȱ
˜—›Žœœ’˜—Š•ȱŽœŽŠ›Œ‘ȱŽ›Ÿ’ŒŽȱ
ŝȬśŝŖŖȱ
   ǯŒ›œǯ˜Ÿȱ
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Pr
epared for Members and Committees of Congress

‘ŽȱœŽȱ˜ȱŽŽ›Š•ȱ›˜˜™œȱ˜›ȱ’œŠœŽ›ȱœœ’œŠ—ŒŽDZȱŽŠ•ȱ œœžŽœȱ
ȱ
ž––Š›¢ȱ
Natural disasters, such as Hurricane Katrina, raise questions concerning the President’s legal
authority to send active duty military forces into a disaster area and the permissible functions the
military can perform to protect life and property and maintain order. The Stafford Act authorizes
the use of the military for disaster relief operations at the request of the state governor, but it does
not authorize the use of the military to perform law enforcement functions, which is ordinarily
prohibited by the Posse Comitatus Act. However, the President may invoke other authorities to
use federal troops to aid in the execution of the law, including the Insurrection Act. This report
summarizes the possible constitutional and statutory authorities and constraints relevant to the use
of armed forces, including National Guard units in federal service, to provide assistance to states
when a natural disaster impedes the operation of state and local police.
˜—›Žœœ’˜—Š•ȱŽœŽŠ›Œ‘ȱŽ›Ÿ’ŒŽȱ

‘ŽȱœŽȱ˜ȱŽŽ›Š•ȱ›˜˜™œȱ˜›ȱ’œŠœŽ›ȱœœ’œŠ—ŒŽDZȱŽŠ•ȱ œœžŽœȱ
ȱ
˜—Ž—œȱ
The Posse Comitatus Act................................................................................................................. 1
Statutory Exceptions ................................................................................................................. 2
Enforcement of the Laws to Restore Public Order (the Insurrection Act) .......................... 2
Military Support for Law Enforcement Agencies............................................................... 3
Inherent Emergency Power ....................................................................................................... 3
The Stafford Act .............................................................................................................................. 4
Essential Assistance (10-Day Authority)................................................................................... 4
Emergency................................................................................................................................. 4
Major Disaster........................................................................................................................... 5
Immediate Response Authority ................................................................................................. 5

˜—ŠŒœȱ
Author Contact Information ............................................................................................................ 6

˜—›Žœœ’˜—Š•ȱŽœŽŠ›Œ‘ȱŽ›Ÿ’ŒŽȱ

‘ŽȱœŽȱ˜ȱŽŽ›Š•ȱ›˜˜™œȱ˜›ȱ’œŠœŽ›ȱœœ’œŠ—ŒŽDZȱŽŠ•ȱ œœžŽœȱ
ȱ
ecognizing the risk that a standing army could pose to individual civil liberties and the
sovereignty retained by the several states, but also cognizant of the need to provide for the
R defense of the nation against foreign and domestic threats, the framers of the Constitution
incorporated a system of checks and balances to divide the control of the military between the
President and Congress and to share the control of the militia with the states. This report
summarizes the constitutional and statutory authorities and limitations relevant to the
employment of the armed forces to provide disaster relief and law enforcement assistance.
Congress has the constitutional power to raise, support, organize and regulate the armed forces,
art. I, § 8, cls. 11-14. These clauses do not expressly limit Congress as to how, when, or where it
might employ the armed forces, although presumably such use must be in furtherance of other
constitutional powers. Congress is also empowered to provide for calling forth the militia to
execute federal law and to suppress insurrections, § 8, cl. 15, and to provide for organizing,
arming, and disciplining the militia and to govern them when they are employed in the service of
the United States, § 8, cl. 16. Once the army is raised or the militia called forth, the President
serves as their Commander-in-Chief, art. II, § 2, cl. 1. And of course, the President is vested with
the responsibility to “take Care that the Laws be faithfully executed,” art. II, § 2, cl. 3. Congress
has delegated to the President the authority to use the armed forces to respond to a variety of
domestic crises, and Presidents have asserted some inherent authority to use the military even
without express statutory authorization.
Under the Constitution, states retain the primary responsibility and authority to provide for civil
order and the protection of their citizens’ lives and property. However, the Constitution provides
that the federal government is responsible for protecting the states against invasion and
insurrection, and, if the state legislature (or the governor, if the legislature cannot be convened)
requests it, protection against “domestic Violence,” art. IV, § 4. States may not keep their own
standing armies, art. I, § 10, cl. 3, but they retain the authority to call forth their militias to
suppress insurrections or quell civil disturbances, subject to any restraints imposed by the
Constitution or by Congress, in the exercise of its constitutional powers. Congress has complete
authority over federal lands, military installations, and similar areas, art. I, § 8, cl. 17.
‘Žȱ˜œœŽȱ˜–’ŠžœȱŒȱ
The Constitution does not explicitly bar the use of military forces in civilian situations or in
matters of law enforcement, but the United States has traditionally refrained from employing
troops to enforce the law except in cases of necessity. The Posse Comitatus Act (PCA), 18 U.S.C.
§ 1385, punishes those who, “except in cases and under circumstances expressly authorized by
the Constitution or Act of Congress, willfully use[] any part of the Army or the Air Force as a
posse comitatus or otherwise to execute the laws.... ”1 The Act does not apply to the Navy or
Marines2 and does not prohibit activities conducted for a military purpose (base security or
enforcement of military discipline) that incidentally benefit civilian law enforcement bodies. The
Act does not apply to the National Guard unless it is employed in federal service. Questions arise
most often in the context of assistance to civilian police. At least in this context, the courts have

1 See CRS Report 95-964, The Posse Comitatus Act & Related Matters: The Use of the Military to Execute Civilian
Law
, by Charles Doyle.
2 Department of Defense regulations effectively place them under similar constraints, and the limitations on assistance
to civilian law enforcement authorities apply to them, 10 U.S.C. § 375.
˜—›Žœœ’˜—Š•ȱŽœŽŠ›Œ‘ȱŽ›Ÿ’ŒŽȱ
ŗȱ

‘ŽȱœŽȱ˜ȱŽŽ›Š•ȱ›˜˜™œȱ˜›ȱ’œŠœŽ›ȱœœ’œŠ—ŒŽDZȱŽŠ•ȱ œœžŽœȱ
ȱ
held that, absent a recognized exception, the PCA is violated (1) when civilian law enforcement
officials make “direct active use” of military investigators, (2) when the use of the military
“pervades the activities” of the civilian officials, or (3) when the military is used so as to subject
citizens to the exercise of military power that is “regulatory, prescriptive, or compulsory in
nature.”
Šž˜›¢ȱ¡ŒŽ™’˜—œȱ
Congress has provided for a number of statutory exceptions to the PCA by explicitly vesting law
enforcement authority either directly in a military branch (e.g, the Coast Guard) or indirectly by
authorizing the President or another government agency to call for assistance in enforcing certain
laws.3
—˜›ŒŽ–Ž—ȱ˜ȱ‘ŽȱŠ œȱ˜ȱŽœ˜›Žȱž‹•’Œȱ›Ž›ȱǻ‘Žȱ —œž››ŽŒ’˜—ȱŒǼȱ
Congress has delegated authority to the President to call forth the military during an insurrection
or civil disturbance, 10 U.S.C. §§ 331-335.4 Section 331 authorizes the President to use the
military to suppress an insurrection at the request of a state government, which is meant to fulfill
the federal government’s responsibility to protect states against “domestic violence” (although the
term “insurrection” is arguably much narrower than the phrase “domestic violence”). Section 332
delegates Congress’s power under the Constitution, art. I, § 8, cl. 14, to the President, authorizing
him to determine that “unlawful obstructions, combinations, or assemblages, or rebellion against
the authority of the United States make it impracticable to enforce the laws of the United States”
and to use the armed forces as he considers necessary to enforce the law or to suppress the
rebellion. Section 333 permits the President to use the armed forces to suppress any “insurrection,
domestic violence, unlawful combination, or conspiracy” if law enforcement is hindered within a
state, and local law enforcement is unable to protect individuals, or if the unlawful action
“obstructs the execution of the laws of the United States or impedes the course of justice under
those laws.” This section was enacted to implement the Fourteenth Amendment and does not
require the request or even the permission of the governor of the affected state.
The Insurrection Act has been used been used to send the armed forces to quell civil disturbances
a number of times during U.S. history, most recently during the 1992 Los Angeles riots and
during Hurricane Hugo in 1989, during which widespread looting was reported in St. Croix,
Virgin Islands. If the President decides to respond to such a situation, generally upon the

3 For a list of these authorities, see CRS Report 95-964, The Posse Comitatus Act & Related Matters: The Use of the
Military to Execute Civilian Law
, at ns. 63-64.
4 In 2007, the 109th Congress amended 10 U.S.C. § 333 to authorize the President to employ federal troops to “restore
public order and enforce the laws of the United States,” without a request from the governor or legislature of the state
involved, in the event that he determined that local authorities were unable to maintain public order. The expanded
authority was contingent on the enjoyment of equal protection of the laws being impeded or on the obstruction of the
execution of federal law and related judicial process (P.L. 109-364, 120 Stat. 2404, (October 17, 2006)). During the
110th Congress, Senator Patrick Leahy stated, while introducing S. 513 as an attempt to repeal the expanded authority,
that it had been added at the request of the Administration as a rider to the FY2007 Defense Authorization and that it
was “made without consulting the other relevant policy committees in the Senate and the House.” (Cong. Rec. S1712
(daily ed. February 7, 2007). Language was subsequently added to the FY2008 Defense Authorization bill repealing the
expanded authority (P.L. 110-181, 122 Stat. 325 (January 28, 2008)); returning the Insurrection Act to what had been in
effect prior to the FY2007 Defense Authorization bill and returning the authority to utilize the National Guard, during
domestic emergencies, to the state governors.
˜—›Žœœ’˜—Š•ȱŽœŽŠ›Œ‘ȱŽ›Ÿ’ŒŽȱ
Řȱ

‘ŽȱœŽȱ˜ȱŽŽ›Š•ȱ›˜˜™œȱ˜›ȱ’œŠœŽ›ȱœœ’œŠ—ŒŽDZȱŽŠ•ȱ œœžŽœȱ
ȱ
recommendation of the Attorney General and, if necessary, the request of the governor, he must
first issue a proclamation ordering the insurgents to disperse within a limited time, 10 U.S.C. §
334.5 If the situation does not resolve itself, the President may issue an executive order to send in
troops.6
’•’Š›¢ȱž™™˜›ȱ˜›ȱŠ ȱ—˜›ŒŽ–Ž—ȱŽ—Œ’Žœȱ
Congress has also authorized the armed forces to share information and equipment with civilian
law enforcement agencies, 10 U.S.C. §§ 371-382, although prohibiting the use of armed forces
personnel to make arrests or conduct searches and seizures.
—‘Ž›Ž—ȱ–Ž›Ž—Œ¢ȱ˜ Ž›ȱ
Department of Defense (DOD) regulations assert another exception that does not rest on statutory
authority, but is available in very limited circumstances and covers
Actions that are taken under the inherent right of the U.S. Government ... to ensure the
preservation of public order and to carry out governmental operations within its territorial
limits, or otherwise in accordance with applicable law, by force, if necessary.7
The emergency power, according to DOD directives, is available to protect federal property and
functions, and to authorize
prompt and vigorous Federal action, including use of military forces, to prevent loss of life
or wanton destruction of property and to restore governmental functioning and public order
when sudden and unexpected civil disturbances, disaster, or calamities seriously endanger
life and property and disrupt normal governmental functions to such an extent that duly
constituted local authorities are unable to control the situation.8
Ordinarily, the implementation of such operations must be authorized by executive order, but
DOD officials and military commanders may take emergency action without prior authorization
in cases where
sudden and unexpected civil disturbances (including civil disturbances incident to
earthquake, fire, flood, or other such calamity endangering life) occur, if duly constituted
local authorities are unable to control the situation and circumstances preclude obtaining
prior authorization by the President.9

5 See, e.g., Proclamation No. 6427, 57 Fed. Reg. 19,359 (May 1, 1992) (citing California governor’s notification and
request related to rioting in Los Angeles, and also determining that the “domestic violence and disorder are also
obstructing the execution of the laws of the United States”); Proclamation No. 6023, 54 Fed. Reg. 39,151 (September
20, 1989)(Virgin Islands).
6 See, e.g., Exec. Order No. 12804, 57 Fed. Reg. 19361 (May 1, 1992); Exec. Order No. 12690, 54 Fed. Reg. 39153
(September 20, 1989).
7 DOD Cooperation with Civilian Law Enforcement Officials, DOD Dir. 5525.5 (Encl. 4) § E4.1.2.3 (1989).
8 Id.
9 Military Assistance for Civil Disturbances, DOD Dir. 3025.12 § 4.2.2. (1994).
˜—›Žœœ’˜—Š•ȱŽœŽŠ›Œ‘ȱŽ›Ÿ’ŒŽȱ
řȱ

‘ŽȱœŽȱ˜ȱŽŽ›Š•ȱ›˜˜™œȱ˜›ȱ’œŠœŽ›ȱœœ’œŠ—ŒŽDZȱŽŠ•ȱ œœžŽœȱ
ȱ
‘ŽȱŠ˜›ȱŒȱ
The Robert T. Stafford Disaster Relief and Emergency Assistance Act (the Stafford Act, 42 U.S.C.
§§ 5121, et seq.) authorizes the President to make a wide range of federal aid available to states
that are stricken by a natural or man-made disaster.10 It provides statutory authority for employing
the U.S. armed forces for domestic disaster relief. Permitted operations include debris removal
and road clearance, search and rescue, emergency medical care and shelter, provision of food,
water, and other essential needs, dissemination of public information and assistance regarding
health and safety measures, and the provision of technical advice to state and local governments
on disaster management and control. The authority does not constitute an exception to the PCA.
In the event of a disaster that results in the wide-scale deterioration of civil law and order, the
authority to employ active duty troops to perform law enforcement functions must be found
elsewhere. The Stafford Act does not authorize the use of federal military forces to maintain law
and order. Federal forces would have no authority, for example, to act as traffic controllers or
provide security for facilities used in the relief efforts, unless such activities serve a valid military
purpose. Patrolling in civilian neighborhoods for the purpose of providing security from looting
and other activities, would not be permissible, although patrolling for humanitarian relief
missions, such as rescue operations and food delivery (which may have the incidental benefit of
deterring crime) would not violate the PCA. Military resources may be employed in the following
situations.
œœŽ—’Š•ȱœœ’œŠ—ŒŽȱǻŗŖȬŠ¢ȱž‘˜›’¢Ǽȱ
Upon the request of the governor, the President may task the Department of Defense to provide
any emergency work the President deems essential for the preservation of life and property in the
immediate aftermath of an incident that may ultimately qualify for assistance under a declaration.
Such assistance is available for up to ten days prior to a presidential declaration of an emergency
or a major disaster, 42 U.S.C. § 5170b(c). Emergency work can include the clearance and
removal of debris and wreckage and the restoration of essential public facilities and services, 42
U.S.C. § 5170(c)(6)(B). The provision is designed for instances where communications problems
impede the ability to meet the prerequisites for declaring an emergency or major disaster or the
ability to coordinate the work through FEMA.
–Ž›Ž—Œ¢ȱ
Unless the President determines that a disaster implicates preeminently federal interests, the
declaration of an emergency under the Stafford Act requires that the governor of the affected state
first make a determination that the situation is of such severity and magnitude that the state is
unable to respond effectively without federal assistance, which determination must include a
detailed definition of the type and amount of federal aid required, 42 U.S.C. § 5191. The
governor must also implement the state’s emergency response plan, for example, by activating the
state’s National Guard units under state control (in which case the PCA does not apply to them),
and provide information regarding the resources that have been committed.

10 For an overview of the Stafford Act, see CRS Report RL33053, Federal Stafford Act Disaster Assistance:
Presidential Declarations, Eligible Activities, and Funding
, by Keith Bea.
˜—›Žœœ’˜—Š•ȱŽœŽŠ›Œ‘ȱŽ›Ÿ’ŒŽȱ
Śȱ

‘ŽȱœŽȱ˜ȱŽŽ›Š•ȱ›˜˜™œȱ˜›ȱ’œŠœŽ›ȱœœ’œŠ—ŒŽDZȱŽŠ•ȱ œœžŽœȱ
ȱ
Š“˜›ȱ’œŠœŽ›ȱ
The prerequisites for a major disaster declaration are similar to those for an emergency, 42 U.S.C.
§ 5170. The governor must first execute the state’s emergency plan and make a determination that
state capabilities are insufficient to deal with the circumstances. However, the governor need not
specify which forms of assistance are needed. The governor must provide information regarding
the resources that have been committed and certify that the state will comply with cost sharing
provisions under the Stafford Act. There is no provision for the declaration of a major disaster
without the governor’s request. If the governor activates Guard units and keeps them under state
control, those units are not restricted by the PCA. If the state’s National Guard units are called
into federal service to respond to an emergency or a major disaster, their role is restricted to the
disaster relief operations authorized under the Stafford Act.
––Ž’ŠŽȱŽœ™˜—œŽȱž‘˜›’¢ȱ
DOD doctrine allows commanders to provide resources and assistance to civil authorities without
or prior to a declaration under the Stafford Act when a disaster overwhelms the capabilities of
local authorities and necessitates immediate action “to prevent human suffering, save lives, or
mitigate great property damage.”11 Immediate response actions can include the types of activities
authorized under the Stafford Act, including, at the request of civil authorities, rescue, evacuation,
and emergency medical treatment, restoration of essential public services, debris removal,
controlling contaminated areas, safeguarding and distributing food and essential supplies, and
supplying interim emergency communications.12 The immediate response authority may also
include law enforcement activities ordinarily prohibited by the PCA. The controlling directive
does not require a request from state or local officials, but states that
DoD Components shall not perform any function of civil government unless absolutely
necessary on a temporary basis under conditions of Immediate Response. Any commander
who is directed, or undertakes, to perform such functions shall facilitate the reestablishment
of civil responsibility at the earliest time possible.13
The immediate response authority is not provided for in any statute, but is said to have deep
historical roots.14 The 1906 San Francisco earthquake is a noted example. The commanding
general of the Pacific Division, on his own initiative, deployed troops to assist civil authorities to
stop looting, protect federal buildings, and to assist firefighters.15


11 U.S. Dep’t of Defense, Military Support to Civil Authorities, DOD Dir. 3025.1 § 4.5 (1993).
12 Id. § 4.5.1.
13 Id. § 4.4.10.
14 See Jim Winthorp, The Oklahoma City Bombing: Immediate Response Authority and Other Military Assistance to
Civil Authority (MAC)
, ARMY LAW. 3 (July, 1997).
15 Id. at 5.
˜—›Žœœ’˜—Š•ȱŽœŽŠ›Œ‘ȱŽ›Ÿ’ŒŽȱ
śȱ

‘ŽȱœŽȱ˜ȱŽŽ›Š•ȱ›˜˜™œȱ˜›ȱ’œŠœŽ›ȱœœ’œŠ—ŒŽDZȱŽŠ•ȱ œœžŽœȱ
ȱ
ž‘˜›ȱ˜—ŠŒȱ —˜›–Š’˜—ȱ

Jennifer K. Elsea
R. Chuck Mason
Legislative Attorney
Legislative Attorney
jelsea@crs.loc.gov, 7-5466
7-9294




˜—›Žœœ’˜—Š•ȱŽœŽŠ›Œ‘ȱŽ›Ÿ’ŒŽȱ
Ŝȱ