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The Posse Comitatus Act: Enduring Policy Against Direct Military Law Enforcement

By: Robert Klein

October 26, 2020

I. Introduction

Posse comitatus (“the power of the country”) refers to a group of citizens summoned by law enforcement to assist in peacekeeping or rescue operations.1Posse comitatus, Black’s Law Dictionary (11th ed. 2019). It is effectively a civilian draft power for local sheriffs to conscript temporary personnel to aid in an emergency. The sheriff’s authority to call upon the citizenry was traditional at common law.

Enacted in 1878 and updated in 1956 to include the Air Force, the Posse Comitatus Act makes it a federal crime to use the military for posse comitatus or domestic law enforcement:

Whoever, except in cases and under circumstances expressly authorized by the Constitution or Act of Congress, willfully uses any part of the Army or the Air 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.218 U.S.C. § 1385. Under the authority of 10 U.S.C. § 275, Department of Defense regulations apply the Posse Comitatus Act to the Navy and the Marine Corps. 32 C.F.R. §§ 182.4, 182.6.

Even though there is vigorous debate over interpreting the Act, no one has ever been prosecuted for a violation.3Gary Felicetti & John Luce, The Posse Comitatus Act: Setting the Record Straight on 124 Years of Mischief and Misunderstanding Before Any More Damage Is Done, 175 Mil. L. Rev. 86, 163 (2003) (citing H.R. Rep. No. 97-71, pt. I (1981) (“According to a spokesman for the Department of Justice, no one has been charged or prosecuted under the Posse Comitatus Act since its enactment. Testimony of Edward S.G. Dennis Jr. on behalf of the Department of Justice”) (internal citation omitted)). Yet it remains an enduring limitation on the military in domestic life. Recent increases in military support of local policing call for a reexamination of the boundary between civilian policing and military operations. While the military’s increasing support for law enforcement operations could threaten the separation between the military and local police, the military has yet to clearly cross the boundaries of the Posse Comitatus Act.

II. History of the Posse Comitatus Act

To make sense of American attitudes about military law enforcement and the impetus behind the Posse Comitatus Act, it is necessary to understand the ancient roots of resistance to expansions of posse comitatus. The concept of posse comitatus derives from the Roman practice of civilians accompanying proconsuls (provincial governors) as they traveled to their places of duty.4Nathan Canestaro, Homeland Defense: Another Nail in the Coffin for Posse Comitatus, 12 Wash. U. J.L. & Pol’y 99, 102 (2003) (citing Major H.W.C. Furman, Restrictions Upon Use of the Army Imposed By the Posse Comitatus Act, 7 Mil. L. Rev. 85, 87 (1960)). In the Anglo-American legal tradition, posse comitatus dates back to the thirteenth century, when antimilitary sentiment led to reliance on able-bodied civilian men over the age of fifteen to assist law enforcement.5Id. (citing William O. Douglas, The Right of the People 112 (1972)). In 1628, Parliament outlawed the quartering of soldiers in civilian homes, as well as martial law military commissions for routine law enforcement and judicial punishment.6Cong. Research Serv., The Posse Comitatus Act and Related Matters, at 2 (updated Nov. 6, 2018), https://fas.org/sgp/crs/natsec/R42659.pdf. Parliament perceived these practices, ordered in peacetime by King Charles I, as violations of due process protections guaranteed by the Magna Carta, which prohibited deprivation of one’s liberty or property “except by the lawful judgment of his peers or by the law of the land.”7Id. (citing Magna Carta, ch. 39 (1225), reprinted in William F. Swindler, Magna Carta: Legend and Legacy 315-16 (1965)). By granting the King’s agents summary legal authority, military policing visited monarchical power on local affairs and contravened the guarantee of due process.

Continued use of martial law contributed to the English Civil War in 1642, and the bloody Cromwell dictatorship between 1653 to 1658 sparked more resistance to domestic use of the military in peacetime.8Canestaro, supra note 4, at 103 (citing William O. Douglas, The Right of the People 113 (1972)). Thus, Parliament’s 1689 Bill of Rights declared “that the raising or keeping [of] a standing army within the Kingdome in time[s] of peace, unless it be with the consent of Parliament, is against law.”9Id. (citing William O. Douglas, The Right of the People 112 (1972)). The Riot Act of 1714 restricted sheriffs to calling upon the posse comitatus only after ordering an unruly crowd to disperse, but “strictly forbade employing the army in this same role, as the military force was solely reserved for suppressing open rebellion.”10Id. (citing David E. Engdahl, Foundations for Military Intervention in the United States, 7 U. Puget Sound L. Rev. 1 (1983) (internal citation omitted)). The long history of law and custom against military presence in civilian life engendered civilian expectations of due process and freedom from arbitrary judgments.

This traditional mistrust of the military crossed the Atlantic to American shores as the British colonized North America, and it was a principal grievance motivating colonial unrest and the American Revolution.11Id. at 105. Tensions boiled over at the Boston Massacre, when British troops killed five colonists in a crowd who had taunted the British soldiers with rocks and snowballs; the use of professional troops without parliamentary authorization infuriated the colonists.12Canestaro, supra note 4, at 106-07. Thus, the Declaration of Independence complained that the British king “had ‘kept among us, in times of peace, Standing Armies without the consent of our legislatures,’ had ‘[rendered] the Military independent of and superior to the civil power,’ and had ‘quarter[ed] large bodies of armed troops among us…protecting them…from punishment for any murders which they should commit…’”13Cong. Research Serv., supra note 6, at 4. The Bill of Rights accordingly limits quartering troops in private homes and guarantees the right to keep and bear arms as part of “a well regulated militia, being necessary to the security of a free State.”14U.S. Const. amends. II & III. The “militia” refers to state-level forces that would ensure public safety and provide a check on a national military—a check that James Madison argued would prevent tyranny.15The Federalist No. 46 (James Madison). These amendments vindicated the colonists’ anger at the colonial government’s overreach, dispersing armed power to the states. Nevertheless, the Constitution grants Congress the power “to provide for calling forth the Militia to execute the Laws of the Union, suppress Insurrections and repel Invasions,”16U.S. Const. art. I, § 8, cl. 15. entrusting Congress with discretion to employ the military in domestic law enforcement. In contrast, the President wields the Commander in Chief power over the armed forces but cannot use the troops for law enforcement except pursuant to a Posse Comitatus Act exception or other express authorization by Congress.17U.S. Const. art. II, § 2, cl. 1.

This was not always the case. In the early American republic, Congress passed authorizing statutes allowing the President to call forth the military to put down rebellions against taxes and duties, deploy troops upon request of a state, fight lawlessness in the expanding West, and enforce civil rights in the postbellum South—to name just a few examples.18Cong. Research Serv., supra note 6, at 7-17. Notably, the Judiciary Act of 1789 authorized the President to deploy federal marshals to “effectuate [the federal government’s] constitutional powers and provide a means to enforce the process of federal courts.”19Id. at 5-6. Nineteenth-century presidents viewed the Judiciary Act as including military forces within the posse comitatus, historically not available to sheriffs, even though the Act did not expressly include the military.20Id. at 6. See also Major H. W. C. Furman, Restrictions Upon Use of the Army Imposed by the Posse Comitatus Act, 7 Mil. L. Rev. 85, 87 (1960) (citing the opinion of President Pierce’s Attorney General, Caleb Cushing). An 1854 opinion by President Pierce’s Attorney General, Caleb Cushing, formalized this policy.21Felicetti & Luce, supra note 3, at 99 (citing 6 Op. Att’y Gen. 466, 473 (1854)). The Cushing Doctrine facilitated enforcement of the Fugitive Slave Act, which entitled the owners of fugitive slaves to an arrest warrant by federal marshals, who in turn could enlist the citizenry and troops as posse comitatus.22See Cong. Research Serv., supra note 6, at 18. This was “undoubtedly popular” with Southern slaveholders, until federal troops became symbols of Northern interference following the Civil War and abolition of slavery.23Felicetti & Luce, supra note 3, at 99-100.

Unsurprisingly, white Southern attitudes towards federal military law enforcement soured in the immediate postbellum period. In the early years of Reconstruction, Black and white federal troops occupied the former Confederacy, and the initiative of Black troops associated the Army with “the rise of black political power and organization,” enraging Southern whites who saw the Army as a symbol of the South’s destruction.24Id. at 100-02. This prompted southern state legislatures to pass laws discriminating against free Black citizens, and state governments effectively condoned widespread racial terrorism.25Id. at 102-05. As Reconstruction faded, there was only sporadic federal military law enforcement against racist laws and violence, paving the way for nearly another century of de jure discrimination.26Id. at 106-09.

Federal military supervision of the 1876 election was the final straw. President Grant dispatched troops to supervise polling places in Southern states to prevent intimidation and violence against Black voters, as well as fraud by would-be ballot stuffers.27Id. at 108-09. When neither presidential candidate secured a majority of the electoral college, the parties made a deal to certify Republican Rutherford B. Hayes as the victor in exchange for the withdrawal of most federal troops from the South, ending Reconstruction without securing the rights of free Black Americans.28Id. at 109. Hayes defeated Samuel Tilden, former professor at NYU Law. A plaque honoring his memory sits at the top of the spiral staircase in Vanderbilt Hall.

In 1877, members of the Democratic-controlled House railed against the use of troops to keep the peace at the polls in 1876.29Id. at 110. Congressman John Atkins, Democrat of Tennessee and former member of the Confederate Congress, submitted an appropriations rider effectuating a reduction of Army forces and restrictions on their use in domestic affairs.30Id. Atkins argued against maintaining a standing army,315 Cong. Rec. 2112 (1877) (remarks of Rep. Atkins). characterizing it as an extension of the tyranny of the European powers. He believed that standing armies waste public resources, embolden a landed aristocracy, and generate needless wars.32Id. Couched in the language of freedom and human rights, Atkins’s arguments concealed the true motivation for weakening the federal military: allowing Southern states the freedom to enforce racial segregation and permit anti-Black terrorism with impunity, contravening the Reconstruction amendments. Military lawyers Gary Felicetti and John Luce remarked in their article on posse comitatus that Atkins’s bill “might be more accurately described as the Ku Klux Klan Protection Act.”33Felicetti & Luce, supra note 3, at 111 n.115. The Senate stripped Atkins’s amendment from the appropriations bill, and the issue of the military as posse comitatus laid dormant until the next session of Congress.  

In 1878, Congressman William Kimmel, Democrat of Maryland, sponsored the language that became the core of the Posse Comitatus Act. Kimmel portrayed President Hayes as an imperious monarch, railed against the dangers of a standing army, and painted the ordinary soldier as a bloodthirsty and brutal threat to civil peace.34Id. at 111 (citing 7 Cong. Rec. at 3584 (1874) (“ He lives by blood! His is a business apart from the people …. [H]is habits unfit him for the relations of civil life …. He sacks, desecrates, indulges when and where he dares. He serves, obeys, destroys, kills, suffers [,] and dies for pay. He is a mercenary whom sloth, luxury[,] and cowardice hires to protect its ease, enjoyment, and life.”)). Felicetti and Luce observe that the context of the debate and overt references to Reconstruction “tyrants” and racial harmony make it “difficult to dispute the bill’s reflection of lingering Reconstruction bitterness or the sponsor’s agenda.”35Felicetti & Luce, supra note 3, at 112. After a few revisions in the House and Senate, including the exclusion of the Navy from the bill, the Posse Comitatus Act became law on June 18, 1878.

III. Expanding Mission: The Military’s Supporting Role for Civil Law Enforcement

The Posse Comitatus Act generated little controversy for more than a century, but the rise of transnational law enforcement concerns convinced Congress to begin pruning it back in the late twentieth century. Notably, in the 1980s, Congress expanded the military’s law enforcement role as part of the War on Drugs, allowing military support of counterdrug operations through aerial surveillance, personnel transport, and loans of equipment and personnel.36Sean J. Kealy, Reexamining the Posse Comitatus Act: Toward A Right to Civil Law Enforcement, 21 Yale L. & Pol’y Rev. 383, 409; 412 (2003) (“The [1981 Military Cooperation with Law Enforcement Officials] Act clarified and ‘mildly’ expanded the powers of the military to cooperate with law enforcement by providing equipment, research facilities, and information; by training and advising police on the use of loaned equipment; and by assisting law enforcement personnel in keeping drugs from entering the country”) (internal citation omitted). These actions stop short of the type of direct law enforcement involving military-citizen encounters that the Posse Comitatus Act proscribes.

It is reasonable to question whether the distinctions separating the military’s support role from direct law enforcement are strong enough to prevent spillover. Colonel Charles Dunlap observes, “[M]ore than anything else the drug problem has pushed the armed forces into institutionalized participation in law enforcement matters.”37Charles J. Dunlap, Jr., The Police-ization of the Military, 27 J. Pol. & Mil. Soc. 217, 220 (1999). Indeed, the statutory authorities underlying counterdrug support confer a high degree of discretion to the military to contribute to domestic law enforcement. The Secretary of Defense has discretionary authority to share with federal, state, or local law enforcement “any information collected during the normal course of military training or operations that may be relevant” to violations within those agencies’ jurisdiction.3810 U.S.C. § 271(a) (2016). The same statute provides that the needs of civil law enforcement “shall, to the maximum extent practicable, be taken into account in the planning and execution of military training or operations,” and that the Department of Defense shall “promptly” furnish intelligence information relevant to law enforcement.39Id. §§ 271(b), (c). The Secretary of Defense also may make military equipment and facilities available to law enforcement officials for law enforcement purposes.40Id. § 272. Thus, a broad scope of military resources and military-collected information may factor into law enforcement operations. This effectively maintains the Posse Comitatus Act’s legal boundaries by redirecting federal military resources towards civilian law enforcement without the use of military troops as agents. But as a practical matter, the military’s role in these operations undoubtedly expands and routinizes its presence in domestic law enforcement.

While the Posse Comitatus Act prohibits direct law enforcement by the military, the military can play a supporting role to local police operations. After the September 11 terrorist attacks, the military greatly expanded North American operations in support of local law enforcement. In October 2002, the Department of Defense activated the U.S. Northern Command, “the first time a single military commander has been charged with protecting the U.S. homeland since the days of George Washington.”41USNORTHCOM Command Historian, A Short History of U.S. Northern Command (Sept. 26, 2019), https://www.northcom.mil/Newsroom/Fact-Sheets/Article-View/Article/1972077/a-short-history-of-us-northern-command/. The command has provided defense support to civil authorities upon request, usually in response to natural disasters.42Id. The chain of command runs from the President to the Secretary of Defense to the commander of USNORTHCOM unless the President otherwise orders, so the establishment of USNORTHCOM has the potential to expand the President’s influence over domestic law enforcement.4310 U.S.C. § 162(b) (2019). Military leaders had long hesitated to the proposal for this command because the military’s approach to operations is much different than that of law enforcement, reflecting incompatible forms of training: “Where the military sees enemies of the United States, a police agency – properly oriented – sees citizens suspected of crimes but innocent until proven guilty in a court of law. These are two different views of the world.”44Dunlap, supra note 37, at 223. As USNORTHCOM’s operations have developed, these concerns have not yet proven true, although merely having such a structure in place may create a risk of hasty expansion during the next emergency.

During its first month of operation, USNORTHCOM provided aerial surveillance equipment to the FBI in the hunt for the D.C. sniper, who killed fourteen people and critically injured three others.45Lisa L. Turner, Jeanne Meyer & Harvey Rishikof, Understanding the Role of Northern Command in Defense of the Homeland: The Emerging Legal Framework–Authorities and Challenges, in Homeland Security: Legal and Policy Issues 43, 54-55 (Joe D. Whitley & Lynne K. Zusman, eds., 2009). While military personnel flew the plane and operated the surveillance equipment, “the FBI directed the surveillance, flight plan, and follow-on law enforcement.”46Id. Thus, as in the counterdrug context, “the military was simply operating equipment rather than engaging in or actively supporting law enforcement activities.”47Id. at 55. The distinction between training, equipment loans, and operational support – as opposed to searches, seizures, and arrests – is the borderline drawn by the Posse Comitatus Act. Accordingly, the military has strict limitations on the use of force in these domestic support missions: “If any level of force is required, normally for self-defense, the lowest level of force is usually required, and only to the point of allowing civilian law enforcement to engage and address the threat.”48Id. Further, “[u]nlike other geographic commands, few forces are permanently assigned to USNORTHCOM . . . [r]ecognizing the sensitivity to a standing military force in the homeland.”49Id. at 46. Thus, while the President’s power to direct USNORTHCOM could lead to abuses, the command by structural design is careful to avoid treading too close to direct law enforcement, instead facilitating a supporting role short of direct interaction with civilians.

IV. Application to the COVID-19 Pandemic

As the COVID-19 pandemic has upended life in the United States and across the world, there has been renewed focus on presidential emergency authorities applicable to such an extraordinary situation. In March 2020, the White House activated the National Guards of California, New York, and Washington under Title 32, which federally funds operations while leaving control to governors.50Lindsay Cohn & Jim Golby, The U.S. Military’s Role in the Coronavirus Response is Likely to Grow, Wash. Post (Mar. 30, 2020), https://www.washingtonpost.com/politics/2020/03/30/us-militarys-role-coronavirus-response-is-likely-grow/. This generated conspiracy theories that the military would enforce widespread quarantines and curfews, including email hoaxes that the military was preparing for martial law.51Id. The Department of Defense responded with a “Rumor Control” website discussing “Myth” and “Fact” on its COVID-19 operations.52U.S. Dep’t of Defense, Coronavirus: Rumor Control, https://www.defense.gov/Explore/Spotlight/Coronavirus/Rumor-Control/ (last updated June 30, 2020). Given the infrequency of this kind of national emergency, it is understandable that there would be misinformation and public confusion, but the Posse Comitatus Act makes clear that the military cannot engage in law enforcement outside a constitutional or statutory exception. The interaction of the Posse Comitatus Act with emergency presidential authorities generally mirrors the military’s ability to support law enforcement in the counterdrug context. In other words, the President cannot use the military for direct law enforcement, barring a Posse Comitatus Act exception. 

Federal quarantine authorities, exercised on a mass scale, could expand the role of the military in domestic life. While state authority under the general police power is the “primary basis” for declaring and enforcing quarantines, the federal government also derives quarantine and isolation power from the Commerce Clause of the Constitution.53Jesse T. Greene, Federal Enforcement of Mass Involuntary Quarantines: Toward A Specialized Standing Rules for the Use of Force, 6 Harv. Nat’l Sec. J. 58, 68–69 (2015). Under the Public Health Service Act of 1944, Congress granted the Executive Branch authorities for quarantining individuals whose communicable diseases may cause infections across state lines. Unlike the states, the federal government can only designate individuals for quarantine and cannot order regional or national policies. The Secretary of Health and Human Services may authorize the Surgeon General to promulgate and enforce regulations that, in the Surgeon General’s judgment, “are necessary to prevent the introduction, transmission, or spread of communicable diseases from foreign countries into the States or possessions, or from one State or possession into any other State or possession.”5442 U.S.C. § 264(a). Regulations may also be developed that, on executive order of the President in consultation with the Secretary and the Surgeon General, permit the federal government to apprehend, examine, and detain individuals who are “reasonably believed” to be infected with a communicable disease and may spread it among states.5542 U.S.C. §§ 264(b)-(d).

The regulations promulgated pursuant to these provisions give the Director of the Centers for Disease Control and Prevention (or another representative authorized by the HHS Secretary) power to issue and oversee federal quarantine orders of individuals.5642 C.F.R. § 70 (2019). The Director may order medical examinations of a quarantined individual, a power that touches upon the fundamental constitutional right of bodily autonomy, reflecting a substantial grant of executive power.57Id. Congress provided that an individual who violates a federal quarantine order may be fined up to $1,000 and imprisoned for up to one year.5842 U.S.C. § 271(a). In the COVID-19 context, these quarantine authorities are powerful because the federal government could easily determine that an individual with a communicable disease will move between states or infect other people moving between states, permitting invocation of the power. However, barring a collapse of civil order in an affected state, the military is unlikely to conduct apprehensions and detentions because other federal law enforcement is available for that purpose, avoiding Posse Comitatus Act problems. But the military may provide civil support functions, like treating patients and conducting medical examinations, so it could be a component of federal quarantine policies without executing the law.59Cong. Research Serv., The Role of the Department of Defense During A Flu Pandemic 7 (2009), https://fas.org/sgp/crs/natsec/R40619.pdf. In the current pandemic, the military has extensively served these functions outside of the federal quarantine context, deploying over 61,000 personnel in March and April to build care facilities, conduct medical research, and aid hospitals in treating patients.60Bradley Bowman & Maj. Liane Zivitski, America’s Military Goes to War Against the Coronavirus, Mil. Times (Apr. 26, 2020), https://www.militarytimes.com/opinion/commentary/2020/04/26/americas-military-goes-to-war-against-the-coronavirus/.

The military’s role in quarantine enforcement is likely to be more active in supporting state enforcement of public health orders. As discussed earlier, the Department of Defense has broad authority to provide support to civil law enforcement, so the military may be a major factor in executing a state’s stay-at-home policy. As in the counterdrug context, military support of law enforcement in a pandemic could approach execution of the law. Defense support may include “providing base and installation support to federal, state, local, and tribal agencies; controlling movement into and out of areas, or across borders, with affected populations; supporting law enforcement; supporting quarantine enforcement.”61Cong. Research Serv., supra note 59, at 7. Echoing the arguments of drug crime defendants, military lawyer Jesse T. Greene notes that “[t]he line between support to an activity and execution of the activity is not always clear.”62Greene, supra note 53, at 70 (emphasis in original). Because it is difficult to show a violation of the Posse Comitatus Act sufficient to suppress evidence at a criminal trial,63See United States v. Hartley, 796 F.2d 112, 114 (5th Cir. 1986) (denying a motion to suppress where the military’s did not have a “pervasive” role in a counterdrug operation and did not directly interdict the suspects); Hayes v. Hawes, 921 F.2d 100, 104 (7th Cir. 1990) (denying a motion to suppress where there was not “pervasive” military activity or “widespread and repeated” violations). the blurred lunes between military support and direct law enforcement are unlikely to generate a case leading to judicial enforcement of the Act relating to the military’s COVID-19 operations. As noted earlier, the Act does not apply to National Guard forces under the authority of their respective states, so governors could augment regular law enforcement with personnel that appear as regular military to civilians.

General disaster relief authorities under federal law provide a significant role for military support. The President has authority under the Stafford Act to deploy the military for disaster relief purposes, limited by the Posse Comitatus Act’s ban on using the military for domestic law enforcement.64Brennan Center for Justice, A Guide to Emergency Powers and their Use 1-2, https://www.brennancenter.org/sites/default/files/2019-10/2019_10_15_EmergencyPowersFULL.pdf (last updated Sept. 4, 2019). Upon a request by the governor of the affected state, the Stafford Act authorizes the President to declare a state of emergency where federal assistance is necessary because the “severity and magnitude” of the crisis overwhelm state and local capabilities.6542 U.S.C. § 5191(a) (2013). Analogous provisions permit emergency declarations upon the request of the Chief Executive of an affected Indian tribal government.66Id. § 5191(c). The emergency declaration allows the President to mobilize the resources and personnel of federal agencies to execute numerous relief functions, including debris removal, distribution of supplies, and aiding evacuations.67Id. § 5192. While governors of many states have requested federal assistance, a March 2020 op-ed by New York Governor Andrew Cuomo illustrates how states can seek military aid to increase COVID-19 testing and hospital infrastructure.68Andrew M. Cuomo, Andrew Cuomo to President Trump: Mobilize the Military to Help Fight Coronavirus, N.Y. Times (Mar. 15, 2020), https://www.nytimes.com/2020/03/15/opinion/andrew-cuomo-coronavirus-trump.html.

On March 13, 2020, Donald Trump declared a nationwide emergency69Letter from President Donald J. Trump on Emergency Determination Under the Stafford Act (Mar. 13, 2020), https://www.whitehouse.gov/briefings-statements/letter-president-donald-j-trump-emergency-determination-stafford-act/. under a rarely invoked provision that permits the President to unilaterally determine than an emergency “involves a subject area for which . . . the United States exercises exclusive or preeminent responsibility and authority.”7042 U.S.C. § 5191(b) (2013). This was a fairly extraordinary act because, as of 2014, “there have been only three unilateral emergency declarations in the history of the Stafford Act.”71Michael Bahar, The Presidential Intervention Principle: The Domestic Use of the Military and the Power of the Several States, 5 Harv. Nat’l Sec. J. 537, 628 (2014). Bill Clinton invoked this power in the wake of the Oklahoma City bombing of the Alfred P. Murrah Federal Building, and George W. Bush issued two such declarations, respectively for the Space Shuttle Columbia Disaster and to ensure security at Barack Obama’s inauguration.72Id. Like COVID-19, these examples involve events with a strong federal interest and scope of responsibility. The White House’s COVID-19 announcement stated, “It is the preeminent responsibility of the Federal Government to take action to stem a nationwide pandemic that has its origins abroad, which implicates its authority to regulate matters related to interstate matters and foreign commerce and to conduct the foreign relations of the United States.”73Letter from President Donald J. Trump on Emergency Determination Under the Stafford Act, supra note 67. This assertion of emergency power, declared without consent of the affected states, envisions a strong federal role in combatting the coronavirus pandemic. It also evinces a belief that COVID-19 requires a wholly national response, whereas state by state emergency requests are more appropriate for local natural disasters.

Trump later announced the deployment of 1,000 federal troops to New York City to aid understaffed hospitals and serve in the Javits Center convention hall, which was temporarily converted to hospital space.74Emma Newburger, Trump Says 1,000 Military Personnel Deploying to New York City, Warns Coming Week Toughest Yet in Coronavirus Fight, CNBC (Apr. 4, 2020),  https://www.cnbc.com/2020/04/04/trump-says-1000-military-personnel-are-deploying-to-new-york-city-to-fight-coronavirus.html. Trump said, “They’re going into war . . . . They’re going into a battle they’ve never really trained for.”75Id. Despite the perhaps non-literal sentiment of this statement, the legal basis for the deployment permits aiding states and localities–not fighting a war or battle–which must be declared by Congress.76U.S. Const. art. I, § 8, cl. 11. In a recent update, the Department of Defense took care to distinguish the armed services’ function as a “warfighting force” from its COVID-19 support activities, such as deploying field hospitals, treating patients, and distributing medical-grade masks from the national stockpile.77Jim Garamone, DOD Continually Examines, Modifies COVID-19 Response, DoD News (Apr. 6, 2020), https://www.northcom.mil/Newsroom/Article/2139862/dod-continually-examines-modifies-covid-19-response/. These functions cleanly fit within support activities, as distinct from law enforcement prohibited by the Posse Comitatus Act.

Recent armed protests against state stay-at-home orders and business closures could authorize a military response should the demonstrations turn violent. Some of these protesters don combat-style gear and weaponry, and there have been confrontations between the protesters and law enforcement.78See, e.g., Manny Fernandez & David Montgomery, Businesses Chafing Under Covid-19 Lockdowns Turn to Armed Defiance, N.Y. Times (May 13, 2020), https://www.nytimes.com/2020/05/13/us/coronavirus-businesses-lockdown-guns.html. Under the Insurrection Act, Congress provided an exception to the Posse Comitatus Act that allows the President to order military law enforcement in cases of rebellion that makes ordinary judicial enforcement of federal law impracticable.7910 U.S.C. § 252. The President may also issue such an order to repel insurrection against a state government at the state’s request.80Id. § 251. In either situation, the President must first issue a proclamation to disperse peaceably, leaving a military response as a last resort.81Id. § 254. The Insurrection Act was last activated by George H.W. Bush, who, at the request of the Governor of California, issued a proclamation to disperse during the 1992 Los Angeles riots, and authorized the military to suppress violence.82Proclamation No. 6427, 57 Fed. Reg. 19359 (May 1, 1992); Exec. Order. No. 12804, 57 Fed. Reg. 19361 (May 1, 1992). If the COVID-19 armed protests spin out of control into riots challenging the abilities of local police, an Insurrection Act exception to the Posse Comitatus Act may be available.

V. Conclusion

While military support for civil law enforcement has increased since the 1980s counterdrug laws, the Posse Comitatus Act remains an enduring and meaningful restriction on military execution of the laws. The ancient Anglo-American resistance to military involvement in daily life has proved durable. Yet increased military support contributions to law enforcement complicate the traditional separation between police and the military. The COVID-19 pandemic appears unlikely to upend the current balance; so far, the military has not broached the boundary of the Posse Comitatus Act. Over the coming months and years, the potential for civil unrest and extended emergency response will test the longstanding separation of the military from domestic life. Congress may wish to study how developments in the 21st century impact this balance and consider legislation that would ensure a wider separation between routine policing and military operations.


Robert Klein, J.D. Class of 2021, N.Y.U. School of Law

Suggested Citation: Robert Klein, The Posse Comitatus Act: Enduring Policy Against Direct Military Law Enforcement, N.Y.U. J. Legis. & Pub. Pol’y Quorum (2020).