Case Explained: The Perils of Militarizing Law Enforcement – Legal Perspective

In August 2025, residents of Washington, D.C., awoke to a sight familiar in much of Latin America but rare in the United States: uniformed military troops patrolling city streets as part of a federally directed campaign against crime. Although violent crime in the country’s capital had fallen that January to its lowest point in over 30 years, on August 11 President Donald Trump signed an executive order that declared a “crime emergency” in the city, arguing that extraordinary measures were necessary to restore control. But the subsequent deployment of the National Guard—a military reserve force that can serve at both the state and federal levels in response to domestic crises or international conflict—signaled something beyond a wish to address a public safety concern. It represented a transformation in how the United States governs itself.

What unfolded in Washington was not an isolated episode. Over the course of Trump’s second term, his administration has sent or attempted to send units of the National Guard to major U.S. cities including Chicago, Los Angeles, Memphis, New Orleans, and Portland, framing each case as a response to crime, unrest, or threats to public order. Together, these cases mark the gradual erosion of the long-standing boundary between civilian policing and military force.

For American observers, such a shift may feel unprecedented. In Latin America, however, it is a well-worn path. Across the region, politicians have deployed the armed forces to fight crime, promising that their presence will produce swift improvements in public safety and restore order. These policies often begin as temporary responses to emergencies, but they rarely remain so. Instead, military involvement in domestic law enforcement becomes normalized, power concentrates in the executive, civilian institutions weaken, and civil liberties erode. Democratic institutions hollow out, slowly but surely.

The United States has long resisted this temptation. The separation of civilian policing from military force, deeply ingrained in both U.S. law and custom, has acted as a bulwark for American democracy. But the National Guard deployments, as sustained policing under federal command, challenge that separation. State governors can and have used National Guard troops to address local emergencies, but such operations are typically limited to assisting with natural disasters, riots, crowd control, and guarding buildings rather than participating in sustained law enforcement missions. And once the line between soldier and police officer is blurred, it is extraordinarily difficult to redraw. This is a reality Latin Americans know all too well, and one Americans may soon come to learn.

COP OUT

The political logic behind militarizing policing is straightforward. Crime generates fear, and fear creates a demand for visible, decisive action. Militaries—which are often among countries’ most trusted institutions—offer executives a powerful symbol of order, discipline, and resolve. Deploying soldiers to the streets signals strength, even when the underlying drivers of crime remain untouched.

For leaders confronting insecurity, militarizing policing is politically expedient precisely because it is legible, dramatic, and immediate. Regardless of its effectiveness, it tends to be popular because it offers a seemingly simple and decisive solution. It reassures communities by conveying a sense of retaking lost control. But no matter how popular it may be, militarization has harmful consequences for democratic institutions. Crime emergencies—often called “states of exception” in Latin America—give executives opportunities to expand their powers, degrade legislative and judicial oversight, and marginalize opponents. Civilian police forces stagnate or weaken while soldiers take on policing functions for which they are poorly suited. Government forces’ accountability declines and human rights abuses rise as soldiers ill equipped to protect civilians operate without constraints.

The Latin American experience shows how easily the militarization of internal security can become entrenched. Consider Mexico: in the 1990s, presidents increasingly used the military for internal security, dramatically expanding deployments after President Felipe Calderón declared a “war on drugs” in 2006. Two decades later, homicide rates in the country remain high, and abuses by security forces—including extrajudicial killings and enforced disappearances—have become widespread. Even left-of-center presidents who campaigned on demilitarization, such as Andrés Manuel López Obrador, who led the country from 2018 to 2024, have found it politically costly and institutionally challenging to reverse course. Once soldiers replaced civilian police in the fight against organized crime, the boundary between emergency and normal governance dissolved.

Once the line between soldier and police officer is blurred, it is extraordinarily difficult to redraw.

Brazil’s experience follows a similar pattern. Presidents have repeatedly sent troops into urban neighborhoods, including Rio de Janeiro’s favelas, to combat gangs and drug trafficking. Between 1992 and 2025, Brazilian executives have issued an average of about five decrees to “guarantee law and order” every year, and these military interventions have become normalized. Residents in certain areas have grown accustomed to periodic deployments involving patrols, searches, and arrests conducted by soldiers rather than police. The Brazilian armed forces’ excessive use of force in policing operations is well documented. But comprehensive statistics on abuse are hard to come by, and because soldiers’ actions during policing operations fall under military jurisdiction, victims cannot easily hold them to account for civil rights violations. Civilian nongovernmental organizations struggle even to scrutinize and document the extent of the abuse.

The military’s central role in Brazilian law enforcement is driven in part by the country’s legacy of military rule between 1964 and 1985. But the case of Ecuador illustrates how rapidly militarization can take hold even in a country without a long history of military rule. Beginning in the late 2010s and accelerating after a surge in organized criminal violence in 2021, successive Ecuadorian governments have increasingly turned to the armed forces for domestic policing. Presidents have declared repeated states of exception, authorizing soldiers to patrol streets, conduct searches without warrants, and assist police operations in urban centers and prisons. Although these measures were initially framed as temporary responses to extraordinary violence, they quickly became routine. Today, military deployments are no longer exceptional but an expected component of public safety policy. Although popular, such measures have done little to resolve underlying criminal dynamics. The country’s homicide rate, for example, increased more than fivefold between 2020 and 2025. Moreover, much-needed efforts to reform policing have taken a back seat as government funds are channeled toward military operations. 

El Salvador demonstrates the end point of this trajectory. In 2022, President Nayib Bukele implemented a 30-day state of exception that suspended citizens’ rights of free association and assembly, due process, and access to legal counsel. His administration also established the government’s right to detain people indefinitely before trial, conduct trials in absentia, and sentence minors as adults. Because of a steady reduction in violent crime since 2018—the year before Bukele took office—and the measures’ popularity, that state of exception has now been renewed 47 times by the legislature, which Bukele’s party controls, transforming into a permanent governing framework. The crackdown has sharply reduced reported homicides, but it has also radically transformed El Salvador’s regime, creating a system that perpetuates mass incarceration, indefinite detention, and the dismantling of judicial independence. Elections still occur, but meaningful constraints on executive power have largely vanished.

These and other cases in the region differ in context and outcome, but they share a common arc. Militarized public safety blurs the civilian-military divide, expands executive authority, and weakens institutions designed to constrain it. Even when its effectiveness is limited and its costs to liberal democracy are clear, military involvement in domestic policing becomes difficult to unwind once it is normalized.

A CURE WORSE THAN THE DISEASE?

This pattern raises an important question whose answer is often assumed rather than sought: Does militarized policing actually work? The popularity of military deployments, which enables their persistence, rests on the promise of restored order and reduced violence. Yet the empirical record is far less clear. In fact, existing research offers little support for the claim that military policing reduces crime over the long term. In the aftermath of Mexico’s militarization, its homicide rate more than tripled from nine to 29 homicides per 100,000 people between 2006 and 2019. Ecuador, for its part, went from being one of the safest to one of the most violent countries in the region; between 2020 and 2023, its homicide rate increased from seven to 44 homicides per 100,000 people. Although Brazil’s national homicide rate has gradually declined in recent years, the country’s Northeast has seen a surge in violent crime exacerbated, at least in part, by the government’s militarized response.

Studies have found that at best, troop deployments in Latin America might temporarily suppress violence but do not address the structural drivers of crime, from poverty and inequality to generalized corruption. Even worse, the measures can be counterproductive, possibly even increasing violence in the long term. Extensive evidence, including from research by political scientists Robert Blair and Michael Weintraub on Colombia and my own with Latin America scholar Jessica Zarkin on Mexico, suggests in fact that using soldiers in policing operations leads to more violence and human rights abuses than deploying civilian police does. Moreover, militarization often undermines civilian police forces by diverting their resources to the military, eroding public trust in them, and generating the perception that civilian institutions writ large are unable to solve society’s problems, all of which hinders accountability and much-needed reforms.

In the aftermath of Mexico’s militarization, its homicide rate more than tripled.

El Salvador’s drastic reduction of violent crime is often hailed as a successful case of militarization. After the country’s homicide rate peaked in 2015, the highest in the Western Hemisphere that year, El Salvador’s reported homicide rate is now the lowest in the hemisphere. Although the steep downward trend began before Bukele took office, this continued decline has earned Bukele sky-high popularity among Salvadorans—who had been desperate for solutions to insecurity—and, in 2024, a comfortable reelection to a second presidential term.

But Bukele’s path to his alleged success should be no example for a liberal democracy that prizes its citizens’ civil liberties and freedoms. The state of exception that paved the way for Bukele to get results on public safety has come through a suspended constitutional order in which anything goes. According to Amnesty International, thousands of arbitrary detentions and violations of due process have taken place since the state of exception began. This is hardly an example for addressing crime in a democratic system in which checks against government abuse are paramount to that system’s survival.

The United States is unlikely to be immune to these dynamics. Although the National Guard has some key domestic roles, including providing disaster relief, addressing health emergencies, and controlling riots, units are not trained primarily for ongoing civilian policing. The military’s rules of engagement, organizational culture, and legal frameworks differ fundamentally from those of police departments. These mismatches raise the risk of rights violations while offering little assurance that public safety will improve.

NO ORDER IN THE COURT

The deeper impact of these deployments is not on crime statistics but on the constitutional order. Militarized policing strengthens the executive at the expense of all other levels of government. State and local governments, which often know the needs of their communities the best, are sidelined from essential decision-making in favor of military commanders, who are often disconnected from the communities that their policies affect.

Emergency declarations also make it difficult for other branches of government to check executive power. Afraid of coming across as soft on crime, legislators become less likely to question emergency measures, and legislative oversight weakens. Although courts are typically less sensitive to public opinion, the declaration of crime emergencies often restricts or eliminates habeas corpus—which prevents unlawful detention—and due process, making judicial review harder, raising the bar for legal challenges, and increasing judicial deference to both the executive and the military.

Using soldiers in policing leads to more violence and human rights abuses.

Latin America’s experience with militarization makes this clear. In Mexico, civilian courts have shown considerable deference to the armed forces. And even though constitutional changes in 2014 established that soldiers could be tried in civilian courts for crimes against civilians, in practice, military authorities often limit or block the ability of civilian prosecutors to access evidence and collect testimony from witnesses. According to the nonprofit organization Washington Office on Latin America, 97 percent of abuses by the armed forces that are investigated by the Mexican attorney general’s office go unpunished. Civilian police departments receive little funding, and the military has become increasingly involved in public life, including in building and managing infrastructure projects.

In Ecuador, organized crime groups are now considered “terrorist and belligerent non-state actors” following a January 2024 declaration of internal armed conflict, which limited citizens’ freedom of assembly and transit and expanded the military’s ability to conduct home searches without a warrant. President Daniel Noboa has consistently renewed states of exception, turning them into the norm. In El Salvador, Bukele’s party replaced every judge on the country’s constitutional court under the guise of protecting the president’s crime-fighting agenda. In Brazil, surveys during Jair Bolsonaro’s presidency, which lasted from 2018 to 2024, suggested that nearly half the population would have supported the military staging a coup to take power—a direct consequence of the military’s increasing involvement in public affairs and the erosion of faith in the ability of civilians to resolve society’s problems.

NO TURNING BACK

American democracy has long benefited from a clear institutional separation between civilian and military roles. This division has been a central tenet of U.S. governance since the founding of the republic, shared even by those with opposing political views. Alexander Hamilton, a Federalist, warned that military establishments undermine republican government, infringe on civil liberties, and lead to despotism. Brutus, an anonymous but widely read Antifederalist, expressed graver concerns that manufactured crises would serve as a pretext for attempts by the military to override civilians’ liberty. In 1807, Congress passed the Insurrection Act to clarify confusing prior legal frameworks that allowed the president to call on state militias in cases of violent revolts such as the 1794 Whiskey Rebellion. But in passing the act, the legislature was careful to limit the executive branch’s ability to deploy federal troops domestically: it can do so only when federal law cannot be enforced through regular channels or when state authorities cannot or will not protect citizens’ constitutional rights. Then, in 1878, Congress adopted the Posse Comitatus Act as a form of late institutional repair, an effort to address the founders’ early concerns about military abuse; it sought to prevent the military deployments that took place in the South during Reconstruction. The act expressly forbids the use of federal troops to execute domestic laws except under specific circumstances, such as the need to address an insurrection.

These normative and legal frameworks explain why Washington had historically gone to extreme lengths to avoid militarized policing. The Insurrection Act, for its part, has been invoked only in extraordinary circumstances, such as when President Dwight Eisenhower deployed federal troops to Arkansas in 1957 to enforce school desegregation. In the United States, a clear civil-military separation has always limited the president’s ability to govern by force instead of by law. Its erosion, even a partial or incremental one, risks reshaping the balance of power in ways that would outlast any single administration. It also risks undermining the public’s trust in civilian governments.

Militarized policing strengthens the executive at the expense of all other levels of government.

The United States still has options. Governors and mayors are engaging in legal fights to assert state and local control over public safety. The judiciary has served as a check against some deployments: in December, the Supreme Court allowed lower court rulings against the federalization of the National Guard in Chicago to stand. But these safeguards depend on political will and a generalized understanding of the negative consequences that come with blurring the line between soldiers and police. Although some may see the militarization of policing as a necessary evil to advance the agenda of a government they support, the use of these measures tends to outlive the leaders who adopt them, becoming available to future governments with very different visions.

Once militarized policing becomes normalized, efforts to demilitarize face broad resistance: from voters accustomed to displays of force, from security institutions hesitant to give up their expanded power and resources, and from leaders reluctant to relinquish their broadened authority. Every time troops are deployed to American communities for public safety reasons, even if temporarily and even if they seem to be contributing to reductions in crime, this central pillar of our democracy erodes. If Americans come to accept military patrols as a routine response to crime, the distinction that once protected U.S. democracy may fade quietly—without a dramatic rupture, but with lasting consequences.

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