Center for American Progress

Domestic Deployment of the Military: The Past, Present, and Potential Future
Report

Domestic Deployment of the Military: The Past, Present, and Potential Future

Since the founding of the United States, domestic deployment of the military has been a move of last resort; that may be about to change.

In this article
Texas National Guard soldiers install border fencing near the Rio Grande.
Texas National Guard soldiers install border fencing near the Rio Grande on April 2, 2024, in El Paso, Texas. (Getty/Brandon Bell)

Introduction and summary

In 2022, then-former President Donald Trump stated that “the next President should use every power at his disposal to restore order — and, if necessary, that includes sending in the National Guard or the troops” to conduct law enforcement activities on U.S. soil. In 2023, he went even further, implying that he would deploy the military to major U.S. cities to combat crime: “The next time, I’m not waiting. … We don’t have to wait any longer.” Then, less than a month before the 2024 election, Trump proposed deploying the military to combat “the enemy from within”—opponents on the left who he defines as “lunatics.”

With President Trump now in office, it is worth taking a moment to discuss just how his administration could use the U.S. military to enforce his policy agenda. This report begins with a historical review of domestic deployment, before outlining where the nation stands today. It concludes with a brief discussion of the ways in which the public can hold the military accountable for any unconstitutional or illegal conduct.

A historical review of domestic deployment

On October 1, 1768, the British government deployed more than 2,000 troops to the colony of Massachusetts. Parliament had recently enacted a series of incredibly unpopular tax laws, and the colonists were not happy with their British rulers. Cries of “no taxation without representation” were commonplace, as were hushed demands for independence. This increased military presence led to frequent confrontations between colonists and soldiers, several of which ended in violence. The tension hit a fever pitch on the night of March 5, 1770, when, in response to colonists throwing rocks and snowballs at a British officer, Captain Thomas Preston and his men opened fire on the civilian crowd, killing five colonists and injuring many more. This tragedy is known today as the Boston Massacre.

The massacre etched in the founders’ minds the dangers of domestic deployment of the military. The presence of soldiers in a civilian environment escalated a snowball fight into a gun battle—a lesson the founders did not forget when drafting the Constitution. Article I, Section 8 and Article II, Section 2 split military authority between the president and Congress to prevent either branch from using the armed forces to carry out their policy agenda, as the British did in Boston. The constitutional compromise is that the president is the commander in chief but Congress declares war and funds the military. Furthermore, the Bill of Rights established key due process protections for American citizens against government incursion—including against the military. The fact that the Third Amendment is singularly focused on prohibiting soldiers from quartering in civilian homes without consent proves that military overreach weighed heavily on the founders’ minds.

Shortly after the founding of the United States, Congress passed the first in a series of laws that would come to be known as the Insurrection Act. The young nation had already faced a significant uprising against federal authority in Shays’ Rebellion, and legislators sought to clarify when a president could deploy federal troops domestically. Writ large, the Insurrection Act allows the president to deploy federal troops to combat an insurrection or to respond to a state’s unconstitutional behavior. More specifically, Title 10 U.S.C. Section 253(2) states that the president may deploy federal troops to “suppress, in a State, any insurrection, domestic violence, unlawful combination, or conspiracy” that deprives people of their constitutional rights or “obstructs the execution of the laws of the United States” when the state cannot or refuses to intervene. Critically, this portion of the statute is ambiguously worded; some scholars suggest that at its broadest, Section 253(2) could allow the president to deploy federal troops to quell a conspiracy between two citizens to break the law. Although this interpretation is considered implausible, as it would entirely nullify the Posse Comitatus Act, it does illustrate the startling ambiguity of the act. Despite its potentially broad application, the Insurrection Act has been used sparingly in American history—just 30 times.

The Posse Comitatus Act does not bar domestic military deployment

Passed in 1878, the Posse Comitatus Act (PCA) originally aimed to stop federal troops from conducting law enforcement activities in the South during Reconstruction. At the time, armed white supremacist groups sought to prevent Black Americans from exercising their rights under the 13th, 14th, and 15th amendments. President Rutherford B. Hayes deployed federal troops to stop these lawless groups, but senators from the South objected to this deployment and pushed for the enactment of the Posse Comitatus Act in an effort to stem presidential authority under the Insurrection Act.

Broadly speaking, the PCA prohibits the military from conducting federal law enforcement activity, such as detaining people, policing protests, and issuing arrest warrants. Those found in violation of the act can be fined or spend up to two years in prison. Importantly, the PCA does not outright bar domestic deployment. First, the act does not apply to all branches of the military; the U.S. Coast Guard along with state and hybrid-status National Guard troops are exempt. Second, the PCA allows the military to act in a law enforcement role “under circumstances expressly authorized by the Constitution or Act of Congress,” meaning that the statute does not apply when the president invokes the Insurrection Act.

Despite these significant exceptions to the PCA, the military often acts with “self-restraint” to avoid violating the act. In the 146 years since the PCA’s enactment, there have only been two PCA prosecutions, and neither resulted in conviction. On the civil front, in a 1996 civil action alleging PCA violations, the court ruled that the accused officers were entitled to qualified immunity—the same type of immunity that often shields law enforcement officers from allegations of police brutality.

The National Guard and the Posse Comitatus Act

The National Guard is the sole branch of the military that serves both state and federal governments. What this means in practice is that the guard can operate under one of three different statuses: 1) state active duty status, 2) federalized status, and 3) hybrid status. Hybrid status, also known as “Title 32 status,” allows troops to carry out federal assignments while still under the control of their respective states. When the Guard is acting under hybrid status, it is not subject to the PCA, which means that National Guard troops can perform federal missions without having to worry about the PCA’s bar on law enforcement activity. However, troops cannot move into hybrid status without the approval of their state governor, so presidents do not have total power to void the PCA. Also, as discussed below, hybrid troops are not immune to state or federal laws, meaning that they are not unaccountable actors.

Domestic deployment in the modern era

In the context of present-day domestic deployment, the U.S. Supreme Court has given presidents broad power to invoke the Insurrection Act. In the 1827 case Martin v. Mott, the court held that the president has exclusive authority to determine when to deploy the military domestically. Courts could intervene if the military subsequently engaged in illegal behavior, but at that point, the damage would already be done. A further complicating—and alarming—factor is the Supreme Court’s 2024 decision in Trump v. United States, which provided presidential immunity for illegal acts if done within the scope of presidential authority. As the president is commander in chief, deploying troops is likely squarely within presidential authority, meaning that a court is unlikely to hold the president accountable for an Insurrection Act order—even one that does not meet the statute’s requirements.

The most recent modern invocation of the Insurrection Act took place in 1992, when President George H.W. Bush used it in an attempt to quell the Rodney King riots in Los Angeles. On May 1, federal troops were deployed with local police and sheriffs to maintain order, but the differences between military and police training soon became apparent. In one notorious incident, the Marines and police were called to respond to a domestic disturbance at a local home. When the officers arrived, the inhabitants fired a shotgun through the front door. A policeman yelled “cover me,” meaning hold your fire but prepare to shoot as necessary. The Marines, however, “responded instantly in the way they had been trained, where ‘cover me’ means ‘provide me with cover using firepower.’” The soldiers then opened fire on the residence, shooting more than 200 bullets into the front of the house. Three children were inside the home at the time. No one involved in the incident was killed, but federal troops were pulled out of Los Angeles on May 10, just days after their initial deployment. This incident illustrates the enormous safety risks posed by deploying combat-trained troops to a civilian environment. One miscommunication could have ended civilians’ lives, children’s lives. The fact that none of the bullets hit any of the individuals involved is a matter of pure luck.

During his first administration, President Trump ordered National Guard units from 15 states deployed to Washington, D.C., to respond to civil rights protests following the murder of George Floyd. As this was an attempted “hybrid” deployment, states could choose to refuse it, and four states did so. More recently, in 2024, Speaker of the House Mike Johnson (R-LA) called on then-President Joe Biden to deploy the National Guard to deal with campus protests regarding the Israel-Palestine conflict; the president denied this request. Presidents and governors are likely wary of campus deployments following the devastating Kent State massacre. In 1970, the Ohio National Guard was deployed to quell an anti-Vietnam War protest at Kent State University; but on May 4, military units lost control of the situation and, rather than retreating, fired approximately 67 rounds over a 13-second period, killing four students—three protestors and one woman walking to class—and wounding nine others. No military personnel were convicted of any crimes related to the massacre. Every year on May 3, Kent State students hold a candlelight vigil for their fallen classmates.

This brings us to the present day, where President Donald Trump has promised to deploy the military to enforce his domestic policy agenda through mass deportations, the stamping out of First Amendment-protected protests, and, potentially, the policing of major metropolitan areas.

The present day

Hours after being sworn into office, President Trump signed an executive order declaring a national emergency at the southern border and instructing the U.S. Department of Defense to deploy troops to the region. The order further states that, within 90 days of the proclamation, the secretaries of defense and homeland security must submit a report to the president on the state of the border, including their recommendation on whether or not to invoke the Insurrection Act. If invoked, the Insurrection Act would open the door to federal troops patrolling local communities and conducting large-scale immigration raids throughout the country. An additional agency directive rescinded limits on immigration enforcement activities in “sensitive locations,” which could result in military raids at schools, churches, playgrounds, and local businesses.

The president’s domestic deployment aspirations do not stop with immigration enforcement. As mentioned above, Trump has previously advocated for using the military against “the enemy from within.” The ambiguity of this phrase is cause for significant concern. In the past, the president has called for the military to be used against political protestors. During the George Floyd protests, Trump reportedly told Gen. Mark Milley, then-chairman of the Joint Chiefs of Staff, that soldiers should “crack skulls.” He also asked Mark Esper, his defense secretary at the time, “Can’t you just shoot [the protestors]? Just shoot them in the legs or something?”

Other members of the Trump administration share the president’s militaristic inclinations. Trump’s longtime aide and deputy chief of staff Stephen Miller stated that the administration plans to use military funds to build “vast holding facilities” for immigrants waiting to be deported. During the previous Trump administration, Miller allegedly called for the deployment of 250,000 troops to the southern border. And Trump’s secretary of defense, former Fox News co-host Pete Hegseth, repeatedly supported military deployment to disrupt political protests in the aftermath of George Floyd’s death in 2020. During the previous Trump administration, the president’s impulse to deploy the military to suppress protests was tempered by cooler heads, but based on his current appointments and nominations, it is likely that if widespread protests were to break out again, individuals in Trump’s orbit would fan the flames instead of snuffing them out.

It is likely that if widespread protests were to break out again, individuals in Trump’s orbit would fan the flames instead of snuffing them out.

Yet there may be some resistance to these plans from members of the Armed Forces. Current and former U.S. service members are voicing concerns about a potential domestic deployment, with some worried about public safety due to the violence of past deployments and perceived deficiencies in training today. Retired Army Lt. Gen. Marvin Covault, who commanded an infantry division during the Rodney King riots, analyzed the current state of play: “I’m not sure we have the kind of discipline now, and at every leader level, that we had 32 years ago. That concerns me about the people you’re going to put on the ground.” Even with good intentions, military members have different training and rules of engagement than law enforcement officers, as illustrated by the “cover me” incident described above.

Hegseth has given cause for such concern by calling for a “warrior culture” in the military that focuses on “warfighting” and “lethality.” Domestic deployment should never involve “warfighting” or “lethality.” Yet soldiers trained in Hegseth’s “warrior” fashion may view the American communities to which they are deployed as modern-day battlefields, and that should be deeply concerning to all Americans.

Furthermore, taking soldiers away from their regular duties and instead using them to enforce a policy agenda could deal a significant blow to military readiness. Soldiers play an important role in national defense, keeping the nation safe from foreign adversaries. Taking troops away from this vital work would jeopardize national security by limiting the number of soldiers available in an emergency. In a world characterized by new and changing global threats to peace, Americans should be very concerned about any effort to limit military readiness.

Ensuring accountability

Importantly, though the Insurrection Act and Posse Comitatus Act may not place strong limits on domestic deployment, the military does not have carte blanche to violate the law when deployed on U.S. soil. Important safeguards are worth exploring as the nation moves toward a potential deployment.

Existing federal and state laws

Members of the military must abide by the Constitution when deployed domestically. The Insurrection Act does not allow troops to violate federal laws restricting military action or to overrule existing policies and regulations on defense support to law enforcement or the rules for the use of force. Citizens could attempt to bring a civil suit for monetary damages against federal officers for violating their constitutional rights. This is called a Bivens claim, and it requires plaintiffs to show that the federal officer 1) acted under federal authority and 2) violated an individual constitutional right. Whether or not a plaintiff can bring a Bivens claim likely depends on the court in which the case is brought. The 7th U.S. Circuit Court of Appeals in Vance v. Rumsfeld ruled against allowing civilians to bring Bivens claims against soldiers, and other lower courts have issued similar rulings. Absent a Supreme Court ruling on the subject, however, plaintiffs should not assume that they are barred from suing soldiers for constitutional violations.

On the state law front, soldiers may or may not be subject to state criminal law, depending on whether they can claim supremacy clause immunity, which shields soldiers from state prosecution when they are carrying out federal duties. However, per the 9th Circuit’s holding in Idaho v. Horiuchi, soldiers are subject to state criminal law when their actions are not reasonably within the scope of their federal duties. Put differently, if a soldier performs an act that a reasonable soldier would know to be illegal, they are not immune from state prosecution. Therefore, a soldier who unreasonably used force against civilians or unreasonably discharged their weapon could be prosecuted and convicted under state law.

When it comes to state civil law, a soldier can be held liable for conduct unrelated to their federal duties. For instance, if a soldier drove into someone’s car while out grocery shopping, that would be outside the scope of their military duties. Under the Federal Tort Claims Act (FTCA), however, plaintiffs can sue the federal government for the actions of federal officials carrying out federal missions. To use the car example from above, if a soldier drove into someone’s car while out on patrol, the victim could sue the federal government and obtain money damages through the FTCA. These claims must be brought in federal court.

Legal prohibitions under hybrid status

Under hybrid status, or Title 32, National Guard troops are subject to the same federal law and constitutional prohibitions as they are under the Insurrection Act. Citizens could bring a Section 1983 claim for money damages against state National Guard members who violate their constitutional rights; this is the state and local equivalent of the Bivens claim mentioned above. Although some attorneys suggest that courts are unlikely to allow a Section 1983 claim against National Guard troops, there is no direct Supreme Court case law on that question, so plaintiffs are not barred from bringing such a claim.

Importantly, because Title 32 troops are not “federalized” under hybrid status, they are still technically agents of their respective states, meaning that state laws restricting their conduct still apply. States seeking to ensure that their troops do not violate state law could send their attorneys general or other law enforcement personnel to monitor the conduct of their state National Guard troops.

Rules for courts-martial

Under the rules for courts-martial—a list of rules that apply when soldiers are on trial before military courts—soldiers have a duty to disobey patently unlawful orders. The duty element of this is particularly significant. Soldiers do not merely have the option to disobey an illegal or unconstitutional order; they have a duty to do so. Soldiers who do not disobey unlawful orders can be held legally accountable for their unlawful conduct, providing additional incentive for troops to be wary of following illegal orders. The standard for assessing whether an order is patently illegal is whether a reasonable individual would know that their conduct violates the law.

One notorious historical example of the duty to disobey is the My Lai massacre, in which Lt. William Calley, commander of a U.S. infantry platoon, ordered his soldiers to shoot hundreds of unarmed Vietnamese civilians. When on trial before the military court, Calley claimed that he was following the orders of his superior officer and therefore should not be held accountable for the murders. The court ruled that Calley should have known the order was “palpably illegal” because “for 100 years, it has been a settled rule of American law that even in war the summary killing of an enemy who has submitted … is murder.”

The need for further reform

Though avenues for accountability remain available, Americans cannot and should not rest on their laurels when it comes to advocating for reform. Legislators and advocates have long called for changes to the Insurrection Act. In 2020, Sen. Richard Blumenthal (D-CT) proposed amending the law to restrict the president’s power to deploy the military. He suggested that, among other things, the president be required to 1) consult with Congress before invoking the act and 2) provide evidence that the state to which he is deploying troops either requested his assistance or is refusing to enforce the law. The Brennan Center for Justice has also called for reform, suggesting that the act be modified to state that the president’s deployment order under the Insurrection Act will expire after seven days if Congress does not approve deployment through a joint resolution. The resolution would then expire after 14 days, at which point either troops would be recalled or Congress would pass another joint resolution—which, again, would last for only 14 days.

All this is to say that the fact that accountability is possible under current law should not foreclose arguments for reform. Ensuring that the Insurrection Act cannot be invoked on a presidential whim is vitally important.

Conclusion

History underscores that domestic deployment is never to be done lightly. The military and civilian worlds are fundamentally and intentionally different: One is primed for war, the other for peace. Americans should be deeply concerned about the prospect of troops carrying out missions on U.S. soil, for violence and escalation are likely to follow.

The military and civilian worlds are fundamentally and intentionally different: One is primed for war, the other for peace.

Fortunately, though laws restricting domestic deployment may be weak, Americans are not without legal recourse when it comes to challenging military misconduct. As illustrated in this report, the Constitution, federal laws, and, in certain circumstances, state constitutions and laws remain important bulwarks against government overreach. Ultimately, however, Americans cannot rely on the courts and local officials to protect them from abuses of authority conducted by domestically deployed military personnel.

The most surefire way to ensure that the military does not abuse Americans’ constitutional rights under orders from the chain of command, up to and including the president, is to ensure that the military is not deployed domestically except in the direst circumstances. The scenarios that President Trump has asserted demand domestic deployment do not rise to the standards set in nearly 250 years of the republic. Such deployments would be unprecedented historically and under the U.S. Constitution, which was created to thwart such abuses of power.

If the nation reaches the point where the military is conducting violent actions and violating the constitutional rights of the so-called “enemy within,” Americans can reasonably assume that the highest echelons of power within the executive branch will not act to rein in or hold accountable such abuses. Rather, it will be up to the states, local officials, the media, and the American people to hold perpetrators and those giving the orders accountable.

The positions of American Progress, and our policy experts, are independent, and the findings and conclusions presented are those of American Progress alone. A full list of supporters is available here. American Progress would like to acknowledge the many generous supporters who make our work possible.

Authors

Hayley Durudogan

Senior Policy Analyst

Sydney Bryant

Policy Analyst, Structural Reform and Governance

Devon Ombres

Senior Director, Courts and Legal Policy

Team

Courts and Legal Policy

The Courts and Legal Policy team works to advance reforms to make America’s legal system more accessible and just for ordinary people.

This field is hidden when viewing the form

Default Opt Ins

This field is hidden when viewing the form
This field is hidden when viewing the form
This field is hidden when viewing the form
This field is hidden when viewing the form
This field is hidden when viewing the form
This field is hidden when viewing the form
This field is hidden when viewing the form

Variable Opt Ins

This field is hidden when viewing the form
This field is hidden when viewing the form
This field is hidden when viewing the form
This field is hidden when viewing the form
This field is hidden when viewing the form
This field is hidden when viewing the form
This field is hidden when viewing the form
This field is hidden when viewing the form
This field is hidden when viewing the form
This field is hidden when viewing the form
This field is hidden when viewing the form
This field is hidden when viewing the form
This field is hidden when viewing the form
This field is hidden when viewing the form
This field is hidden when viewing the form
This field is hidden when viewing the form
This field is hidden when viewing the form
This field is hidden when viewing the form
This field is hidden when viewing the form

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.