Assessing the Cases Against Militarized Border Enforcement

While only beginning to take shape, the border control policies of the second Trump administration have a distinctively militarized character. The country is suffering from an “invasion” of unwanted migrants, according to the president, and so the natural response is to deploy government policies that amplify military strategies, technology, equipment, and personnel. Tom Homan, the incoming “border czar,” says military bases will be used as detention centers to facilitate mass deportation operations. President-elect Donald Trump has said the armed forces will be involved in these operations to the maximum extent possible under the law.  

Critics are already mobilizing against these plans in the harshest possible terms, but they are yet to coalesce around a cohesive message. Many of the earliest rebukes have taken a legal tact, with some claiming from the outset that involving the U.S. military in domestic law enforcement is expressly against the law. Others focus on what the further militarization of border control policy might imply for the rights and well-being of migrant and minority populations, irrespective of their legal status.  

It is not yet clear which, if any, of these critiques will carry weight within the legal system or among the public. As is so often the case with Trump, criticisms are diffuse and extreme in equal measure—and after so much time, it is no wonder that American ears have been deafened by the sound of alarm bells. Meanwhile, immigration hard-liners have already begun issuing a rebuttal, arguing that militarized policies are both legal and necessary to fix the country’s broken immigration system.  

This article takes stock of the arguments that already exist against Trump’s plans for border militarization in an attempt to identify those that have the greatest merit. In brief, the legal arguments against using the military for border and immigration enforcement are weaker than critics might suggest, but concerns about rights violations are legitimate and potentially worrying. Despite what immigration hard-liners might claim, further militarization of border control policies is unlikely to resolve the problems at the core of the migration debate. Despite what critics on the left might fear, there is also reason to believe the public will react against militarized policies if they prove to be ineffective, indiscriminate, or abusive. 

The Legal Limits on Using the Military

However controversial the president’s proposals may be, they are not unprecedented. They reflect a steady trend toward militarization, beginning in earnest with President Richard Nixon’s “war on drugs” and accelerating through President George W. Bush’s “war on terrorism.” In the present day, the U.S. Customs and Border Protection recruits heavily among military veterans and makes use of equipment and technology developed for the battlefield. The military itself is also an active player at the border. Overt coordinative efforts among military and domestic law enforcement are centralized through Joint Task Force-North, a joint-service operation headquartered at Fort Bliss, Texas, with the stated aim of defending the homeland against diffuse threats emanating from abroad. Military personnel have trained border control agents, assisted in surveilling the border, and have sometimes actively engaged in border patrol themselves.  

These trends toward militarization have been a cross-partisan effort. While some on the left criticized Trump for his deployment of the National Guard to the southern border in 2019, President Joe Biden would go on to declare a national emergency in 2021 and use this to justify his own use of the National Guard and active-duty personnel in border control operations.  

These more overt uses of the armed forces for border patrol are sometimes met with public outcry, but there has been remarkably little legal resistance to any of the actions taken above. The reason is simple: there are fewer legal constraints on using the military domestically than is often claimed by critics or assumed by the public.  

Arguments suggesting otherwise typically begin by citing the 1878 Posse Comitatus Act, which bars the use of the military for the purpose of law enforcement “except in such cases and under such circumstances expressly authorized by the Constitution or by Act of Congress.” But in her sweeping assessment of the military’s role in domestic law enforcement, Professor Lindsay Cohn of the Naval War College explains why the Act has simply not been the guardrail it is sometimes purported to be.1  

Understanding why requires a degree of historic context. Posse Comitatus was not passed as a means of safeguarding democratic institutions against military rule. Rather, it was passed largely at the behest of southern Democrats seeking the removal of federal troops, who had been operating in the South to protect citizens from widespread persecution of African-Americans and southern Republicans. The Act, according to Cohn, was targeted primarily at local actors in the South, and did not chiefly seek to limit presidential powers per se, which were already considerable in this area. It also applies chiefly to the Army, Navy, Marines, and Air Force, rather than the National Guard.  

It is also not the case that presidents have always abstained from using the military for domestic law enforcement. In the nineteenth century, the military was repeatedly used to put down labor strikes. In the twentieth century, President Dwight D. Eisenhower used his power under the Enforcement Acts to send federal troops to Arkansas to protect desegregation efforts. Thus, in Cohn’s words, “using the army to enforce the law has always been considered a last resort in the United States, but it has also been clearly legal.”  

What this means is that the Trump administration will likely face few legal barriers to his plan to use the armed forces in mass deportations. He may further expand his powers by invoking the Insurrection Act, although it is not clear this will be necessary. However undesirable these policies may be, they are unlikely to be struck down in the courts, especially by a favorable Supreme Court and especially if backed by the Republican Congress. 

While legal guardrails in this domain are much weaker than critics or the conventional wisdom might suggest, they are not entirely absent. In his first administration, courts ruled against Trump’s reallocation of military funds directly toward the southern border wall. Further, court rulings surrounding Posse Comitatus have made the distinction between uses of the military for direct law enforcement relative to assistance in law enforcement—the latter is expressly within the president’s power, but the latter may require explicit support from Congress, which could be difficult to secure given Republicans’ narrow majority. More likely is that Trump will begin by using the military in an indirect manner without (unneeded) legislation from Congress, and test legal constraints with more direct forms of engagement thereafter.  

Two caveats are in order before proceeding. First, just because the Trump administration is unlikely to face pushback regarding its use of the armed forces does not mean policies of mass deportation will not face resistance in the courts for other reasons (a point I return to below). Second, just because using the armed forces for border enforcement is legal does not mean that it is desirable or should be legal—these are each debates the American public should be having—but critics claiming otherwise dangerously misdirect public attention to what will likely be a losing legal argument.  

Human Rights Dimensions

If legal constraints are few, then what about critiques launched on the basis of civil and human rights violations? These arguments rest on the assumption that militarized forms of border control inappropriately mismatch the logic of warfare to the domain of immigration control and law enforcement. The results are policies that increase the extent of abuse that is likely to be experienced by migrants, asylum seekers, and U.S. citizens wrongly caught up in the process. Mass deportations would also put the United States at odds with the international human rights regime, including legal principles like non-refoulement, which bars the return of asylum seekers to areas where they are likely to persecuted. Immigration hard-liners argue either that militarized deportation policies need not come at the expense of respecting human rights, or that these negative externalities are a necessary byproduct of an effective policy matched to the scale of the illegal immigration problem. 

To begin weighing these claims against one another, the Eisenhower administration’s (derogatorily named) “Operation Wetback” is a useful starting point. In 1954, after being unsuccessfully lobbied to deploy the National Guard to conduct mass deportations, President Dwight D. Eisenhower appointed retired Lieutenant General Joseph Swing as the head of the Immigration and Naturalization Services. Swing described the problem in familiar terms. He believed the “alarming, ever increasing flood tide” of illegal migration constituted an “actual invasion” of the country that must be met with a “direct attack.”2 Hundreds of thousands of people were held in mass detention centers and forced onto overcrowded ships, busses, and vans to locations in Mexico with little regard to migrants’ individual places of origin, and little regard for their ability to survive in that context. In Congress, the crowded conditions drew parallels to the slave trade and resulted in the deaths of several individuals. There were also rampant claims of racial profiling and the wrongful detention and deportation of Mexican-American citizens.  

If Operation Wetback highlights the human rights ramifications of militarized policies, what of its efficacy? Here, the evidence is less clear. The operation succeeded in deporting vast numbers of Mexican citizens, but both legal and illegal immigration from Mexico persisted for the next several years, only to spike again in the following decade. The political appetite for the policy was also short-lived, with the operation terminating less than a year after its implementation. While some in the public welcomed the deportations, the policy also mobilized public concern and outcry for the living and working conditions of Mexican migrants and laborers, with these accusations continually dogging the Eisenhower administration for its duration. As historian Mae Ngai concludes, “[A]t best, Operation Wetback was a short-term success.”3  

Implementing similar policies today is likely to produce similar or worse outcomes. Unlike Eisenhower, Trump appears less sensitive to human rights concerns and more willing to use the military in deportation operations. Some may argue that military personnel are better trained and more professional than border agents and so they should actively reduce the incidence of abuse, but the historic record does not seem to bear this out. In 1997, for example, a U.S. Marine on a border reconnaissance mission mistakenly shot and killed Esequiel Hernández Jr., an 18-year-old American high school student who was herding goats near Redford, Texas. The United States may have one of the most professional militaries in the world, but that does not make them fit to the task of immigration control.  

In many ways, Trump will also be facing a more difficult problem than Eisenhower. Eisenhower’s policies were implemented in coordination with the Bracero Program, a temporary-worker program with Mexico, which allowed policymakers to deploy a stick-and-carrot approach to tackling illegal migration. Trump, meanwhile, appears to be wielding all stick and no carrot. Cooperation with Mexico was also easier to come by in the 1950s—the government at the time was initially supportive of U.S. deportations as a strategy to rebuild Mexico’s domestic labor base. Today, however, not only is the Mexican government less amenable, but it is also less relevant, as a significantly smaller proportion of America’s migrant population hails from Mexico. The result is that the Trump administration may succeed in detaining individuals while failing to find a foreign government who will comply with deportation processes, and it is here where Trump’s greatest legal and practical troubles may emerge.  

In brief, America’s last experience with mass deportations seems to buttress the concerns raised by today’s human and civil rights advocates, while providing less evidence supporting hard-liners’ claims about these policies being discriminant, humane, or effective.

The View from the Public

The argument so far implies that critics of border militarization should focus their attention on human rights issues and trust that, should they occur, the public will react against them. Cynics may be skeptical of this approach. They might rightly argue that the public cares greatly about immigration policies, which need not be effective to be popular. Even worse, they may fear that many on the right actively prefer repressive and militarized policies and will reward the Trump administration for following through on its promises.  

My own research suggests a somewhat less cynical view of public opinion on these issues. In a recent study with Sarah Maxey, we performed an analysis of the public’s appetite for border militarization. We asked the public about a broad variety of border control strategies that varied in terms of their degree of militarization, while holding constant the projected effectiveness of each policy in reducing illegal migration, human trafficking, drug trafficking, and transnational terrorism. Before fielding the study, we feared that the public might intrinsically prefer militarization. They may, for example, express high support for policies that made direct use of the military, or policies that featured the use of heavy weaponry and repressive tactics.  

We found that this was not the case. After accounting for a policy’s costs and effectiveness, neither side of the political spectrum had a strong or significant preference for policies that were implemented by the US Army or the National Guard. Nor did either side gravitate toward coercive strategies that featured heavily armed military-like operations. Rather, Democrats and independents actively dispreferred more militarized policies, while Republicans appeared more apathetic about how the job was done, so long as it succeeded in reducing illegal activity at the border. In this sense, the issue of militarization succeeded in polarizing the public, but only because the left actively disliked militarized policies, not because the right preferred them. Interestingly, the study also found anxieties may marginally increase both sides’ support for some forms of border militarization, but this was not their baseline preference.  

What this means is that militarization alone likely will not be enough for the Trump administration to boost its public approval. Instead, it will be incumbent on the administration to convince the public that these policies are effective, sufficiently discriminant, and minimally abusive. President Trump will gain support among some for “trying,” but not at the expense of significant externalities. There is an irony here: the public can vote for policies that portend abuse and then punish the leader who enacts it. There is also tragedy, especially if predictable abuses occur unnecessarily.  

Sources of Mobilization

To conclude, if Trump is to follow through on his campaign promises—and I believe he is legally well-positioned to do so—then opponents of these policies should focus their attention to mobilizing support around the human rights issues at the core of border militarization. They should abandon the notion that Trump cannot enact militarized policies and abandon the common throwing-spaghetti-at-the-wall approach where every possible critique is issued at its greatest volume.  

To be clear, no such abuse has yet occurred. For immigration hard-liners who believe that these policies can be implemented reasonably humanely, then it is incumbent on them to prove as much in a transparent manner. The media and human rights community, meanwhile, must monitor the situation and disseminate evidence of significant abuses, should they occur. 

Other sources of opposition will likely emerge as well. Given its high standing with the U.S. public, the armed forces have nothing to gain and much to lose from being dragged further into the issue of immigration and border control. After all, mass deportation is not what most servicemen and women had in mind when they envisioned protecting their country. U.S. employers are another source of opposition. Most immigration hard-liners prefer to ignore the fact that undocumented migrants are drawn here by U.S. industries that are more than willing to employ workers illegally. While Trump will target blue areas as much as possible, it is easy to imagine a world where he begins to face resistance from powerful interests in agricultural industries, as is already happening in some places in Europe experimenting with stricter migration laws.  

Regardless, none of the policies proposed thus far constitute a comprehensive response to widespread problems in the migration system. That would require exactly the type of bipartisan support that has proved so hard to come by in recent years. And yet progress can occur at unlikely times and stem from unlikely sources. Only time will tell whether the next four years will deliver such a moment for the immigration system, or whether partisans will continue to use disfunction as a source of political theater. 

Michael Kenwick is an Assistant Professor in the Department of Political Science at Rutgers University, New Brunswick. He is also a former Lightning Scholar at Perry World House (2023-24.)