Stephen Miller’s January 2026 announcement to Immigration and Customs Enforcement officers – telling them that they have “immunity to perform your duties” and that no “illegal alien, no leftist agitator or domestic insurrectionist” can stop them – may seem like an extreme statement outside the political mainstream.

And when ICE agents use facial recognition software to monitor immigrants and protesters, that might seem like an unacceptable invasion of people’s privacy.

While extreme, these cases are not too unexpected. Both Miller’s statements and ICE’s monitoring extend from the framework of immigration enforcement that grew from the Sept. 11, 2001, terrorist attacks.

Immigration enforcement was reorganized and reframed after 9/11, particularly through the creation of ICE and the Department of Homeland Security.

As a scholar of immigration in the U.S., I find that the growth of extreme immigration enforcement, both at the border and across the country, results from this change 25 years ago.

From criminality to terrorism

In November 2002, the Homeland Security Act created DHS. The founding of ICE followed a few months later. As the agency notes, it was part of “the single-largest government reorganization since the creation of the Department of Defense.” Immigration enforcement was folded into a national security priority whose primary purpose was to defend “homeland security.”

The notion of immigrants as potential criminals was widespread well before the creation DHS.

In 1996, for example, President Bill Clinton signed the Illegal Immigration Reform and Immigration Responsibility Act. That law expanded the number of offenses that could result in automatic deportation, including of legal residents. The act also limited judicial review of deportation cases, while the very title of the law framed people in the U.S. without legal status as lawbreaking criminals.

But after 9/11, the connection between immigration and law enforcement intensified and took on a new dimension: counterterrorism. Immigration was no longer treated as a civil issue in which immigrants were deported if found through a civil court to have violated the law.

Instead, immigrants were evaluated as possible threats to the country.

Immigration trials, such as for overstaying visas, increasingly took place in closed hearings, with the government’s secret evidence not shared with the accused. Those arrested for crossing the border illegally were imprisoned and faced [criminal prosecutions]. Expedited deportations took place at the border and across the country, even for immigrants who had been in the U.S. for years.

Further federal government practices connected immigrants to terrorism. The National Security Entry-Exit Registration System or NSEERS, introduced in 2002, required immigrant men from 25 countries – almost entirely in the Middle East, South Asia and North Africa – to register with the federal government after already residing in the country. It was framed as an effort to defend homeland security, and hundreds of people who had overstayed their visas for less than a month were detained.

United Nations human rights experts later criticized NSEERS for racial and religious profiling. Of the approximately 80,000 people registered, not a single terrorism prosecution resulted. About 14,000 were placed in deportation proceedings for visa irregularities, none for terrorism-related activity.

DHS suspended NSEERS in 2011, and it was terminated in 2016.

Lessons learned from 9/11

If the purpose of NSEERS was to identify terrorists, it failed.

But it succeeded in treating immigrants as potential terrorists. That connection has intensified since.

Federal government investment in facial recognition technology grew substantially after 9/11 with bipartisan support. The goal was to identify possible terrorists in American airports and cities.

Today, facial recognition has become a common tactic used by ICE officers to identify not just immigrants for potential detention but also citizen observers.

Additionally, privately owned detention centers grew in response to the mass arrests of immigrants. Treatment of immigrants at these centers, according to human rights advocates, has included “abuse, solitary confinement, and medical neglect.” For years, ICE detention centers have been criticized for similar conditions.

Programs like NSEERS produced fear and led to what policymakers have called self-deportation, where immigrants voluntarily leave the U.S. Today, self-deportation has become a government-endorsed program.

Research also shows that heightened immigration enforcement after 9/11 led many immigrants, even those with legal status, to withdraw from public life, avoiding schools, hospitals and work. ICE today produces the same kinds of fear.

Going beyond technical reforms

The immigration enforcement response to 9/11 set the stage on which Miller’s language and the collection of everyday Americans’ data become viable.

Under this way of thinking, if the homeland is under threat, then those who challenge immigration enforcement are “domestic terrorists.” Investigations into ICE officers are muted, for the officers are protecting the homeland against existential danger. Severe tactics to detain immigrants and condemn protesters become not only permissible but also advisable, according to advocates.

Perhaps technical reforms, such as requiring ICE agents to use body cameras or requiring ICE agents to have judicial warrants before entering homes, may limit some abuses.

But these measures do not address the underlying premise since 9/11 that immigration has become primarily viewed as a national security threat.

Pawan Dhingra does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.