The Changing Face of the Department of Homeland Security

[Editor's note: This piece is part of Lawfare's collection "9/11 at 25: The Legal Architecture of the War on Terror, Twenty-Five Years On," examining how 9/11 remains—or doesn't—embedded in current legal and policy frameworks, a quarter century after the attacks. Read the full collection here.]

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The terrorist attacks of Sept. 11, 2001, were a shock to the American system. For the first time since Pearl Harbor (or if you prefer historical accuracy, perhaps since the War of 1812), an enemy caused death and destruction in the American homeland.

The result was the single most significant strategic reorientation of American policy since the New Deal/World War II era. The U.S. went to war in Iraq and Afghanistan to take the fight to the enemy. It reorganized intelligence gathering to try to prevent missing signals again.

And, for purposes of internal security, the United States created a massive new department—the Department of Homeland Security—in an effort to unify its domestic law enforcement, counter-terrorism, and border security systems.

For nearly 230 years, the United States operated without a unified internal federal law enforcement presence. It went 230 years, as well, without a unified approach to the national border. On the cusp of 9/11, America’s approach to internal security (which is now called homeland security) was a patchwork of agencies and authorities.

Today, it still is—but less so. The creation of the Department of Homeland Security in 2003 was a sea change for America. And that change still resonates on the 25^th anniversary of 9/11 and the Department of Homeland Security's founding. Perhaps even more than the overseas war or the intelligence reorganization, the creation of the Department of Homeland Security continues to have ongoing implications in the United States.

In a crudely symbolic way, those implications were made manifest by a recent announcement from the department on the cusp of the 9/11 anniversary: Where, since its inception, the eagle at the center of the department’s logo had faced toward the peaceful olive branches in one of its talons, Secretary Markwayne Mullin proudly announced that it would now face toward the arrows in its other talon. The department, Mullin declared, was going to war against “bad actors” in our backyard.

This dismaying change in rhetorical emphasis prompts the need for real reflection: Why has the creation of the Department of Homeland Security fallen short of its post-9/11 expectations? How, to put it bluntly, did the Department of Homeland Security go from hunting al-Qaeda to hunting undocumented immigrants the current president has claimed are “poisoning the blood of our nation”?  

It’s a long, sad story.

The Beginning

At the moment the plane hit the second tower, I was in a court hearing with John Roberts (of all people). Nobody came into the hearing to tell us what had happened, and when we emerged three hours later, the world had changed. It had changed in small ways, obviously—I wound up cancelling a trip to Brazil planned for three days later. But it also changed in much larger ways—the shock of the events reset American perspectives on security in a fundamental way.

The impetus for the creation of the Department of Homeland Security lay in the perceived security failures on that day. In colloquial parlance, “the lights were blinking red,” and yet the United States did nothing to stop the attacks. A long-standing set of rules erected a near-impermeable wall between foreign intelligence gathering and domestic law enforcement. The “wall” was thought to be a bulwark of liberty—and perhaps it was. But as the 9/11 Commission made clear, that liberty came at a very real cost.

Thus, most notably, in the aftermath of 9/11, Americans agreed to reset the careful balance between liberty and security. Though Ben Franklin castigated any who would trade liberty for security, the reality is that America’s balance has swung back and forth, advancing security in times of crisis and liberty in times of peace. Sept. 11 gave a real push to the pendulum in the security direction. This transition is, thematically, at the heart of the creation of the Department of Homeland Security, and of all of the problems and tensions that have arisen since its creation.

The Department of Homeland Security was not authorized until 2002, more than a year after the 9/11 attacks. The delay was, in part, due to a reluctance to create a large new institution and resistance to this changed paradigm. Nevertheless, in March 2003, the Department of Homeland Security opened its doors.

Department of Homeland Security 1.0 – The Theory

The first secretary of the Department of Homeland Security, Tom Ridge, is (probably apocryphally) said to have likened the creation of the department to trying to build an airplane while in flight. The organization was created without a coherent strategic theory and had to build one on the fly. True to its origins, the first phase of the Department of Homeland Security focused like a laser on counter-terrorism—the target was al-Qaeda and the threat was from overseas. So, the three-part strategic theory that the department eventually developed responded to that threat: push the borders out, defend the homeland in depth, and allocate resources based on perceived risk.

The first part of the new theory was to redefine what the borders are. Much of this was simple—the Department of Homeland Security unified immigration agents (who had been at the Department of Justice) with customs agents (from the Department of Commerce) and agriculture inspectors. Now arrivals would see “One Face” at the border.

Meanwhile, the Department of Homeland Security worked hard to push the borders out from the physical border. The theory was that a threat intercepted at, say, the port in Singapore was a threat that didn’t come to U.S. shores. The United States deployed customs and immigration agents overseas and began doing as much screening as possible away from the United States.

The more challenging problem was finding the new threats. The terrorists didn’t wear uniforms; they moved through society largely indistinguishable from anyone else. The Department of Homeland Security was faced with the problem of sorting through a large haystack for a few needles. Emblematic of the problem was the Total Information Awareness (TIA) mass detection program (a Defense Advanced Research Projects Agency project) that sounded amazingly like Big Brother from 1984.

Though TIA was rejected by Congress and the public, the principle of targeted inspection and enforcement nonetheless became embedded in the American experience. In the commercial sector, programs like the Customs Trade Partnership Against Terrorism identified trusted shippers whose containers were subject to less inspection. The same idea was deployed at U.S. airports—identifying trusted travelers— which led to the creation of TSA Pre-Check and Global Entry. At the core of all of these programs was a simple idea: The more data the U.S. collected about a shipper or traveler, the more confident it could be in its assessment of the risk they posed.  In the age of data, the pendulum swung—hard—away from privacy and liberty.

Not all of the new pieces at the Department of Homeland Security fit this theory. Some, like the Coast Guard and the Transportation Security Administration (TSA), were partially directed toward the new counter-terror/border control mission. But others, like the Secret Service and the Federal Emergency Management Agency, seemed to have no real place at all. And some pieces, like the FBI’s counterterrorism mission, that would have fit well, were excluded for mostly political reasons. As those who made the final decisions will tell it, forming the Department of Homeland Security was as much about the art of the possible as it was about the best answer.

Perhaps the most problematic decision of all—one that resonates today—was the agreement to transition all of immigration adjudication and enforcement to the Department of Homeland Security. This included not just border control and entry/exit (which made some sense), but also interior enforcement and investigations, as well as naturalization and citizenship.

 Department of Homeland Security 2.0 – The Threat Comes Ashore

At some point the terrorist threat mutated. Core to the initial strategy was the assumption that the threat originated overseas. To interdict it, the U.S. had to limit terrorist travel, monitor terrorist communications, and track the flow of terrorist money.

In the time of the Department of Homeland Security 2.0, the threat came ashore. Instead of sending fighters from the Pakistani hinterlands, al-Qaeda needed to only send ideas. Using the (then-relatively) new social networks, foreign terrorists needed only to recruit assets in place and radicalize them to act. No travel needed; no tactical or operational control; and typically, not even any money. The new terrorists were often self-funded. 

So the Department of Homeland Security had to change to focus on a threat now embedded in, well, the homeland. But that brought new challenges. Where, initially, the Department of Homeland Security had looked at the conduct of foreigners, now a more substantial fraction of those under scrutiny were American citizens or lawful residents. The swing of the pendulum now began to have a real “bite” for everyday Americans.

The most salient problem in this change of focus was distinguishing the fine line between speech that is political and speech that is intended to incite violence and radicalization. America’s commitment to free speech makes regulation of violent rhetoric particularly difficult. As the Department of Homeland Security turned its focus inward, it, of necessity, began to redraw that boundary.

The other significant change arising from an inward focus by the Department of Homeland Security arose from the different nature of the cyber-domain. Where, early on in the lifetime of threats to the homeland from offshore had to cross hard physical borders, now threat actors could disrupt infrastructure at a distance. This reorientation required greater Department of Homeland Security interaction with the private sector, the devotion of new resources, more scrutiny of Americans at home, and a strategic focus on actions that occurred inside the national borders. 

Once again, albeit for good reasons, the impetus of Department of Homeland Security action led to a further disruption of the privacy/liberty balance.

Department of Homeland Security 2.5 – Domestic Threats

The next transition—which also made sense at the time—shifted the focus from religiously based ideological threats to a broader set of potential threats to internal security. As a result, once the mission of the department was unmoored from its initial focus on an overseas-based radical Muslim ideology, it started to become imbued with a more political tinge. How one thought about Department of Homeland Security activities was now more a reflection of one’s political predisposition. Under the Biden administration, for example, many conservatives saw a Department of Homeland Security that they perceived as deployed against their political beliefs.

To cite just one example, consider social media, which is awash in disinformation. In the last 15 years, it has become clear that much of it is created by troll accounts controlled by America’s adversaries. It is intended to (and succeeds in) sowing dissent and doubt—about vaccines, elections, the integrity of democracy, and much more. 

In an effort to combat this phenomenon, the Department of Homeland Security thought to put together a Disinformation Governance Board—an initiative intended not to censor information, but to combat false information with authoritative, truthful responses. Sadly, this was not to be. Much of the disinformation was already accepted wisdom in some circles (mostly conservative ones), and efforts to provide a government-sponsored response were largely viewed as the department putting its thumb on one side of the scales. The effort quickly collapsed in a storm of political outrage.

Likewise, the Department of Homeland Security came to the view that armed militia within the United States posed a threat to our internal security. But even the simplest efforts to map and understand the phenomenon were seen as overly political and were quickly shut down.

Even in making the attempt, however, the Department of Homeland Security had crossed an important line. In the service of internal security, it had taken to scrutinizing American citizens, assessing them as potential threats. Once crossed, that line could not be reestablished—the department’s engagement in internal American politics had taken another step toward enhanced security, at some perceived cost to liberty.

Department of Homeland Security 3.0 – The Immigration Pivot

The latest step in the transformation of the Department of Homeland Security has occurred in the last few years as the Trump administration has repurposed Homeland Security authorities even further away from their initial focus. Today, the Trump administration has identified immigrants as the internal threat and has increasingly directed department resources toward that end. With the change in focus, the Department of Homeland Security has diminished almost all of its counterterrorism mission—even TSA is now enlisted in immigration enforcement.

One clear way to see the long-term transformation of the Department of Homeland Security from counterterrorism to domestic law enforcement is to look at its efforts to counter weapons of mass destruction. At the department’s foundation was one of the most significant fears: that terrorists would succeed in importing biological or nuclear weapons into the United States. The response—led by a Countering Weapons of Mass Destruction Office (CWMD) within the Department of Homeland Security—was a crash program to deploy nuclear detectors at the border and to install biological detectors around the nation. 

Early in the second Trump administration, CWMD was disbanded. Its responsibilities have been distributed around the department and to other agencies. Many of its resources have been repurposed to other domestic efforts. Nothing symbolizes the changing focus of the department more poignantly than the end of CWMD. To what end remains to be seen.

That the United States has strayed from the original purpose of the Department of Homeland Security should be self-evident. One need only reflect on how Immigration and Customs Enforcement (ICE) operations have changed. In the winter of 2025, there was civil unrest in Minneapolis. ICE agents roamed the streets hunting illegal immigrants. Protesters rallied to stop them. At the end of the winter, Alex Pretti and Renee Good were dead at the hands of ICE agents. Over time, the ICE assault on the city—known as Operation Metro Surge—faded away, as it became a political liability. 

But ICE didn’t stop. Today it acts in more tactically subtle ways—stopping immigrants on airplanes, for example—but it is even more effective. In July 2026, ICE arrested more than 50,000 immigrants—a new record for the Trump administration.

The salience of immigration issues in today’s political environment cannot be overstated. The transformation of the Department of Homeland Security into an immigration enforcement-first agency is palpable. Homeland Security Investigations, for example, which used to do sophisticated export/import criminal matters, now rides shotgun to ICE.

Meanwhile, the transformation of ICE into a domestic brute squad continues apace.  Masks, shootings, electric gloves, stalking in churches and courthouses—the list goes on. All of it reflects a sea change in the aggressiveness with which members of the Department of Homeland Security and ICE approach their jobs. And the civilian response has, likewise, been enormous. 

As Trump took office, if you had asked the average citizen to name a Department of Homeland Security component, the only one they likely could have named is TSA.  Today, ICE has become such a prominent focus of public attention that calls for its abolition are gaining traction. The Department of Homeland Security is now synonymous with ICE, and its counter-terrorism mission is all but forgotten.

What’s Next?

Where does this leave the United States now? The Department of Homeland Security has strayed quite far from its original conception. And though the terrorist threat has seemed to fade, recent events (for example, Iran’s hack of domestic water supplies) suggest that external threats to the homeland have not gone away completely and may be only a short distance from full revival. The strategic vulnerabilities that drove the department’s initial formation have not vanished.

But the Department of Homeland Security has become a tainted brand. Though each move was operationally sensible (save perhaps the latest obsessive focus on immigration), the end result is a department that almost nobody supports. Conservatives fear its internal focus on domestic dissent; liberals, its characteristic as an internal security force.