Can the U.S. Still Use the Alien Enemies Act? What a 225-Year-Old Law Means Today

Most Americans have never heard of the Alien Enemies Act, yet it’s still active—and powerful. Passed in 1798, this law grants the U.S. president authority to detain foreign nationals during times of conflict. Discover its origins, how it’s been used, and why it still matters in modern debates over national security and civil liberties.

In a nation founded on liberty, one law has quietly endured since the 18th century, the Alien Enemies Act, passed in 1798. While largely forgotten by the public, this statute still sits quietly within the United States Code, fully intact, fully enforceable, and still potent. It empowers the President to detain or restrict citizens of enemy nations during times of war. And yes—it has been used.

In fact, it was just invoked again. In March 2025, President Biden issued an official proclamation invoking the Alien Enemies Act in response to the infiltration of U.S. borders by the Venezuelan criminal syndicate Tren de Aragua. Suddenly, a dusty law from the days of powdered wigs and quill pens was back in the spotlight, reigniting debates about civil liberties, immigration policy, and executive power.

But where did this law come from? Why does it still exist? And what does it mean for you, today?

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The Origins: Fear and Federal Power in 1798

The Alien Enemies Act was one of four controversial laws passed under the Alien and Sedition Acts during the presidency of John Adams. The United States was a young republic, bristling with political division and gripped by fear of war with France. The Federalist-controlled Congress responded with laws aimed at suppressing dissent and tightening control over foreigners.

Among those laws, the Alien Enemies Act (July 6, 1798) stood out for its enduring legal power. It authorized the President to detain, deport, or restrict any male over the age of 14 who was a citizen of a hostile nation—during times of declared war. Unlike its sister acts (two of which were repealed and one expired), the Alien Enemies Act was never repealed. It remains codified at 50 U.S. Code Chapter 3.

“All natives, citizens, denizens or subjects of the hostile nation or government… shall be liable to be apprehended, restrained, secured and removed, as alien enemies.” — The Avalon Project

Its language is simple but expansive. It requires no criminal conviction. It does not define what makes a person an “enemy.” It gives the President unilateral authority to act against entire nationalities—and courts have historically upheld it.

From World Wars to Wartime Internment: A Tool for Presidents

The Act saw major use during World War I, when German nationals were detained and monitored under presidential orders. It was used again in World War II as part of the legal scaffolding for the internment of Japanese, German, and Italian immigrants.

While Executive Order 9066 was the most infamous wartime measure, the Alien Enemies Act gave it legal legs—allowing broad action against those deemed threats without evidence of wrongdoing.

The Act permits the President to detain any foreign national from an enemy nation during wartime—even if that person is a lawful permanent resident. — Brennan Center

Still in Force: A 2025 Invocation

In March 2025, President Biden invoked the Alien Enemies Act in a new context: to address organized infiltration by Tren de Aragua, a violent Venezuelan gang allegedly operating within U.S. borders.

The presidential proclamation authorized enhanced surveillance, detentions, and immigration restrictions on foreign nationals linked to the group.

The move sparked bipartisan debate. Was it a valid use of an old law in a modern crisis—or an overstep of executive power? Either way, it reminded America: the law is still alive.

What If Cyberwar Becomes a Trigger?

What happens if a future administration declares cyberwarfare or AI-based information warfare as a “conflict”? Could the Alien Enemies Act be triggered against foreign nationals from countries accused of hacking, like Russia or China?

Legal scholars say yes. The law is vague enough that a president could potentially invoke it without formal congressional war declarations especially if intelligence agencies confirm a cyberattack or national security breach.

That’s not science fiction. It’s legally plausible under current U.S. law.

Security vs. Liberty: A 21st-Century Struggle

The Alien Enemies Act embodies a centuries-old dilemma: how much power should the government hold in times of crisis—and at what cost to individual freedom? Enacted in an era of foreign threats and internal paranoia, the law reflects a deep-rooted instinct to choose control over civil liberties when fear dominates the national mood.

That tension is no less relevant today.

In a time of rising global conflict, cyberwarfare, and transnational crime, the justification for strong executive action may feel urgent. But laws like the Alien Enemies Act remind us that “wartime” can be loosely defined, and that emergency powers, once activated, are rarely given back.

It forces Americans to confront hard questions:

Should a law from 1798 still dictate modern immigration and detention policy?

Can national security be maintained without resorting to profiling by nationality or country of origin?

What checks and balances truly exist when the President can target entire groups without trials or due process?

The blurring lines between crime, terror, and war have made these questions harder, not easier. Today’s enemies may not wear uniforms or come from a single state. But once the legal power to detain or expel based on nationality is used, it can set a precedent that extends beyond war zones into politics, prejudice, or fear itself.

This isn’t just a legal debate. It’s a reflection of what kind of democracy the United States wants to be one guided by laws written in fear, or one shaped by principles that withstand it.

Reform or Repeal? A Legal Debate

Civil liberties advocates, including those at the Brennan Center, have called for the repeal or revision of the Alien Enemies Act.

Proposed reforms include:

Adding a sunset clause for review

Requiring judicial oversight for detentions

Narrowing the definition of “enemy” to active threats

Prohibiting its use against permanent residents or asylum seekers

But until Congress acts, the law remains a loaded weapon of executive authority.

Final Thought: The Law Is Still Alive. The Choice Is Ours.

The Alien Enemies Act is more than a historical relic. It’s a reminder that laws born in fear rarely die on their own. Still active after 225 years, it grants sweeping powers that bypass the usual checks and balances of justice. Its very survival challenges how we define threats and how easily we trade liberty for control when fear returns.

Whether it protects or endangers depends not just on the law itself—but on who decides to use it next.